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[#]: collector: (lujun9972)
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[#]: translator: (bodhix)
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[#]: reviewer: ( )
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[#]: publisher: ( )
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[#]: url: ( )
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[#]: reviewer: (wxy)
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[#]: publisher: (wxy)
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[#]: url: (https://linux.cn/article-10804-1.html)
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[#]: subject: (How to Restart a Network in Ubuntu [Beginner’s Tip])
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[#]: via: (https://itsfoss.com/restart-network-ubuntu)
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[#]: author: (Sergiu https://itsfoss.com/author/sergiu/)
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如何在 Ubuntu 中重启网络【新手提示】
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Linux 初学者：如何在 Ubuntu 中重启网络
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======
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你[是否正在使用基于 Ubuntu 的系统，然后发现无法连接网络][1]？你一定会很惊讶，很多很多的问题都可以简单地通过重启服务解决。
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你[是否正在使用基于 Ubuntu 的系统，然后发现无法连接网络][1]？你一定会很惊讶，很多的问题都可以简单地通过重启服务解决。
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在这篇文章中，我会介绍在 Ubuntu 或者其他 Linux 发行版中重启网络的几种方法，你可以根据自身需要选择对应的方法。这些方法基本分为两类：
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@ -18,11 +18,11 @@
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### 通过命令行方式重启网络
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如果你使用的 Ubuntu 服务器版，那么你已经在使用命令行终端了。如果你使用的是桌面版，那么你可以通过快捷键 Ctrl+Alt+T [Ubuntu 键盘快捷键][3] 打开命令行终端。
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如果你使用的 Ubuntu 服务器版，那么你已经在使用命令行终端了。如果你使用的是桌面版，那么你可以通过快捷键 `Ctrl+Alt+T` [Ubuntu 键盘快捷键][3] 打开命令行终端。
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在 Ubuntu 中，有多个命令可以重启网络。这些命令，一部分或者说大部分，也适用于在 Debian 或者其他的 Linux 发行版中重启网络。
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#### 1\. network manager service
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#### 1、network manager 服务
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这是通过命令行方式重启网络最简单的方法。它相当于是通过图形化界面重启网络（重启 Network-Manager 服务）。
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@ -32,17 +32,17 @@ sudo service network-manager restart
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此时，网络图标会消失一会儿然后重新显示。
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#### 2\. systemd
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#### 2、systemd
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**service** 命令仅仅是该命令的一个封装（同样的还有 init.d 系列脚本和 Upstart 相关命令）。 **systemctl** 命令的功能远多于 **service** 命令。通常我更喜欢使用这个命令。
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`service` 命令仅仅是这个方式的一个封装（同样的也是 init.d 系列脚本和 Upstart 相关命令的封装）。`systemctl` 命令的功能远多于 `service` 命令。通常我更喜欢使用这个命令。
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```
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sudo systemctl restart NetworkManager.service
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```
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这时，网络图标又会消失一会儿。 如果你想了解 **systemctl** 的其他选项, 可以参考 man 帮助文档。
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这时，网络图标又会消失一会儿。 如果你想了解 `systemctl` 的其他选项, 可以参考 man 帮助文档。
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#### 3\. nmcli
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#### 3、nmcli
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这是 Linux 上可以管理网络的另一个工具。这是一个功能强大而且实用的工具。很多系统管理员都喜欢使用该工具，因为它非常容易使用。
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@ -60,11 +60,11 @@ sudo nmcli networking on
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你可以通过 man 帮助文档了解 nmcli 的更多用法。
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#### 4\. ifup & ifdown
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#### 4、ifup & ifdown
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这两个命令直接操作网口，切换网口是否可以收发包的状态。这是 [Linux 中最应该了解的网络命令][4] 之一。
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使用 ifdown 关闭所有网口，再使用 ifup 重新启用网口。
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使用 `ifdown` 关闭所有网口，再使用 `ifup` 重新启用网口。
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通常推荐的做法是将这两个命令一起使用。
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@ -72,9 +72,9 @@ sudo nmcli networking on
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sudo ifdown -a && sudo ifup -a
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```
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**注意：** 这种方法不会让网络图标从系统托盘中消失，另外，你也无法进行网络连接。
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注意：这种方法不会让网络图标从系统托盘中消失，另外，各种网络连接也会断。
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**其他工具： nmtui （点击展开）**
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#### 补充工具： nmtui
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这是系统管理员们常用的另外一种方法。它是在命令行终端中管理网络的文本菜单工具。
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@ -86,21 +86,21 @@ nmtui
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![nmtui Menu][5]
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**注意** 在 **nmtui** 中，可以通过 **up** 和 **down 方向键** 选择选项。
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注意：在 nmtui 中，可以通过 `up` 和 `down` 方向键选择选项。
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选择 **Activate a connection** ：
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选择 “Activate a connection”：
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![nmtui Menu Select "Activate a connection"][6]
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按下 **Enter** 键，打开 **connections** 菜单。
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按下回车键，打开 “connections” 菜单。
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![nmtui Connections Menu][7]
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接下来，选择前面带 **星号 （*）** 的网络。在这个例子中，就是 MGEO72。
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接下来，选择前面带星号（*）的网络。在这个例子中，就是 MGEO72。
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![Select your connection in the nmtui connections menu.][8]
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按下 **Enter** 键。 **关闭** 你的网络连接。
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按下回车键。 这就将“停用”你的网络连接。
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![nmtui Connections Menu with no active connection][9]
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@ -108,19 +108,19 @@ nmtui
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![Select the connection you want in the nmtui connections menu.][10]
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按下 **Enter** 键。这样就重启了所选择的网络连接。
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按下回车键。这样就重新激活了所选择的网络连接。
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![nmtui Connections Menu][11]
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双击 **Tab** 键，选择 **Back** ：
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按下 `Tab` 键两次，选择 “Back”：
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![Select "Back" in the nmtui connections menu.][12]
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按下 **Enter** 键，回到 **nmtui** 的主菜单。
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按下回车键，回到 nmtui 的主菜单。
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![nmtui Main Menu][13]
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选择 **Quit** ：
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选择 “Quit” ：
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![nmtui Quit Main Menu][14]
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@ -132,9 +132,9 @@ nmtui
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显然，这是 Ubuntu 桌面版用户重启网络最简单的方法。如果这个方法不生效，你可以尝试使用前文提到的命令行方式重启网络。
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NM 程序是 [NetworkManager][15] 的系统托盘程序标志。我们将使用它来重启网络。
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NM 小程序是 [NetworkManager][15] 的系统托盘程序标志。我们将使用它来重启网络。
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首先，查看顶部状态栏。 你会在系统托盘找到一个网络图标 （因为我使用 Wi-Fi，所以这里是一个 Wi-Fi 图标）。
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首先，查看顶部状态栏。你会在系统托盘找到一个网络图标 （因为我使用 Wi-Fi，所以这里是一个 Wi-Fi 图标）。
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接下来，点击该图标（也可以点击音量图标或电池图标）。打开菜单。选择 “Turn Off” 关闭网络。
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@ -160,7 +160,7 @@ Ubuntu 没有可以直接 “刷新 WiFi 网络” 的选项，它有点隐蔽
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选择对应的网络修改你的 WiFi 连接。
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你无法马上看到可用的无线网络列表。打开网络列表之后，大概需要 5 秒才会显示其他可用的无线网络。
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你无法马上看到可用的无线网络列表。打开网络列表之后，大概需要 5 秒才会显示其它可用的无线网络。
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![Select another wifi network in Ubuntu][19]
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@ -168,7 +168,7 @@ Ubuntu 没有可以直接 “刷新 WiFi 网络” 的选项，它有点隐蔽
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现在，你就可以选择你想要连接的网络，点击连接。这样就完成了。
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**总结**
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### 总结
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重启网络连接是每个 Linux 用户在使用过程中必须经历的事情。
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@ -184,7 +184,7 @@ via: https://itsfoss.com/restart-network-ubuntu
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作者：[Sergiu][a]
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选题：[lujun9972][b]
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译者：[bodhix](https://github.com/bodhix)
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校对：[校对者ID](https://github.com/校对者ID)
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校对：[wxy](https://github.com/wxy)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
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78
published/201904/20180718 3 Emacs modes for taking notes.md
Normal file
78
published/201904/20180718 3 Emacs modes for taking notes.md
Normal file
@ -0,0 +1,78 @@
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[#]: collector: (lujun9972)
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[#]: translator: (lujun9972)
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[#]: reviewer: (wxy)
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[#]: publisher: (wxy)
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||||
[#]: url: (https://linux.cn/article-10792-1.html)
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[#]: subject: (3 Emacs modes for taking notes)
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[#]: via: (https://opensource.com/article/18/7/emacs-modes-note-taking)
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[#]: author: (Scott Nesbitt https://opensource.com/users/scottnesbitt)
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用来记笔记的三个 Emacs 模式
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======
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> 借助这些 Emacs 模式轻松记录信息。
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不管你从事哪种工作，你都无可避免地需要记笔记。而且可能还不是一点点。现在这年头，大家都开始以数字的形式来记笔记了。
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开源软件爱好者有多种途径来以电子的方式记下他们的创意、想法和研究过程。你可以使用 [网页工具][1]，可以使用 [桌面应用][2]，或者你也可以 [使用命令行工具][3]。
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如果你使用 [Emacs][4]（伪装成文本编辑器的强力操作系统)，有多个<ruby>模式<rt>mode</rt></ruby>可以帮你有效地记录笔记。我们这里列举三个例子。
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### Deft
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在少数情况下，我只能使用 Mac时，有一个工具是我不能缺少的：[nvALT][5] 笔记应用。[Deft 模式][6] 为 Emacs 带来了 nvALT 式的体验。
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Deft 将你的笔记以文本文件的形式存储在电脑中的某个文件夹中。当你进入 Deft 模式，你会看到一系列的笔记及其摘要。这些摘要其实就是文本文件的第一行。若第一行是 Markdown、LaTeX，甚至 Emacs Org 模式的格式的话，Deft 会忽略掉这些格式而只显示文本内容。
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要打开笔记，只需要向下滚动到该笔记的位置然后按下回车即可。然而 Deft 不仅仅只是这样。根据 Deft 开发者 Jason Blevins 的说法，它的*主要操作是搜索和过滤*。Deft 的实现方式简单而有效。输入关键字然后 Deft 会只显示标题中包含关键字的笔记。这在你要从大量笔记中找到某条笔记时非常有用。
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### Org 模式
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如果本文没有包含 [Org 模式][7] 的话，那么我可能会被人所诟病。为什么？它可以说是 Emacs 中最灵活、使用最广泛的记录笔记的方式了。以正确的方式使用它，Org 模式可以极大地增强记笔记的能力。
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Org 模式的主要优势在于它组织笔记的方式。在 Org 模式中，一个笔记文件会被组织成一个巨大的大纲。每个章节就是大纲里的一个节点，你可以对它进行展开和折叠。这些章节又可以有子章节，这些子章节也可以展开和折叠。这不仅使你一次只关注于某个章节，而且可以让你浏览整个大纲。
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你可以在多个章节之间 [进行互联][8]，无需通过剪切和复制就能快速移动章节，以及 [附加文件][9] 到笔记中。Org 模式支持带格式的字符和表格。如果你需要转换笔记到其他格式，Org 模式也有大量的[导出选项][10]。
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### Howm
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当我使用 Emacs 已经成为一种习惯时，[howm][11] 马上就成为我严重依赖的模式之一了。虽然我特别喜欢使用 Org 模式，但 howm 依然占有一席之地。
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Howm 就好像是一个小型维基。你可以创建笔记和任务列表，还能在它们之间创建链接。通过输入或点击某个链接，你可以在笔记之间跳转。如果你需要，还可以使用关键字为笔记添加标签。不仅如此，你可以对笔记进行搜索、排序和合并。
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Howm 不是最漂亮的 Emacs 模式，它的用户体验也不是最佳。它需要你花一点时间来适应它，而一旦你适应了它，记录和查找笔记就是轻而易举的事情了。
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--------------------------------------------------------------------------------
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via: https://opensource.com/article/18/7/emacs-modes-note-taking
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作者：[Scott Nesbitt][a]
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选题：[lujun9972][b]
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译者：[lujun9972](https://github.com/lujun9972)
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||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
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|
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[a]: https://opensource.com/users/scottnesbitt
|
||||
[b]: https://github.com/lujun9972
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[1]: https://opensource.com/alternatives/evernote
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[2]: https://opensource.com/life/16/9/4-desktop-note-taking-applications
|
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[3]: https://opensource.com/article/18/3/command-line-note-taking-applications
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[4]: https://www.gnu.org/software/emacs/
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[5]: http://brettterpstra.com/projects/nvalt/
|
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[6]: https://jblevins.org/projects/deft/
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[7]: https://orgmode.org/
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[8]: https://orgmode.org/org.html#Hyperlinks
|
||||
[9]: https://orgmode.org/org.html#Attachments
|
||||
[10]: https://orgmode.org/org.html#Exporting
|
||||
[11]: https://howm.osdn.jp/
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@ -1,55 +1,56 @@
|
||||
Sensu 监控入门
|
||||
======
|
||||
> 这个开源解决方案可以简单而有效地监控你的云基础设施。
|
||||
|
||||
|
||||
|
||||
Sensu 是一个开源基础设施和应用程序监控解决方案，它监控服务器、相关服务和应用程序健康状况，并通过第三方集成发送警报和通知。Sensu 用 Ruby 编写，可以使用 [RabbitMQ][1] 或 [Redis][2] 来处理消息，它使用 Redis 来存储数据。
|
||||
Sensu 是一个开源的基础设施和应用程序监控解决方案，它可以监控服务器、相关服务和应用程序健康状况，并通过第三方集成发送警报和通知。Sensu 用 Ruby 编写，可以使用 [RabbitMQ][1] 或 [Redis][2] 来处理消息，它使用 Redis 来存储数据。
|
||||
|
||||
如果你想以一种简单而有效的方式监控云基础设施，Sensu 是一个不错的选择。它可以与你组织已经使用的许多现代 DevOps 堆栈集成，比如 [Slack][3]、[HipChat][4 ] 或 [IRC][5]，它甚至可以用 [PagerDuty][6] 发送移动或寻呼机警报。
|
||||
如果你想以一种简单而有效的方式监控云基础设施，Sensu 是一个不错的选择。它可以与你的组织已经使用的许多现代 DevOps 组件集成，比如 [Slack][3]、[HipChat][4] 或 [IRC][5]，它甚至可以用 [PagerDuty][6] 发送移动或寻呼机的警报。
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||||
|
||||
Sensu 的[模块化架构][7]意味着每个组件都可以安装在同一台服务器上或者在完全独立的机器上。
|
||||
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||||
### 结构
|
||||
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||||
Sensu 的主要通信机制是 `Transport`。每个 Sensu 组件必须连接到 `Transport` 才能相互发送消息。`Transport` 可以使用 RabbitMQ（在生产中推荐使用）或 Redis。
|
||||
Sensu 的主要通信机制是 Transport。每个 Sensu 组件必须连接到 Transport 才能相互发送消息。Transport 可以使用 RabbitMQ（在生产环境中推荐使用）或 Redis。
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||||
|
||||
Sensu 服务器处理事件数据并采取行动。它注册客户端并使用过滤器、增变器和处理程序检查结果和监视事件。服务器向客户端发布检查说明，Sensu API 提供 RESTful API，提供对监控数据和核心功能的访问。
|
||||
|
||||
[Sensu 客户端][8]执行 Sensu 服务器安排的检查或本地检查定义。Sensu 使用数据存储（Redis）来保存所有的持久数据。最后，[Uchiwa][9] 是与 Sensu API 进行通信的 Web 界面。
|
||||
|
||||
![sensu_system.png][11]
|
||||
![][11]
|
||||
|
||||
### 安装 Sensu
|
||||
|
||||
#### 条件
|
||||
|
||||
* 一个 Linux 系统作为服务器节点（本文使用了 CentOS 7）
|
||||
* 要监控的一台或多台 Linux 机器（客户机）
|
||||
* 一个 Linux 系统作为服务器节点（本文使用了 CentOS 7）
|
||||
* 要监控的一台或多台 Linux 机器（客户机）
|
||||
|
||||
#### 服务器侧
|
||||
|
||||
Sensu 需要安装 Redis。要安装 Redis，启用 EPEL 仓库：
|
||||
|
||||
```
|
||||
$ sudo yum install epel-release -y
|
||||
|
||||
```
|
||||
|
||||
然后安装 Redis：
|
||||
|
||||
```
|
||||
$ sudo yum install redis -y
|
||||
|
||||
```
|
||||
|
||||
修改 `/etc/redis.conf` 来禁用保护模式，监听每个地址并设置密码：
|
||||
|
||||
```
|
||||
$ sudo sed -i 's/^protected-mode yes/protected-mode no/g' /etc/redis.conf
|
||||
|
||||
$ sudo sed -i 's/^bind 127.0.0.1/bind 0.0.0.0/g' /etc/redis.conf
|
||||
|
||||
$ sudo sed -i 's/^# requirepass foobared/requirepass password123/g' /etc/redis.conf
|
||||
|
||||
```
|
||||
|
||||
启用并启动 Redis 服务：
|
||||
|
||||
```
|
||||
$ sudo systemctl enable redis
|
||||
$ sudo systemctl start redis
|
||||
@ -60,6 +61,7 @@ Redis 现在已经安装并准备好被 Sensu 使用。
|
||||
现在让我们来安装 Sensu。
|
||||
|
||||
首先，配置 Sensu 仓库并安装软件包：
|
||||
|
||||
```
|
||||
$ sudo tee /etc/yum.repos.d/sensu.repo << EOF
|
||||
[sensu]
|
||||
@ -73,6 +75,7 @@ $ sudo yum install sensu uchiwa -y
|
||||
```
|
||||
|
||||
让我们为 Sensu 创建最简单的配置文件：
|
||||
|
||||
```
|
||||
$ sudo tee /etc/sensu/conf.d/api.json << EOF
|
||||
{
|
||||
@ -85,6 +88,7 @@ EOF
|
||||
```
|
||||
|
||||
然后，配置 `sensu-api` 在本地主机上使用端口 4567 监听：
|
||||
|
||||
```
|
||||
$ sudo tee /etc/sensu/conf.d/redis.json << EOF
|
||||
{
|
||||
@ -107,6 +111,7 @@ EOF
|
||||
```
|
||||
|
||||
在这两个文件中，我们将 Sensu 配置为使用 Redis 作为传输机制，还有 Reids 监听的地址。客户端需要直接连接到传输机制。每台客户机都需要这两个文件。
|
||||
|
||||
```
|
||||
$ sudo tee /etc/sensu/uchiwa.json << EOF
|
||||
{
|
||||
@ -125,14 +130,16 @@ $ sudo tee /etc/sensu/uchiwa.json << EOF
|
||||
EOF
|
||||
```
|
||||
|
||||
在这个文件中，我们配置 `Uchiwa` 监听端口 3000 上的每个地址（0.0.0.0）。我们还配置 `Uchiwa` 使用 `sensu-api`（已配置好）。
|
||||
在这个文件中，我们配置 Uchiwa 监听每个地址（0.0.0.0）的端口 3000。我们还配置 Uchiwa 使用 `sensu-api`（已配置好）。
|
||||
|
||||
出于安全原因，更改刚刚创建的配置文件的所有者：
|
||||
|
||||
```
|
||||
$ sudo chown -R sensu:sensu /etc/sensu
|
||||
```
|
||||
|
||||
启用并启动 Sensu 服务：
|
||||
|
||||
```
|
||||
$ sudo systemctl enable sensu-server sensu-api sensu-client
|
||||
$ sudo systemctl start sensu-server sensu-api sensu-client
|
||||
@ -140,15 +147,16 @@ $ sudo systemctl enable uchiwa
|
||||
$ sudo systemctl start uchiwa
|
||||
```
|
||||
|
||||
尝试访问 `Uchiwa` 网站：http://<服务器的 IP 地址>:3000
|
||||
尝试访问 Uchiwa 网站：`http://<服务器的 IP 地址>:3000`
|
||||
|
||||
对于生产环境，建议运行 RabbitMQ 集群作为 Transport 而不是 Redis（虽然 Redis 集群也可以用于生产），运行多个 Sensu 服务器实例和 API 实例，以实现负载均衡和高可用性。
|
||||
对于生产环境，建议运行 RabbitMQ 集群作为 Transport 而不是 Redis（虽然 Redis 集群也可以用于生产环境），运行多个 Sensu 服务器实例和 API 实例，以实现负载均衡和高可用性。
|
||||
|
||||
Sensu 现在安装完成，让我们来配置客户端。
|
||||
|
||||
#### 客户端侧
|
||||
|
||||
要添加一个新客户端，你需要通过创建 `/etc/yum.repos.d/sensu.repo` 文件在客户机上启用 Sensu 仓库。
|
||||
|
||||
```
|
||||
$ sudo tee /etc/yum.repos.d/sensu.repo << EOF
|
||||
[sensu]
|
||||
@ -160,11 +168,13 @@ EOF
|
||||
```
|
||||
|
||||
启用仓库后，安装 Sensu：
|
||||
|
||||
```
|
||||
$ sudo yum install sensu -y
|
||||
```
|
||||
|
||||
要配置 `sensu-client`，创建在服务器中相同的 `redis.json` 和 `transport.json`，还有 `client.json` 配置文件：
|
||||
|
||||
```
|
||||
$ sudo tee /etc/sensu/conf.d/client.json << EOF
|
||||
{
|
||||
@ -179,9 +189,10 @@ $ sudo tee /etc/sensu/conf.d/client.json << EOF
|
||||
EOF
|
||||
```
|
||||
|
||||
在 `name` 字段中，指定一个名称来标识此客户机（通常是主机名）。`environment` 字段可以帮助你过滤，订阅定义客户机将执行哪些监视检查。
|
||||
在 `name` 字段中，指定一个名称来标识此客户机（通常是主机名）。`environment` 字段可以帮助你过滤，而 `subscriptions` 定义了客户机将执行哪些监视检查。
|
||||
|
||||
最后，启用并启动服务并签入 Uchiwa，因为客户机会自动注册：
|
||||
|
||||
最后，启用并启动服务并检查 `Uchiwa`，因为客户机会自动注册：
|
||||
```
|
||||
$ sudo systemctl enable sensu-client
|
||||
$ sudo systemctl start sensu-client
|
||||
@ -191,21 +202,23 @@ $ sudo systemctl start sensu-client
|
||||
|
||||
Sensu 检查有两个组件：一个插件和一个定义。
|
||||
|
||||
Sensu 与 [Nagios 检查插件规范][12]兼容，因此无需修改即可使用针对 Nagios 的任何检查。检查是可执行文件，由 Sensu 客户机运行。
|
||||
Sensu 与 [Nagios 检查插件规范][12]兼容，因此无需修改即可使用用于 Nagios 的任何检查。检查是可执行文件，由 Sensu 客户机运行。
|
||||
|
||||
检查定义让 Sensu 知道如何、在哪以及何时运行插件。
|
||||
检查定义可以让 Sensu 知道如何、在哪以及何时运行插件。
|
||||
|
||||
#### 客户端侧
|
||||
|
||||
让我们在客户机上安装一个检查插件。请记住，此插件将在客户机上执行。
|
||||
|
||||
启用 EPEL 并安装 `nagios-plugins-http` :
|
||||
启用 EPEL 并安装 `nagios-plugins-http`：
|
||||
|
||||
```
|
||||
$ sudo yum install -y epel-release
|
||||
$ sudo yum install -y nagios-plugins-http
|
||||
```
|
||||
|
||||
现在让我们通过手动执行它来研究这个插件。尝试检查客户机上运行的 Web 服务器的状态。它应该会失败，因为我们并没有运行 Web 服务器：
|
||||
现在让我们通过手动执行它来了解这个插件。尝试检查客户机上运行的 Web 服务器的状态。它应该会失败，因为我们并没有运行 Web 服务器：
|
||||
|
||||
```
|
||||
$ /usr/lib64/nagios/plugins/check_http -I 127.0.0.1
|
||||
connect to address 127.0.0.1 and port 80: Connection refused
|
||||
@ -213,26 +226,27 @@ HTTP CRITICAL - Unable to open TCP socket
|
||||
```
|
||||
|
||||
不出所料，它失败了。检查执行的返回值：
|
||||
|
||||
```
|
||||
$ echo $?
|
||||
2
|
||||
|
||||
```
|
||||
|
||||
Nagios 检查插件规范定义了插件执行的四个返回值：
|
||||
|
||||
| **Plugin return code** | **State** |
|
||||
|------------------------|-----------|
|
||||
| 0 | OK |
|
||||
| 1 | WARNING |
|
||||
| 2 | CRITICAL |
|
||||
| 3 | UNKNOWN |
|
||||
| 插件返回码 | 状态 |
|
||||
|----------|-----------|
|
||||
| 0 | OK |
|
||||
| 1 | WARNING |
|
||||
| 2 | CRITICAL |
|
||||
| 3 | UNKNOWN |
|
||||
|
||||
有了这些信息，我们现在可以在服务器上创建检查定义。
|
||||
|
||||
#### 服务器侧
|
||||
|
||||
在服务器机器上，创建 `/etc/sensu/conf.d/check_http.json` 文件：
|
||||
|
||||
```
|
||||
{
|
||||
"checks": {
|
||||
@ -247,9 +261,9 @@ Nagios 检查插件规范定义了插件执行的四个返回值：
|
||||
}
|
||||
```
|
||||
|
||||
在 `command ` 字段中，使用我们之前测试过的命令。`Interval` 会告诉 Sensu 这个检查的频率，以秒为单位。最后，`subscribers` 将定义执行检查的客户机。
|
||||
在 `command` 字段中，使用我们之前测试过的命令。`interval` 会告诉 Sensu 这个检查的频率，以秒为单位。最后，`subscribers` 将定义执行检查的客户机。
|
||||
|
||||
重新启动 sensu-api 和 sensu-server 并确认新检查在 Uchiwa 中可用。
|
||||
重新启动 `sensu-api` 和 `sensu-server` 并确认新检查在 Uchiwa 中可用。
|
||||
|
||||
```
|
||||
$ sudo systemctl restart sensu-api sensu-server
|
||||
@ -265,8 +279,8 @@ via: https://opensource.com/article/18/8/getting-started-sensu-monitoring-soluti
|
||||
|
||||
作者：[Michael Zamot][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
译者：[MjSeven](https://github.com/MjSeven)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@ -0,0 +1,201 @@
|
||||
Linux 初学者：移动文件
|
||||
=====================
|
||||
|
||||
|
||||
|
||||
在之前的该系列的部分中，[你学习了有关目录][1]和[访问目录][2][的权限][7]是如何工作的。你在这些文章中学习的大多数内容都可应用于文件，除了如何让一个文件变成可执行文件。
|
||||
|
||||
因此让我们在开始之前先解决这个问题。
|
||||
|
||||
### 不需要 .exe 扩展名
|
||||
|
||||
在其他操作系统中，一个文件的性质通常由它的后缀决定。如果一个文件有一个 .jpg 扩展，操作系统会认为它是一幅图像；如果它以 .wav 结尾，它是一个音频文件；如果它在文件名末尾以 .exe 结尾，它就是一个你可以执行的程序。
|
||||
|
||||
这导致了严重的问题，比如说木马可以伪装成文档文件。幸运的是，在 Linux 下事物不是这样运行的。可以确定的是，你可能会看到有些可执行文件是以 .sh 结尾暗示它们是可执行的脚本，但是这大部分是为了便于人眼找到文件，就像你使用 `ls --color` 将可执行文件的名字以亮绿色显示的方式相同。
|
||||
|
||||
事实上大多数应用根本没有扩展名。决定一个文件是否是一个真正程序的是 `x` （指*可执行的*）位。你可以通过运行以下命令使任何文件变得可执行，
|
||||
|
||||
```
|
||||
chmod a+x some_program
|
||||
```
|
||||
|
||||
而不管它的扩展名是什么或者是否存在。在上面命令中的 `x` 设置了 `x` 位，`a` 说明你为*所有*用户设置它。你同样可以为一组用户设置成拥有这个文件（`g+x`），或者只为一个用户——拥有者——设置 （`u+x`）。
|
||||
|
||||
尽管我们会在该系列之后的部分包含从命令行创建和运行脚本的内容，并学习通过输入它的路径并在结尾加上程序名的方式运行一个程序：
|
||||
|
||||
```
|
||||
path/to/directory/some_program
|
||||
```
|
||||
|
||||
或者，如果你当前在相同目录，你可以使用：
|
||||
|
||||
```
|
||||
./some_program
|
||||
```
|
||||
|
||||
还有其他方式可以使你的程序在目录树的任意位置运行 （提示：查询 `$PATH` 环境变量），但是当我们讨论 shell 脚本的时候你会读到这些。
|
||||
|
||||
### 复制、移动、链接
|
||||
|
||||
明显地，从命令行修改和处理文件有很多的方式，而不仅仅是处理它们的权限。当你试图打开一个不存在的文件是，大多数应用会创建一个新文件。如果 `test.txt` 当前并不存在，下列命令：
|
||||
|
||||
```
|
||||
nano test.txt
|
||||
```
|
||||
|
||||
```
|
||||
vim test.txt
|
||||
```
|
||||
|
||||
（[nano][3] 和 [vim][4] 是流行的命令行文本编辑器）都将为你创建一个空的 `test.txt` 文件来编辑。
|
||||
|
||||
你可以通过 “触摸” （`touch`）来创建一个空的文件，
|
||||
|
||||
```
|
||||
touch test.txt
|
||||
```
|
||||
|
||||
会创建一个文件，但是不会在任何应用中打开它。
|
||||
|
||||
你可以使用 `cp` 来拷贝一个文件到另一个位置，或者使用一个不同的名字：
|
||||
|
||||
```
|
||||
cp test.txt copy_of_test.txt
|
||||
```
|
||||
|
||||
你也可以拷贝一堆文件：
|
||||
|
||||
```
|
||||
cp *.png /home/images
|
||||
```
|
||||
|
||||
上面的命令拷贝当前目录下的所有 PNG 文件到相对你的主目录下的 `images/` 目录。在你尝试之前 `images/` 目录必须存在， 不然 `cp` 将显示一个错误。同样的，警惕，当你复制一个文件到一个已经包含相同名字的文件的目录时，`cp` 会静默地用新文件覆盖老的文件。
|
||||
|
||||
你可以使用：
|
||||
|
||||
```
|
||||
cp -i *.png /home/images
|
||||
```
|
||||
|
||||
如果你想要 `cp` 命令在有任何危险时警告你 （`-i` 选项代表*交互式的*）。
|
||||
|
||||
你同样可以复制整个目录，但是为了做到这样，你需要 `-r` 选项：
|
||||
|
||||
```
|
||||
cp -rv directory_a/ directory_b
|
||||
```
|
||||
|
||||
`-r` 选项代表*递归*，意味着 `cp` 会向下探索目录 `directory_a`，复制所有的文件和子目录下内部包含的。我个人喜欢包含 `-v` 选项，因为它使 `cp` 冗长而啰嗦，意味着它会显示你当前它正在做什么而不是仅仅静默的复制然后存在。
|
||||
|
||||
`mv` 命令移动东西。也就是说，它移动文件从一个位置到另一个位置。最简单的形式，`mv` 表现的更像 `cp`：
|
||||
|
||||
```
|
||||
mv test.txt new_test.txt
|
||||
```
|
||||
|
||||
上面的命令使 `new_test.txt` 出现，`test.txt` 消失。
|
||||
|
||||
```
|
||||
mv *.png /home/images
|
||||
```
|
||||
|
||||
移动当前目录下所有的 PNG 文件到相对于你的主目录的 `images/` 目录。同样的你必须小心你没有意外的覆盖已存在的文件。使用
|
||||
|
||||
```
|
||||
mv -i *.png /home/images
|
||||
|
||||
```
|
||||
|
||||
如果你想站在安全的角度，你可以使用与 `cp` 相同的方式。
|
||||
|
||||
除了移动与拷贝的不同外，另一个 `mv` 和 `cp` 之间的不同是当你移动目录时：
|
||||
|
||||
```
|
||||
mv directory_a/ directory_b
|
||||
```
|
||||
|
||||
不需要添加递归的标志。这是因为你实际做的是重命名一个目录，与第一个例子相同，你做的是重命名文件。实际上，即使你从一个目录到另一个目录 “移动” 一个文件，只要两个目录在相同的存储设备和分区，你就是在重命名文件。
|
||||
|
||||
你可以做一个实验来证明。 `time` 是一个工具来让你测量一个命令花费多久来执行。找一个非常大的文件，可以是几百 MB 甚至 几 GB （例如一个长视频），像下方这样尝试拷贝到另一个目录：
|
||||
|
||||
```
|
||||
$ time cp hefty_file.mkv another_directory/
|
||||
real 0m3,868s
|
||||
user 0m0,016s
|
||||
sys 0m0,887s
|
||||
```
|
||||
|
||||
下面是 `time` 的输出。需要关注的是第一行， real 时间。它花费了几乎 4 秒来拷贝 355 MB 的 `hefty_file.mkv` 到 `another_directory/` 目录。
|
||||
|
||||
现在让我们尝试移动它：
|
||||
|
||||
```
|
||||
$ time mv hefty_file.mkv another_directory/
|
||||
real 0m0,004s
|
||||
user 0m0,000s
|
||||
sys 0m0,003s
|
||||
```
|
||||
|
||||
移动几乎是瞬时的！这是违反直觉的，因为看起来 `mv` 必须复制这个文件然后删除原来的。这是 `mv` 对比 `cp` 命令必须做的两件事。但是，实际上，`mv` 快了 1000 倍。
|
||||
|
||||
这是因为文件系统结构中，它的所有目录树，只为了让用户便利而存在。在每个分区的开始，有一个称作*分区表*的东西告诉操作系统在实际的物理磁盘上去哪找每个文件。在磁盘上，数据没有分为目录甚至是文件。[作为替代的是轨道、扇区和簇][5]。当你在相同分区 “移动” 一个文件时，操作系统实际做的仅仅是在分区表中改变了那个文件的入口，但它仍然指向磁盘上相同的簇信息。
|
||||
|
||||
是的！移动是一个谎言！至少在相同分区下是。如果你试图移动一个文件到一个不同的分区或者不同的设备， `mv` 仍然很快，但可以察觉到它比在相同分区下移动文件慢了。这是因为实际上发生了复制和清除数据。
|
||||
|
||||
### 重命名
|
||||
|
||||
有几个不同的命令行 `rename` 工具。没有一个像 `cp` 和 `mv` 那样固定，并且它们工作的方式都有一点不同，相同的一点是它们都被用来改变文件名的部分。
|
||||
|
||||
在 Debian 和 Ubuntu 中， 默认的 `rename` 工具使用 [正则表达式][6]（字符组成的字符串模式）来大量的改变目录中的文件。命令：
|
||||
|
||||
```
|
||||
rename 's/\.JPEG$/.jpg/' *
|
||||
```
|
||||
|
||||
将改变所有扩展名为 `JPEG` 的文件为 `jpg`。文件 `IMG001.JPEG` 变成 `IMG001.jpg`、 `my_pic.JPEG` 变成 `my_pic.jpg`，等等。
|
||||
|
||||
另一个 `rename` 版本默认在 Manjaro 上可获得，这是一个 Arch 的衍生版，更简单，但是可能没有那么强大：
|
||||
|
||||
```
|
||||
rename .JPEG .jpg *
|
||||
```
|
||||
|
||||
这和你之前看到的上面做相同的重命名操作。在这个版本，`.JPEG` 是你想改变的字符组成的字符串，`.jpg` 是你想要改变成为的，`*` 表示当前目录下的所有文件。
|
||||
|
||||
基本原则是如果你所做的仅仅是重命名一个文件或者目录，你最好用 `mv`，这是因为 `mv` 在所有分发版上都是可靠一致的。
|
||||
|
||||
### 了解更多
|
||||
|
||||
查看 `mv` 和 `cp` 的 man 页面了解更多。运行
|
||||
|
||||
```
|
||||
man cp
|
||||
```
|
||||
|
||||
或者
|
||||
```
|
||||
man mv
|
||||
```
|
||||
|
||||
来阅读这些命令自带的所有选项，这些使他们使用起来更强大和安全。
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/2018/8/linux-beginners-moving-things-around
|
||||
|
||||
作者：[Paul Brown][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.linux.com/users/bro66
|
||||
[1]: https://linux.cn/article-10066-1.html
|
||||
[2]: https://linux.cn/article-10399-1.html
|
||||
[3]: https://www.nano-editor.org/
|
||||
[4]: https://www.vim.org/
|
||||
[5]: https://en.wikipedia.org/wiki/Disk_sector
|
||||
[6]: https://en.wikipedia.org/wiki/Regular_expression
|
||||
[7]: https://linux.cn/article-10370-1.html
|
||||
|
||||
@ -0,0 +1,236 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10789-1.html)
|
||||
[#]: subject: (How to Install MySQL in Ubuntu Linux)
|
||||
[#]: via: (https://itsfoss.com/install-mysql-ubuntu/)
|
||||
[#]: author: (Sergiu https://itsfoss.com/author/sergiu/)
|
||||
|
||||
怎样在 Ubuntu Linux 上安装 MySQL
|
||||
======
|
||||
|
||||
> 本教程教你如何在基于 Ubuntu 的 Linux 发行版上安装 MySQL。对于首次使用的用户，你将会学习到如何验证你的安装和第一次怎样去连接 MySQL。
|
||||
|
||||
[MySQL][1] 是一个典型的数据库管理系统。它被用于许多技术栈中，包括流行的 [LAMP][2] （Linux、Apache、MySQL、PHP）技术栈。它已经被证实了其稳定性。另一个让 MySQL 受欢迎的原因是它是开源的。
|
||||
|
||||
MySQL 是关系型数据库（基本上是表格数据）。以这种方式它很容易去存储、组织和访问数据。它使用SQL（结构化查询语言）来管理数据。
|
||||
|
||||
这这篇文章中，我将向你展示如何在 Ubuntu 18.04 安装和使用 MySQL 8.0。让我们一起来看看吧！
|
||||
|
||||
### 在 Ubuntu 上安装 MySQL
|
||||
|
||||
![][3]
|
||||
|
||||
我将会介绍两种在 Ubuntu 18.04 上安装 MySQL 的方法：
|
||||
|
||||
1. 从 Ubuntu 仓库上安装 MySQL。非常简单，但不是最新版（5.7）
|
||||
2. 从官方仓库安装 MySQL。你将额外增加一些步处理过程，但不用担心。你将会拥有最新版的MySQL（8.0）
|
||||
|
||||
有必要的时候，我将会提供屏幕截图去引导你。但这篇文章中的大部分步骤，我将直接在终端（默认热键： `CTRL+ALT+T`）输入命令。别害怕！
|
||||
|
||||
#### 方法 1、从 Ubuntu 仓库安装 MySQL
|
||||
|
||||
首先，输入下列命令确保你的仓库已经被更新：
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
```
|
||||
|
||||
现在，安装 MySQL 5.7，简单输入下列命令：
|
||||
|
||||
```
|
||||
sudo apt install mysql-server -y
|
||||
```
|
||||
|
||||
就是这样！简单且高效。
|
||||
|
||||
#### 方法 2、使用官方仓库安装 MySQL
|
||||
|
||||
虽然这个方法多了一些步骤，但我将逐一介绍，并尝试写下清晰的笔记。
|
||||
|
||||
首先浏览 MySQL 官方网站的[下载页面][4]。
|
||||
|
||||
![][5]
|
||||
|
||||
在这里，选择 DEB 软件包，点击“Download”链接。
|
||||
|
||||
![][6]
|
||||
|
||||
滑到有关于 Oracle 网站信息的底部，右键 “No thanks, just start my download.”，然后选择 “Copy link location”。
|
||||
|
||||
现在回到终端，我们将使用 [Curl][7] 命令去下载这个软件包：
|
||||
|
||||
```
|
||||
curl -OL https://dev.mysql.com/get/mysql-apt-config_0.8.12-1_all.deb
|
||||
```
|
||||
|
||||
`https://dev.mysql.com/get/mysql-apt-config_0.8.12-1_all.deb` 是我刚刚从网页上复制的链接。根据当前的 MySQL 版本，它有可能不同。让我们使用 `dpkg` 去开始安装 MySQL：
|
||||
|
||||
```
|
||||
sudo dpkg -i mysql-apt-config*
|
||||
```
|
||||
|
||||
更新你的仓库：
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
```
|
||||
|
||||
要实际安装 MySQL，我们将使用像第一个方法中同样的命令来安装：
|
||||
|
||||
```
|
||||
sudo apt install mysql-server -y
|
||||
```
|
||||
|
||||
这样做会在你的终端中打开包配置的提示。使用向下箭头选择“Ok”选项。
|
||||
|
||||
![][8]
|
||||
|
||||
点击回车。这应该会提示你输入密码：这是在为 MySQL 设置 root 密码。不要与 [Ubuntu 的 root 密码混淆][9]。
|
||||
|
||||
![][10]
|
||||
|
||||
输入密码然后点击 Tab 键去选择“Ok“。点击回车键，你将重新输入密码。操作完之后，再次键入 Tab 去选择 “Ok”。按下回车键。
|
||||
|
||||
![][11]
|
||||
|
||||
将会展示一些关于 MySQL Server 的配置信息。再次按下 Tab 去选择 “Ok” 和按下回车键：
|
||||
|
||||
![][12]
|
||||
|
||||
这里你需要去选择默认验证插件。确保选择了“Use Strong Password Encryption”。按下 Tab 键和回车键。
|
||||
|
||||
就是这样！你已经成功地安装了 MySQL。
|
||||
|
||||
#### 验证你的 MySQL 安装
|
||||
|
||||
要验证 MySQL 已经正确安装，使用下列命令：
|
||||
|
||||
```
|
||||
sudo systemctl status mysql.service
|
||||
```
|
||||
|
||||
这将展示一些关于 MySQL 服务的信息：
|
||||
|
||||
![][13]
|
||||
|
||||
你应该在那里看到 “Active: active (running)”。如果你没有看到，使用下列命令去开始这个服务：
|
||||
|
||||
```
|
||||
sudo systemctl start mysql.service
|
||||
```
|
||||
|
||||
#### 配置/保护 MySQL
|
||||
|
||||
对于刚安装的 MySQL，你应该运行它提供的安全相关的更新命令。就是：
|
||||
|
||||
```
|
||||
sudo mysql_secure_installation
|
||||
```
|
||||
|
||||
这样做首先会询问你是否想使用 “<ruby>密码有效强度<rt>validate password component</rt></ruby>”。如果你想使用它，你将必须选择一个最小密码强度（0 – 低，1 – 中，2 – 高）。你将无法输入任何不遵守所选规则的密码。如果你没有使用强密码的习惯（本应该使用），这可能会配上用场。如果你认为它可能有帮助，那你就键入 `y` 或者 `Y`，按下回车键，然后为你的密码选择一个强度等级和输入一个你想使用的密码。如果成功，你将继续强化过程；否则你将重新输入一个密码。
|
||||
|
||||
但是，如果你不想要此功能（我不会），只需按回车或任何其他键即可跳过使用它。
|
||||
|
||||
对于其他选项，我建议开启它们（对于每一步输入 `y` 或者 `Y` 和按下回车）。它们（依序）是：“<ruby>移除匿名用户<rt>remove anonymous user</rt></ruby>”，“<ruby>禁止 root 远程登录<rt>disallow root login remotely</rt></ruby>”，“<ruby>移除测试数据库及其访问<rt>remove test database and access to it</rt></ruby>”。“<ruby>重新载入权限表<rt>reload privilege tables now</rt></ruby>”。
|
||||
|
||||
#### 链接与断开 MySQL Server
|
||||
|
||||
为了运行 SQL 查询，你首先必须使用 MySQL 连到服务器并在 MySQL 提示符使用。
|
||||
|
||||
执行此操作的命令是：
|
||||
|
||||
```
|
||||
mysql -h host_name -u user -p
|
||||
```
|
||||
|
||||
* `-h` 用来指定一个主机名（如果这个服务被安装到其他机器上，那么会有用；如果没有，忽略它）
|
||||
* `-u` 指定登录的用户
|
||||
* `-p` 指定你想输入的密码.
|
||||
|
||||
虽然出于安全原因不建议，但是你可以在命令行最右边的 `-p` 后直接输入密码。例如，如果用户`test_user` 的密码是 `1234`，那么你可以在你使用的机器上尝试去连接，你可以这样使用：
|
||||
|
||||
```
|
||||
mysql -u test_user -p1234
|
||||
```
|
||||
|
||||
如果你成功输入了必要的参数，你将会收到由 MySQL shell 提示符提供的欢迎（`mysql >`）：
|
||||
|
||||
![][14]
|
||||
|
||||
要从服务端断开连接和离开 MySQL 提示符，输入：
|
||||
|
||||
```
|
||||
QUIT
|
||||
```
|
||||
|
||||
输入 `quit` （MySQL 不区分大小写）或者 `\q` 也能工作。按下回车退出。
|
||||
|
||||
你使用简单的命令也能输出关于版本的信息：
|
||||
|
||||
```
|
||||
sudo mysqladmin -u root version -p
|
||||
```
|
||||
|
||||
如果你想看命令行选项列表，使用：
|
||||
|
||||
```
|
||||
mysql --help
|
||||
```
|
||||
|
||||
#### 卸载 MySQL
|
||||
|
||||
如果您决定要使用较新版本或只是想停止使用 MySQL。
|
||||
|
||||
首先，关闭服务：
|
||||
|
||||
```
|
||||
sudo systemctl stop mysql.service && sudo systemctl disable mysql.service
|
||||
```
|
||||
|
||||
确保你备份了你的数据库，以防你之后想使用它们。你可以通过运行下列命令卸载 MySQL：
|
||||
|
||||
```
|
||||
sudo apt purge mysql*
|
||||
```
|
||||
|
||||
清理依赖：
|
||||
|
||||
```
|
||||
sudo apt autoremove
|
||||
```
|
||||
|
||||
### 小结
|
||||
|
||||
在这篇文章中，我已经介绍如何在 Ubuntu Linux 上安装 Mysql。我很高兴如果这篇文章能帮助到那些正为此挣扎的用户或者刚刚开始的用户。
|
||||
|
||||
如果你发现这篇文章是一个很有用的资源，在评论里告诉我们。你为了什么使用 MySQL? 我们渴望收到你的任何反馈、印象和建议。感谢阅读，并毫不犹豫地尝试这个很棒的工具！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/install-mysql-ubuntu/
|
||||
|
||||
作者：[Sergiu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[arrowfeng](https://github.com/arrowfeng)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/sergiu/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.mysql.com/
|
||||
[2]: https://en.wikipedia.org/wiki/LAMP_(software_bundle)
|
||||
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/install-mysql-ubuntu.png?resize=800%2C450&ssl=1
|
||||
[4]: https://dev.mysql.com/downloads/repo/apt/
|
||||
[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_apt_download_page.jpg?fit=800%2C280&ssl=1
|
||||
[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_deb_download_link.jpg?fit=800%2C507&ssl=1
|
||||
[7]: https://linuxhandbook.com/curl-command-examples/
|
||||
[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_package_configuration_ok.jpg?fit=800%2C587&ssl=1
|
||||
[9]: https://itsfoss.com/change-password-ubuntu/
|
||||
[10]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_enter_password.jpg?fit=800%2C583&ssl=1
|
||||
[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_information_on_configuring.jpg?fit=800%2C581&ssl=1
|
||||
[12]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_default_authentication_plugin.jpg?fit=800%2C586&ssl=1
|
||||
[13]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_service_information.jpg?fit=800%2C402&ssl=1
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_shell_prompt-2.jpg?fit=800%2C423&ssl=1
|
||||
@ -0,0 +1,69 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10797-1.html)
|
||||
[#]: subject: (Most data center workers happy with their jobs -- despite the heavy demands)
|
||||
[#]: via: (https://www.networkworld.com/article/3389359/most-data-center-workers-happy-with-their-jobs-despite-the-heavy-demands.html#tk.rss_all)
|
||||
[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
|
||||
|
||||
许多数据中心的工作者很满意他们的工作，将鼓励他们的孩子继续从事这份工作
|
||||
======
|
||||
|
||||
> 一份 Informa Engage 和 Data Center Knowledge 的报告调查发现，在数据中心工作的人很满意他们的工作，因此他们将会鼓励他们的孩子从事这份工作。
|
||||
|
||||
![Thinkstock][1]
|
||||
|
||||
一份由 [Informa Engage 和 Data Center Knowledge][2] 主导的调查报告显示，数据中心的工作者总体上对他们的工作很满意。尽管对时间和大脑的要求很高，但是他们还是鼓励自己的孩子能从事这项工作。
|
||||
|
||||
总体满意度非常好，72％ 的受访者普遍同意“我喜欢我目前的工作”这一说法，三分之一的受访者则表示非常同意。75％ 的人同意声明，“如果我的孩子、侄女或侄子问，我将建议他们进入 IT 行业。”
|
||||
|
||||
在数据中心工作的员工之中，有一种很重要的感觉，88% 的人觉得他们自己对于雇主的成功非常重要。
|
||||
|
||||
尽管存在一些挑战，其中最主要的是技能和认证的缺乏。调查的受访者认为缺乏技能是最受关注的领域。只有 56％ 的人认为他们需要完成工作所需的培训，74％ 的人表示他们已经在 IT 行业工作了十多年。
|
||||
|
||||
这个行业提供认证计划，每个主要的 IT 硬件供应商都有，但是 61% 的人表示在过去的 12 个月里他们并没有完成或者重新续订证书。有几个原因：
|
||||
|
||||
三分之一（34%）说是由于他们工作的组织缺乏培训预算，而 24% 的人认为是缺乏时间，16% 的人表示管理者认为不需要培训，以及另外 16% 的人表示在他们的工作地点没有培训计划。
|
||||
|
||||
这并不让我感到惊讶，因为科技是世界上最开放的行业之一，在那里你可以找到培训和教育材料并自学。已经证实了[许多程序员是自学成才][4]，包括行业巨头比尔·盖茨、史蒂夫·沃兹尼亚克、约翰·卡马克和杰克·多尔西。
|
||||
|
||||
### 数据中心工作者们的薪水
|
||||
|
||||
数据中心工作者不会抱怨酬劳。当然，大部分不会。50% 的人每年可以赚到 $100,000 甚至更多，然而 11% 的人赚的少于 $40,000。三分之二的受访者来自于美国，因此那些低端收入人士可能在国外。
|
||||
|
||||
有一个值得注意的差异。史蒂夫·布朗是伦敦数据中心人力资源的总经理，他说软件工程师获得的薪水比硬件工程师多。
|
||||
|
||||
布朗在这篇报道中说，“数据中心软件工程方面的工作可以与高收入的职业媲美，而在物理基础设施——机械/电气方面的工作——情况并非如此。它更像是中层管理。”
|
||||
|
||||
### 数据中心的专业人士仍然主要是男性
|
||||
|
||||
最不令人惊讶的发现？10 个受访者中有 9 个是男性。该行业正在调整解决性别歧视问题，但是现在没什么改变。
|
||||
|
||||
这篇报告的结论有一点不太好，但是我认为是错的：
|
||||
|
||||
> “随着数据中心基础设施完成云计算模式的过渡，软件进入到容器和微服务时代，数据中心剩下来的珍贵领导者——在 20 世纪获得技能的人——可能会发现没有任何他们了解的东西需要管理，也没有人需要他们领导。当危机最终来临时，我们可能会感到震惊，但是我们不能说我们没有受到警告。"
|
||||
|
||||
我说过了很多次，[数据中心不会消失][6]。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3389359/most-data-center-workers-happy-with-their-jobs-despite-the-heavy-demands.html
|
||||
|
||||
作者：[Andy Patrizio][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[arrowfeng](https://github.com/arrowfeng)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Andy-Patrizio/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://images.idgesg.net/images/article/2018/02/data_center_thinkstock_879720438-100749725-large.jpg
|
||||
[2]: https://informa.tradepub.com/c/pubRD.mpl?sr=oc&_t=oc:&qf=w_dats04&ch=datacenterkids
|
||||
[3]: https://www.networkworld.com/article/3276025/20-hot-jobs-ambitious-it-pros-should-shoot-for.html
|
||||
[4]: https://www.networkworld.com/article/3046178/survey-finds-most-coders-are-self-taught.html
|
||||
[5]: https://pluralsight.pxf.io/c/321564/424552/7490?u=https%3A%2F%2Fwww.pluralsight.com%2Fpaths%2Fupgrading-your-technology-career
|
||||
[6]: https://www.networkworld.com/article/3289509/two-studies-show-the-data-center-is-thriving-instead-of-dying.html
|
||||
[7]: https://www.facebook.com/NetworkWorld/
|
||||
[8]: https://www.linkedin.com/company/network-world
|
||||
@ -0,0 +1,105 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10795-1.html)
|
||||
[#]: subject: (Ubuntu 19.04 ‘Disco Dingo’ Has Arrived: Downloads Available Now!)
|
||||
[#]: via: (https://itsfoss.com/ubuntu-19-04-release/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
下载安装 Ubuntu 19.04 “Disco Dingo”
|
||||
======
|
||||
|
||||
Ubuntu 19.04 “Disco Dingo” 已经发布，可以下载了。虽然我们已经知道 [Ubuntu 19.04 中的新功能][1] —— 我将在下面提到一些重要的地方，还会给出官方的下载链接。
|
||||
|
||||
### Ubuntu 19.04：你需要知道什么
|
||||
|
||||
以下是你应该了解的有关 Ubuntu 19.04 Disco Dingo 发布的一些内容。
|
||||
|
||||
#### Ubuntu 19.04 不是 LTS 版本
|
||||
|
||||
与 Ubuntu 18.04 LTS 不同，它不会[支持 10 年][2]。相反，非 LTS 的 19.04 将支持 **9 个月，直到 2020 年 1 月。**
|
||||
|
||||
因此，如果你有生产环境，我们可能不会立即建议你进行升级。例如，如果你有一台运行在 Ubuntu 18.04 LTS 上的服务器 —— 只是因为它是一个新的版本就将它升级到 19.04 可能不是一个好主意。
|
||||
|
||||
但是，对于希望在计算机上安装最新版本的用户，可以尝试一下。
|
||||
|
||||
![][3]
|
||||
|
||||
#### Ubuntu 19.04 对 NVIDIA GPU 用户是个不错的更新
|
||||
|
||||
Martin Wimpress（来自 Canonical）在 Ubuntu MATE 19.04（Ubuntu 版本之一）的 [GitHub][4] 的最终发布说明中提到 Ubuntu 19.04 对 NVIDIA GPU 用户来说特别重要。
|
||||
|
||||
换句话说，在安装专有图形驱动时 —— 它现在会选择与你特定 GPU 型号兼容最佳的驱动程序。
|
||||
|
||||
#### Ubuntu 19.04 功能
|
||||
|
||||
- https://youtu.be/sbbPYdpdMb8
|
||||
|
||||
尽管我们已经讨论过 [Ubuntu 19.04][1] Disco Dingo 的[最佳功能][1]，但值得一提的是，我对本次发布的主要变化：桌面更新 （GNOME 3.32） 和 Linux 内核 （5.0）感到兴奋。
|
||||
|
||||
#### 从 Ubuntu 18.10 升级到 19.04
|
||||
|
||||
显而易见，如果你安装了 Ubuntu 18.10，你应该升级它。18.10 将于 2019 年 7 月停止支持 —— 所以我们建议你将其升级到 19.04。
|
||||
|
||||
要做到这一点，你可以直接进入“软件和更新”设置，然后选择“更新”选项卡。
|
||||
|
||||
现在将选项从“通知我新的 Ubuntu 版本” 变成 “任何新版本都通知我”。
|
||||
|
||||
现在再次运行更新管理器时，你应该会看到 Ubuntu 19.04。
|
||||
|
||||
![][5]
|
||||
|
||||
#### 从 Ubuntu 18.04 升级到 19.04
|
||||
|
||||
建议不要直接从 18.04 升级到 19.04，因为你需要先将操作系统更新到 18.10，然后再继续升级到 19.04。
|
||||
|
||||
相反，你只需下载 Ubuntu 19.04 的官方 ISO 映像，然后在你的系统上重新安装 Ubuntu。
|
||||
|
||||
### Ubuntu 19.04：所有版本都可下载
|
||||
|
||||
根据[发行说明][6]，现在可以下载 Ubuntu 19.04。你可以在其官方发布下载页面上获取种子或 ISO 文件。
|
||||
|
||||
- [下载 Ubuntu 19.04][7]
|
||||
|
||||
如果你需要不同的桌面环境或需要特定的东西，你应该查看 Ubuntu 的官方版本：
|
||||
|
||||
* [Ubuntu MATE][8]
|
||||
* [Kubuntu][9]
|
||||
* [Lubuntu][10]
|
||||
* [Ubuntu Budgie][11]
|
||||
* [Ubuntu Studio][12]
|
||||
* [Xubuntu][13]
|
||||
|
||||
上面提到的一些 Ubuntu 版本还没有在页面提供 19.04。但你可以[仍然在 Ubuntu 的发行说明网页上找到 ISO][6]。就个人而言，我使用带 GNOME 桌面的 Ubuntu。你可以选择你喜欢的。
|
||||
|
||||
### 总结
|
||||
|
||||
你如何看待 Ubuntu 19.04 Disco Dingo？这些新功能是否足够令人兴奋？你试过了吗？请在下面的评论中告诉我们。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/ubuntu-19-04-release/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://itsfoss.com/ubuntu-19-04-release-features/
|
||||
[2]: https://itsfoss.com/ubuntu-18-04-ten-year-support/
|
||||
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2018/11/ubuntu-19-04-Disco-Dingo-default-wallpaper.jpg?resize=800%2C450&ssl=1
|
||||
[4]: https://github.com/ubuntu-mate/ubuntu-mate.org/blob/master/blog/20190418-ubuntu-mate-disco-final-release.md
|
||||
[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/ubuntu-19-04-upgrade-available.jpg?ssl=1
|
||||
[6]: https://wiki.ubuntu.com/DiscoDingo/ReleaseNotes
|
||||
[7]: https://www.ubuntu.com/download/desktop
|
||||
[8]: https://ubuntu-mate.org/download/
|
||||
[9]: https://kubuntu.org/getkubuntu/
|
||||
[10]: https://lubuntu.me/cosmic-released/
|
||||
[11]: https://ubuntubudgie.org/downloads
|
||||
[12]: https://ubuntustudio.org/2019/04/ubuntu-studio-19-04-released/
|
||||
[13]: https://xubuntu.org/download/
|
||||
@ -1,13 +1,13 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10787-1.html)
|
||||
[#]: subject: (4 cool new projects to try in COPR for April 2019)
|
||||
[#]: via: (https://fedoramagazine.org/4-cool-new-projects-to-try-in-copr-for-april-2019/)
|
||||
[#]: author: (Dominik Turecek https://fedoramagazine.org/author/dturecek/)
|
||||
|
||||
2019 年 4 月在 COPR 值得尝试的 4 个很酷的新项目
|
||||
COPR 仓库中 4 个很酷的新软件（2019.4）
|
||||
======
|
||||
|
||||
![][1]
|
||||
@ -18,13 +18,13 @@ COPR 是个人软件仓库[集合][1]，它不在 Fedora 中。这是因为某
|
||||
|
||||
### Joplin
|
||||
|
||||
[Joplin][3] 是一个笔记和待办事项应用。笔记以 Markdown 格式编写，并通过将它们分类到各种笔记本中并使用标签进行组织。Joplin 可以从任何 Markdown 源导入笔记或从 Evernote 导出笔记。除了桌面应用之外，还有一个 Android 版本，通过使用 Nextcloud、Dropbox 或其他云服务同步笔记。最后，它还有 Chrome 和 Firefox 的浏览器扩展程序，用于保存网页和屏幕截图。
|
||||
[Joplin][3] 是一个笔记和待办事项应用。笔记以 Markdown 格式编写，并通过使用标签和将它们分类到各种笔记本中进行组织。Joplin 可以从任何 Markdown 源导入笔记或从 Evernote 导出笔记。除了桌面应用之外，还有一个 Android 版本，通过使用 Nextcloud、Dropbox 或其他云服务同步笔记。最后，它还有 Chrome 和 Firefox 的浏览器扩展程序，用于保存网页和屏幕截图。
|
||||
|
||||
![][4]
|
||||
|
||||
#### 安装说明
|
||||
|
||||
[仓库][5]目前为 Fedora 29 和 30 以及 EPEL 7 提供 Joplin。要安装 Joplin，请[带上 sudo][6] 使用这些命令：
|
||||
[COPR 仓库][5]目前为 Fedora 29 和 30 以及 EPEL 7 提供 Joplin。要安装 Joplin，请[带上 sudo][6] 使用这些命令：
|
||||
|
||||
```
|
||||
sudo dnf copr enable taw/joplin
|
||||
@ -33,11 +33,11 @@ sudo dnf install joplin
|
||||
|
||||
### Fzy
|
||||
|
||||
[Fzy][7] 是用于模糊字符串搜索的命令行程序。它从标准输入读取并根据最有可能的搜索结果进行排序，然后打印所选行。除了命令行，fzy 也可以在 vim 中使用。你可以在这个在线 [demo][8] 中尝试 fzy。
|
||||
[Fzy][7] 是用于模糊字符串搜索的命令行程序。它从标准输入读取并根据最有可能的搜索结果进行排序，然后打印所选行。除了命令行，`fzy` 也可以在 vim 中使用。你可以在这个在线 [demo][8] 中尝试 `fzy`。
|
||||
|
||||
#### 安装说明
|
||||
|
||||
[仓库][9]目前为 Fedora 29、30 和 Rawhide 以及其他发行版提供了 fzy。要安装 fzy，请使用以下命令：
|
||||
[COPR 仓库][9]目前为 Fedora 29、30 和 Rawhide 以及其他发行版提供了 `fzy`。要安装 `fzy`，请使用以下命令：
|
||||
|
||||
```
|
||||
sudo dnf copr enable lehrenfried/fzy
|
||||
@ -48,13 +48,11 @@ sudo dnf install fzy
|
||||
|
||||
Fondo 是一个浏览 [unsplash.com][10] 网站照片的程序。它有一个简单的界面，允许你一次查找某个主题或所有主题的图片。然后，你可以通过单击将找到的图片设置为壁纸，或者共享它。
|
||||
|
||||
* ![][11]
|
||||
|
||||
|
||||
![][11]
|
||||
|
||||
#### 安装说明
|
||||
|
||||
[仓库][12]目前为 Fedora 29、30 和 Rawhide 提供 Fondo。要安装 Fondo，请使用以下命令：
|
||||
[COPR 仓库][12]目前为 Fedora 29、30 和 Rawhide 提供 Fondo。要安装 Fondo，请使用以下命令：
|
||||
|
||||
```
|
||||
sudo dnf copr enable atim/fondo
|
||||
@ -63,15 +61,13 @@ sudo dnf install fondo
|
||||
|
||||
### YACReader
|
||||
|
||||
[YACReader][13] 是一款数字漫画阅读器，它支持许多漫画和图像格式，例如 _cbz_、_cbr_、_pdf_ 等。YACReader 会跟踪阅读进度，并可以从 [Comic Vine][14] 下载漫画信息。它还有一个 YACReader 库，用于组织和浏览你的漫画集。
|
||||
|
||||
* ![][15]
|
||||
|
||||
[YACReader][13] 是一款数字漫画阅读器，它支持许多漫画和图像格式，例如 cbz、cbr、pdf 等。YACReader 会跟踪阅读进度，并可以从 [Comic Vine][14] 下载漫画信息。它还有一个 YACReader 库，用于组织和浏览你的漫画集。
|
||||
|
||||
![][15]
|
||||
|
||||
#### 安装说明
|
||||
|
||||
[仓库][16]目前为 Fedora 29、30 和 Rawhide 提供 YACReader。要安装 YACReader，请使用以下命令：
|
||||
[COPR 仓库][16]目前为 Fedora 29、30 和 Rawhide 提供 YACReader。要安装 YACReader，请使用以下命令：
|
||||
|
||||
```
|
||||
sudo dnf copr enable atim/yacreader
|
||||
@ -85,7 +81,7 @@ via: https://fedoramagazine.org/4-cool-new-projects-to-try-in-copr-for-april-201
|
||||
作者：[Dominik Turecek][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@ -0,0 +1,147 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10790-1.html)
|
||||
[#]: subject: (New Features Coming to Debian 10 Buster Release)
|
||||
[#]: via: (https://itsfoss.com/new-features-coming-to-debian-10-buster-release/)
|
||||
[#]: author: (Shirish https://itsfoss.com/author/shirish/)
|
||||
|
||||
即将到来的 Debian 10 Buster 发布版的新特点
|
||||
=======================================
|
||||
|
||||
Debian 10 Buster 即将发布。第一个发布候选版已经发布，我们预期可以在几周内见到待最终版。
|
||||
|
||||
如果你期待对这个新的主要发布版本，让我告诉你里面有什么。
|
||||
|
||||
### Debian 10 Buster 发布计划
|
||||
|
||||
[Debian 10 Buster][1] 的发布日期并没有确定。为什么这样呢？不像其他分发版，[Debian][2] 并不基于时间发布。相反地它主要关注于修复<ruby>发布版重要 Bug<rt>release-critical bug</rt></ruby>。发布版重要 Bug 要么是严重的安全问题（[CVE][3]），要么是一些其他阻止 Debian 发布的严重问题。
|
||||
|
||||
Debian 在它的软件归档中分为三个部分，叫做 Main、contrib 和 non-free。在这三者之中，Debian 开发者和发布管理者最关心的包组成了该分发版的基石。Main 是像石头一样稳定的。因此他们要确保那里没有主要的功能或者安全问题。他们同样给予了不同的优先级，例如 Essential、Required、Important、Standard、Optional 和 Extra。更多关于此方面的知识参考后续的 Debian 文章。
|
||||
|
||||
这是必要的，因为 Debian 在很多环境中被用作服务器，人们已经变得依赖 Debian。他们同样看重升级周期是否有破环，因此他们寻找人们来测试，来查看当升级的时候是否有破坏并通知 Debian 有这样的问题。
|
||||
|
||||
这种提交方式带来的稳定性[是我喜欢 Debian 的众多原因之一][4]。
|
||||
|
||||
### Debian 10 Buster 版本的新内容
|
||||
|
||||
这里是即将到来的 Debian 主要发布版的一些视觉上和内部的改变。
|
||||
|
||||
#### 新的主题和壁纸
|
||||
|
||||
Buster 的 Debian 主题被称为 [FuturePrototype][5] 并且看起来如下图：
|
||||
|
||||
![Debian Buster FuturePrototype Theme][6]
|
||||
|
||||
#### 1、GNOME 桌面 3.30
|
||||
|
||||
Debian Stretch 版中的 GNOME 桌面在 Buster 中从 1.3.22 升级到了 1.3.30。在 GNOME 桌面发布版中新包含的一些包是 gnome-todo、tracker 替代了 tracker-gui、gstreamer1.0-packagekit 的依赖，因此可以通过自动地安装编码解码器来做播放电影之类的事。对于所有包来说一个大的改变是从 libgtk2+ 到 libgtk3+。
|
||||
|
||||
#### 2、Linux 内核 4.19.0-4
|
||||
|
||||
Debian 使用 LTS 内核版本，因此你可以期待更好的硬件支持和长达 5 年的维护和支持周期。我们已经从内核 4.9.0.3 到 4.19.0-4。
|
||||
|
||||
```
|
||||
$ uname -r
|
||||
4.19.0-4-amd64
|
||||
```
|
||||
|
||||
#### 3、OpenJDK 11.0
|
||||
|
||||
Debian 在很长时间里都是 OpenJDK 8.0。现在在 Debian Buster 里我们已经升级为 OpenJDK 11.0，并且会有一个团队维护新的版本。
|
||||
|
||||
#### 4、默认启用 AppArmor
|
||||
|
||||
在 Debian Buster 中是默认启用 [AppArmor][7] 的。这是一个好事，谨慎是系统管理员必须采取的正确策略。这仅仅是第一步，并且可能需要修复很多对用户觉得有用的脚本。
|
||||
|
||||
#### 5、Nodejs 10.15.2
|
||||
|
||||
在很长一段时间里 Debian 在仓库中都只有 Nodejs 4.8。在这个周期里 Debian 已经移到 Nodejs 10.15.2。事实上，Debian Buster 有很多 javascript 库例如 yarnpkg （一个 nmp 的替代品）等等。
|
||||
|
||||
当然，你可以从该项目仓库[在 Debian 中安装最新的 Nodejs][8]，但是从 Debian 仓库中看到更新的版本是很棒的。
|
||||
|
||||
#### 6、NFtables 替代了 iptables
|
||||
|
||||
Debian Buster 提供了 nftables 来完整地替代了 iptables，因为它有更好、更简单的语法，更好的支持双栈 ipv4/v6 防火墙等等。
|
||||
|
||||
#### 7、支持更多的 ARM 64 和 ARMHF 的单板机。
|
||||
|
||||
Debian 已经支持一些常见的新的单板机，其中最新的包括 pine64_plus、ARM64 的 pinebook、Firefly-RK3288、ARMHF 64 的 u-boot-rockchip 以及 Odroid HC1/HC2 板、SolidRun Cubox-i 双核/四核（1.5som）和 SolidRun Cubox-i 双核/四核（1.5som+emmc）板、Cubietruckplus 等。同样支持 Rock 64、Banana Pi M2 Berry、Pine A64 LTS Board、Olimex A64 Teres-1 与 Rapberry Pi 1、Zero 和 Pi 3。对于 RISC-V 系统同样支持开箱即用。
|
||||
|
||||
#### 8、Python 2 已死，Python 3 长存
|
||||
|
||||
在 2020 年 1 月 1 日，Python 2 将被 python.org 废弃。在 Debian 将所有的软件包从 Python 2.7 移到 Python 3 以后，Python 2.7 将从软件仓库中移除。这可能发生在 Buster 发布版或者将来的某个发布版，这是肯定要来临的。因此 Python 开发者被鼓励移植他们的代码库来兼容 Python 3。在写本文的时候，在 Debian Buster 中同时支持 python2 和 pythone3。
|
||||
|
||||
#### 9、Mailman 3
|
||||
|
||||
在 Debian 中终于可以使用 Mailman3 了。同时 [Mailman][10] 已经被细分成为组件。要安装整个软件栈，可以安装 mailman3-full 来获取所有组件。
|
||||
|
||||
#### 10、任意已有的 Postgresql 数据库将需要重新索引
|
||||
|
||||
由于 glibc 本地数据的更新，放入文本索引中的信息排序的方式将会改变，因为重新索引是有益的，这样在将来就不会有数据破坏发生。
|
||||
|
||||
#### 11、默认 Bash 5.0
|
||||
|
||||
你可能已经了解了 [Bash 5.0 的新特点][11]，在 Debian 中已经是该版本了。
|
||||
|
||||
#### 12、Debian 实现 /usr/merge
|
||||
|
||||
我们已经分享过一个优秀的 freedesktop [读物][12]，介绍了 `/usr/merge` 带来了什么。有一些事项需要注意。当 Debian 想要整个过渡时，可能由于未预见的情况，一些二进制文件可能并没有做这些改变。需要指出的一点是，`/var` 和 `/etc` 不会被触及，因此使用容器或者云技术的不需要考虑太多 :)。
|
||||
|
||||
#### 13、支持安全启动
|
||||
|
||||
在 Buster RC1 中，Debian 现在支持<ruby>安全启动<rt>secure-boot</rt></ruby>。这意味着打开了安全启动设置的机器应该能够轻松安装 Debian。不再需要禁止或者处理安全启动的事 :)
|
||||
|
||||
#### 14、Debian-Live 镜像的 Calameres Live-installer
|
||||
|
||||
对于 Debian Buster 的 Live 版，Debian 引入了 [Calameres 安装器][13]来替代老的 Debian-installer。Debian-installer 比 Calameres 功能更多，但对于初学者，Calameres 相对于 Debian-installer 提供了另外一种全新的安装方式。安装过程的截图：
|
||||
|
||||
![Calamares Partitioning Stage][14]
|
||||
|
||||
如图所见，在 Calamares 下安装 Debian 相当简单，只要经历 5 个步骤你就能在你的机器上安装 Debian。
|
||||
|
||||
### 下载 Debian 10 Live 镜像 （只用于测试）
|
||||
|
||||
现在还不要将它用于生产机器。可以在测试机上尝试或者一个虚拟机。
|
||||
|
||||
你可以从 Debian Live [目录][15]获取 Debian 64 位和 32 位的镜像。如果你想要 64 位的就进入 `64-bit` 目录，如果你想要 32 位的，就进入 `32-bit` 目录。
|
||||
|
||||
- [下载 Debian 10 Buster Live Images][15]
|
||||
|
||||
如果你从已存在的稳定版升级并且出现了一些问题，查看它是否在预安装的[升级报告][16]中提及了，使用 [reportbug][17] 报告你看到的问题。如果 bug 没有被报告，那么请尽可能地报告和分享更多地信息。
|
||||
|
||||
### 总结
|
||||
|
||||
当上千个包被升级时，看起来不可能一一列出。我已经列出了一些你在 Debian Buster 可以找到的一些主要的改变。你怎么看呢？
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/new-features-coming-to-debian-10-buster-release/
|
||||
|
||||
作者：[Shirish][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/shirish/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://wiki.debian.org/DebianBuster
|
||||
[2]: https://www.debian.org/
|
||||
[3]: https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures
|
||||
[4]: https://itsfoss.com/reasons-why-i-love-debian/
|
||||
[5]: https://wiki.debian.org/DebianArt/Themes/futurePrototype
|
||||
[6]: https://itsfoss.com/wp-content/uploads/2019/04/debian-buster-theme-800x450.png
|
||||
[7]: https://wiki.debian.org/AppArmor
|
||||
[8]: https://itsfoss.com/install-nodejs-ubuntu/
|
||||
[9]: https://www.python.org/dev/peps/pep-0373/
|
||||
[10]: https://www.list.org/
|
||||
[11]: https://itsfoss.com/bash-5-release/
|
||||
[12]: https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/
|
||||
[13]: https://calamares.io/about/
|
||||
[14]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/calamares-partitioning-wizard.jpg?fit=800%2C538&ssl=1
|
||||
[15]: https://cdimage.debian.org/cdimage/weekly-live-builds/
|
||||
[16]: https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=upgrade-reports;dist=unstable
|
||||
[17]: https://itsfoss.com/bug-report-debian/
|
||||
@ -0,0 +1,138 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-10800-1.html)
|
||||
[#]: subject: (Four Methods To Check The Default Gateway Or Router IP Address In Linux?)
|
||||
[#]: via: (https://www.2daygeek.com/check-find-default-gateway-or-router-ip-address-in-linux/)
|
||||
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
|
||||
|
||||
4 种在 Linux 中检查默认网关或者路由器 IP 地址的方法
|
||||
==============================================
|
||||
|
||||
你应该意识到你的默认网关是你的路由器的 IP 地址。一般这是在安装过程中由操作系统自动检测的，如果没有，你可能需要改变它。如果你的系统不能 ping 自身，那么很可能是一个网关问题，你必须修复它。在网络中，当你有多个网络适配器或路由器时，这种情况可能会发生。
|
||||
|
||||
网关是一个扮演着入口点角色的路由器，可以从一个网络传递网络数据到另一个网络。
|
||||
|
||||
下面是一些可能帮助你收集到与该话题相似的一些信息。
|
||||
|
||||
* [在 Linux 命令行检查你的公网 IP 地址的 9 种方法][1]
|
||||
* [如何在 Linux 启用和禁用网卡？][2]
|
||||
|
||||
这可以通过下面的四个命令完成。
|
||||
|
||||
* `route` 命令：被用来显示和操作 IP 路由表。
|
||||
* `ip` 命令：类似于 `ifconfig`，常用于设置静态 IP 地址、路由 & 默认网关，等等。
|
||||
* `netstat` 命令：是一个命令行工具，用来显示网络连接相关的信息（包括入站和出站的），例如路由表、伪装连接、多播成员和网络接口。
|
||||
* `routel` 命令：被用来以好看的输出格式列出路由。
|
||||
|
||||
### 1）在 Linux 中如何使用 route 命令检查默认的网关或者路由 IP 地址？
|
||||
|
||||
`route` 命令被用来显示和操作 IP 路由表。
|
||||
|
||||
它主要用于通过一个已经配置的接口给特定的主机或者网络设置静态的路由。
|
||||
|
||||
当使用 `add` 或者 `del` 选项时，`route` 修改路由表。没有这些选项，`route` 显示路由表的当前内容。
|
||||
|
||||
```
|
||||
# route
|
||||
或
|
||||
# route -n
|
||||
|
||||
Kernel IP routing table
|
||||
Destination Gateway Genmask Flags Metric Ref Use Iface
|
||||
default www.routerlogin 0.0.0.0 UG 600 0 0 wlp8s0
|
||||
192.168.1.0 0.0.0.0 255.255.255.0 U 600 0 0 wlp8s0
|
||||
```
|
||||
|
||||
### 2）如何在 Linux 中使用 ip 命令检查默认网关或者路由 IP 地址？
|
||||
|
||||
[IP 命令][3] 类似于 `ifconfig`，常用于配置静态 IP 地址、路由 & 默认网关，等等。
|
||||
|
||||
`ifconfig` 命令因为多年没有维护而被遗弃了，即使它仍然在大多数 Linux 发行版上可获得。
|
||||
|
||||
`ifconfig` 命令已经被 `ip` 命令替代了，`ip` 命令是非常强大的，只要一个命令就能执行几个网络管理任务。
|
||||
|
||||
`ip` 命令工具附带在 iproute2 包中。在主要的 Linux 发行版中都默认预装了 iproute2 。
|
||||
|
||||
如果没有，你可以在你的终端中在包管理器的帮助下通过指定 iproute2 来安装它。
|
||||
|
||||
```
|
||||
# ip r
|
||||
或
|
||||
# ip route
|
||||
或
|
||||
# ip route show
|
||||
|
||||
default via 192.168.1.1 dev wlp8s0 proto dhcp metric 600
|
||||
192.168.1.0/24 dev wlp8s0 proto kernel scope link src 192.168.1.6 metric 600
|
||||
```
|
||||
|
||||
### 3）如何在 Linux 中使用 netstat 命令检查默认网关或者路由 IP 地址？
|
||||
|
||||
`netstat` 代表 Network Statistics，是一个用来显示网络连接相关的信息（包括入站和出站）的命令行工具，例如路由表、伪装连接，多播成员和网络接口。
|
||||
|
||||
它列出所有的 tcp、udp 套接字连接和 unix 套接字连接。
|
||||
|
||||
它在网络中被用来诊断网络问题并判断网络中的流量总量来作为性能测量指标。
|
||||
|
||||
```
|
||||
# netstat -r
|
||||
|
||||
Kernel IP routing table
|
||||
Destination Gateway Genmask Flags MSS Window irtt Iface
|
||||
default www.routerlogin 0.0.0.0 UG 0 0 0 wlp8s0
|
||||
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlp8s0
|
||||
```
|
||||
|
||||
### 4）如何在 Linux 中使用 routel 命令检查默认网关或者路由 IP 地址？
|
||||
|
||||
它用来以好看的输出格式列出路由信息。这些程序是一系列你可以用来替代 iproute2 的帮助脚本（`routel` 和 `routef`）。
|
||||
|
||||
`routel` 脚本以一种被认为更容易解释并且等价于 `route` 输出列表的格式来输出路由信息。
|
||||
|
||||
如果 `routef` 脚本不加任何参数，将仅仅简单的将路由表清空。小心！这意味着删除所有的路由，让你的网络不再可用。
|
||||
|
||||
```
|
||||
# routel
|
||||
target gateway source proto scope dev tbl
|
||||
default 192.168.1.1 dhcp wlp8s0
|
||||
192.168.1.0/ 24 192.168.1.6 kernel link wlp8s0
|
||||
127.0.0.0 broadcast 127.0.0.1 kernel link lo local
|
||||
127.0.0.0/ 8 local 127.0.0.1 kernel host lo local
|
||||
127.0.0.1 local 127.0.0.1 kernel host lo local
|
||||
127.255.255.255 broadcast 127.0.0.1 kernel link lo local
|
||||
192.168.1.0 broadcast 192.168.1.6 kernel link wlp8s0 local
|
||||
192.168.1.6 local 192.168.1.6 kernel host wlp8s0 local
|
||||
192.168.1.255 broadcast 192.168.1.6 kernel link wlp8s0 local
|
||||
::1 kernel lo
|
||||
fe80::/ 64 kernel wlp8s0
|
||||
::1 local kernel lo local
|
||||
fe80::ad00:2f7e:d882:5add local kernel wlp8s0 local
|
||||
ff00::/ 8 wlp8s0 local
|
||||
```
|
||||
|
||||
如果你只想打印默认的网关那么使用下面的格式。
|
||||
|
||||
|
||||
```
|
||||
# routel | grep default
|
||||
default 192.168.1.1 dhcp wlp8s0
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.2daygeek.com/check-find-default-gateway-or-router-ip-address-in-linux/
|
||||
|
||||
作者：[Magesh Maruthamuthu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.2daygeek.com/author/magesh/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.2daygeek.com/check-find-server-public-ip-address-linux/
|
||||
[2]: https://www.2daygeek.com/enable-disable-up-down-nic-network-interface-port-linux-using-ifconfig-ifdown-ifup-ip-nmcli-nmtui/
|
||||
[3]: https://www.2daygeek.com/ip-command-configure-network-interface-usage-linux/
|
||||
@ -1,73 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Most data center workers happy with their jobs -- despite the heavy demands)
|
||||
[#]: via: (https://www.networkworld.com/article/3389359/most-data-center-workers-happy-with-their-jobs-despite-the-heavy-demands.html#tk.rss_all)
|
||||
[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
|
||||
|
||||
Most data center workers happy with their jobs -- despite the heavy demands
|
||||
======
|
||||
An Informa Engage and Data Center Knowledge survey finds data center workers are content with their jobs, so much so they would encourage their children to go into that line of work.
|
||||
![Thinkstock][1]
|
||||
|
||||
A [survey conducted by Informa Engage and Data Center Knowledge][2] finds data center workers overall are content with their job, so much so they would encourage their children to go into that line of work despite the heavy demands on time and their brain.
|
||||
|
||||
Overall satisfaction is pretty good, with 72% of respondents generally agreeing with the statement “I love my current job,” while a third strongly agreed. And 75% agreed with the statement, “If my child, niece or nephew asked, I’d recommend getting into IT.”
|
||||
|
||||
**[ Also read:[20 hot jobs ambitious IT pros should shoot for][3] ]**
|
||||
|
||||
And there is a feeling of significance among data center workers, with 88% saying they feel they are very important to the success of their employer.
|
||||
|
||||
That’s despite some challenges, not the least of which is a skills and certification shortage. Survey respondents cite a lack of skills as the biggest area of concern. Only 56% felt they had the training necessary to do their job, and 74% said they had been in the IT industry for more than a decade.
|
||||
|
||||
The industry offers certification programs, every major IT hardware provider has them, but 61% said they have not completed or renewed certificates in the past 12 months. There are several reasons why.
|
||||
|
||||
A third (34%) said it was due to a lack of a training budget at their organization, while 24% cited a lack of time, 16% said management doesn’t see a need for training, and 16% cited no training plans within their workplace.
|
||||
|
||||
That doesn’t surprise me, since tech is one of the most open industries in the world where you can find training or educational materials and teach yourself. It’s already established that [many coders are self-taught][4], including industry giants Bill Gates, Steve Wozniak, John Carmack, and Jack Dorsey.
|
||||
|
||||
**[[Looking to upgrade your career in tech? This comprehensive online course teaches you how.][5] ]**
|
||||
|
||||
### Data center workers' salaries
|
||||
|
||||
Data center workers can’t complain about the pay. Well, most can’t, as 50% make $100,000 per year or more, but 11% make less than $40,000. Two-thirds of those surveyed are in the U.S., so those on the low end might be outside the country.
|
||||
|
||||
There was one notable discrepancy. Steve Brown, managing director of London-based Datacenter People, noted that software engineers get paid a lot better than the hardware people.
|
||||
|
||||
“The software engineering side of the data center is comparable to the highest-earning professions,” Brown said in the report. “On the physical infrastructure — the mechanical/electrical side — it’s not quite the case. It’s more equivalent to mid-level management.”
|
||||
|
||||
### Data center professionals still predominantly male
|
||||
|
||||
The least surprising finding? Nine out of 10 survey respondents were male. The industry is bending over backwards to fix the gender imbalance, but so far nothing has changed.
|
||||
|
||||
The conclusion of the report is a bit ominous, but I also think is wrong:
|
||||
|
||||
> “As data center infrastructure completes its transition to a cloud computing model, and software moves into containers and microservices, the remaining, treasured leaders of the data center workforce — people who acquired their skills in the 20th century — may find themselves with nothing recognizable they can manage and no-one to lead. We may be shocked when the crisis finally hits, but we won’t be able to say we weren’t warned.”
|
||||
|
||||
How many times do I have to say it, [the data center is not going away][6].
|
||||
|
||||
Join the Network World communities on [Facebook][7] and [LinkedIn][8] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3389359/most-data-center-workers-happy-with-their-jobs-despite-the-heavy-demands.html#tk.rss_all
|
||||
|
||||
作者：[Andy Patrizio][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Andy-Patrizio/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://images.idgesg.net/images/article/2018/02/data_center_thinkstock_879720438-100749725-large.jpg
|
||||
[2]: https://informa.tradepub.com/c/pubRD.mpl?sr=oc&_t=oc:&qf=w_dats04&ch=datacenterkids
|
||||
[3]: https://www.networkworld.com/article/3276025/20-hot-jobs-ambitious-it-pros-should-shoot-for.html
|
||||
[4]: https://www.networkworld.com/article/3046178/survey-finds-most-coders-are-self-taught.html
|
||||
[5]: https://pluralsight.pxf.io/c/321564/424552/7490?u=https%3A%2F%2Fwww.pluralsight.com%2Fpaths%2Fupgrading-your-technology-career
|
||||
[6]: https://www.networkworld.com/article/3289509/two-studies-show-the-data-center-is-thriving-instead-of-dying.html
|
||||
[7]: https://www.facebook.com/NetworkWorld/
|
||||
[8]: https://www.linkedin.com/company/network-world
|
||||
@ -1,3 +1,4 @@
|
||||
LuMing Translating
|
||||
Writing a Time Series Database from Scratch
|
||||
============================================================
|
||||
|
||||
|
||||
@ -1,4 +1,3 @@
|
||||
RHSNOW is translating.
|
||||
How To Create A Bootable Zorin OS USB Drive
|
||||
======
|
||||
![Zorin OS][17]
|
||||
|
||||
@ -1,3 +1,12 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How to use autofs to mount NFS shares)
|
||||
[#]: via: (https://opensource.com/article/18/6/using-autofs-mount-nfs-shares)
|
||||
[#]: author: (Alan Formy-Duval https://opensource.com/users/alanfdoss)
|
||||
|
||||
How to use autofs to mount NFS shares
|
||||
======
|
||||
|
||||
|
||||
@ -0,0 +1,65 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (lujun9972)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Get desktop notifications from Emacs shell commands ·)
|
||||
[#]: via: (https://blog.hoetzel.info/post/eshell-notifications/)
|
||||
[#]: author: (Jürgen Hötzel https://blog.hoetzel.info)
|
||||
|
||||
Get desktop notifications from Emacs shell commands ·
|
||||
======
|
||||
When interacting with the operating systems I always use [Eshell][1] because it integrates seamlessly with Emacs, supports (remote) [TRAMP][2] file names and also works nice on Windows.
|
||||
|
||||
After starting shell commands (like long running build jobs) I often lose track the task when switching buffers.
|
||||
|
||||
Thanks to Emacs [hooks][3] mechanism you can customize Emacs to call a elisp function when an external command finishes.
|
||||
|
||||
I use [John Wiegleys][4] excellent [alert][5] package to send desktop notifications:
|
||||
|
||||
```
|
||||
(require 'alert)
|
||||
|
||||
(defun eshell-command-alert (process status)
|
||||
"Send `alert' with severity based on STATUS when PROCESS finished."
|
||||
(let* ((cmd (process-command process))
|
||||
(buffer (process-buffer process))
|
||||
(msg (format "%s: %s" (mapconcat 'identity cmd " ") status)))
|
||||
(if (string-prefix-p "finished" status)
|
||||
(alert msg :buffer buffer :severity 'normal)
|
||||
(alert msg :buffer buffer :severity 'urgent))))
|
||||
|
||||
(add-hook 'eshell-kill-hook #'eshell-command-alert)
|
||||
```
|
||||
|
||||
[alert][5] rules can be setup programmatically. In my case I only want to get notified if the corresponding buffer is not visible:
|
||||
|
||||
```
|
||||
(alert-add-rule :status '(buried) ;only send alert when buffer not visible
|
||||
:mode 'eshell-mode
|
||||
:style 'notifications)
|
||||
```
|
||||
|
||||
This even works on [TRAMP][2] buffers. Below is a screenshot showing a Gnome desktop notification of a failed `make` command.
|
||||
|
||||
![../../img/eshell.png][6]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://blog.hoetzel.info/post/eshell-notifications/
|
||||
|
||||
作者：[Jürgen Hötzel][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://blog.hoetzel.info
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.gnu.org/software/emacs/manual/html_mono/eshell.html (Eshell)
|
||||
[2]: https://www.gnu.org/software/tramp/ (TRAMP)
|
||||
[3]: https://www.gnu.org/software/emacs/manual/html_node/emacs/Hooks.html (hooks)
|
||||
[4]: https://github.com/jwiegley (John Wiegleys)
|
||||
[5]: https://github.com/jwiegley/alert (alert)
|
||||
[6]: https://blog.hoetzel.info/img/eshell.png (../../img/eshell.png)
|
||||
@ -1,5 +1,5 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (suphgcm)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
|
||||
@ -1,104 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (DevOps for Network Engineers: Linux Foundation’s New Training Course)
|
||||
[#]: via: (https://itsfoss.com/devops-for-network-engineers/)
|
||||
[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/)
|
||||
|
||||
DevOps for Network Engineers: Linux Foundation’s New Training Course
|
||||
======
|
||||
|
||||
_**Linux Foundation has launched a[DevOps course for sysadmins][1] and network engineers. They are also offering a limited time 40% discount on the launch.**_
|
||||
|
||||
DevOps is no longer a buzzword. It has become the necessity for any IT company.
|
||||
|
||||
The role and responsibility of a sysadmin and a network engineer have changed as well. They are required to have knowledge of the DevOps tools popular in the IT industry.
|
||||
|
||||
If you are a sysadmin or a network engineer, you can no longer laugh off DevOps anymore. It’s time to learn new skills to stay relevant in today’s rapidly changing IT industry otherwise the ‘automation’ trend might cost you your job.
|
||||
|
||||
And who knows it better than Linux Foundation, the official organization behind Linux project and the employer of Linux-creator Linus Torvalds?
|
||||
|
||||
[Linux Foundation has a number of courses on Linux and related technologies][2] that help you in getting a job or improving your existing skills at work.
|
||||
|
||||
The [latest course offering][1] from Linux Foundation specifically focuses on sysadmins who would like to familiarize with DevOps tools.
|
||||
|
||||
### DevOps for Network Engineers Course
|
||||
|
||||
![][3]
|
||||
|
||||
[This course][1] is intended for existing sysadmins and network engineers. So you need to have some knowledge of Linux system administration, shell scripting and Python.
|
||||
|
||||
The course will help you with:
|
||||
|
||||
* Integrating into a DevOps/Agile environment
|
||||
* Familiarizing with commonly used DevOps tools
|
||||
* Collaborating on projects as DevOps
|
||||
* Confidently working with software and configuration files in version control
|
||||
* Recognizing the roles of SCRUM team members
|
||||
* Confidently applying Agile principles in an organization
|
||||
|
||||
|
||||
|
||||
This is the course outline:
|
||||
|
||||
* Chapter 1. Course Introduction
|
||||
* Chapter 2. Modern Project Management
|
||||
* Chapter 3. The DevOps Process: A Network Engineer’s Perspective
|
||||
* Chapter 4. Network Simulation and Testing with [Mininet][4]
|
||||
* Chapter 5. [OpenFlow][5] and [ONOS][6]
|
||||
* Chapter 6. Infrastructure as Code ([Ansible][7] Basics)
|
||||
* Chapter 7. Version Control ([Git][8])
|
||||
* Chapter 8. Continuous Integration and Continuous Delivery ([Jenkins][9])
|
||||
* Chapter 9. Using [Gerrit][10] in DevOps
|
||||
* Chapter 10. Jenkins, Gerrit and Code Review for DevOps
|
||||
* Chapter 11. The DevOps Process and Tools (Review)
|
||||
|
||||
|
||||
|
||||
Altogether, you get 25-30 hours of course material. The online course is self-paced and you can access the material for one year from the date of purchase.
|
||||
|
||||
_**Unlike most other courses on Linux Foundation, this is NOT a video course.**_
|
||||
|
||||
There is no certification for this course because it is more focused on learning and improving skills.
|
||||
|
||||
#### Get the course at a 40% discount (limited time)
|
||||
|
||||
The course costs $299 but since it’s just launched, they are offering 40% discount till March 1st, 2019. You can get the discount by using the **DEVOPSNET** coupon code at checkout.
|
||||
|
||||
[DevOps for Network Engineers][1]
|
||||
|
||||
By the way, if you are interested in Open Source development, you can benefit from the “[Introduction to Open Source Development, Git, and Linux][11]” video course. You can get a limited time 50% discount using **OSDEV50** code at the checkout.
|
||||
|
||||
Staying relevant is absolutely necessary in any industry, not just IT industry. Learning new skills that are in-demand in your industry is perhaps the best way in this regard.
|
||||
|
||||
What do you think? What are your views on the current automation trend? How would you go about it?
|
||||
|
||||
_Disclaimer: This post contains affiliate links. Please read our_ [_affiliate policy_][12] _for more details._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/devops-for-network-engineers/
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/abhishek/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: http://shrsl.com/1glcb
|
||||
[2]: https://shareasale.com/r.cfm?b=1074561&u=747593&m=59485&urllink=&afftrack=
|
||||
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/02/DevOps-for-Network-Engineers-800x450.png?resize=800%2C450&ssl=1
|
||||
[4]: http://mininet.org/
|
||||
[5]: https://en.wikipedia.org/wiki/OpenFlow
|
||||
[6]: https://onosproject.org/
|
||||
[7]: https://www.ansible.com/
|
||||
[8]: https://itsfoss.com/basic-git-commands-cheat-sheet/
|
||||
[9]: https://jenkins.io/
|
||||
[10]: https://www.gerritcodereview.com/
|
||||
[11]: https://shareasale.com/r.cfm?b=1193750&u=747593&m=59485&urllink=&afftrack=
|
||||
[12]: https://itsfoss.com/affiliate-policy/
|
||||
@ -1,171 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (What is 5G? How is it better than 4G?)
|
||||
[#]: via: (https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html#tk.rss_all)
|
||||
[#]: author: (Josh Fruhlinger https://www.networkworld.com/author/Josh-Fruhlinger/)
|
||||
|
||||
What is 5G? How is it better than 4G?
|
||||
======
|
||||
|
||||
### 5G networks will boost wireless throughput by a factor of 10 and may replace wired broadband. But when will they be available, and why are 5G and IoT so linked together?
|
||||
|
||||
![Thinkstock][1]
|
||||
|
||||
[5G wireless][2] is an umbrella term to describe a set of standards and technologies for a radically faster wireless internet that ideally is up to 20 times faster with 120 times less latency than 4G, setting the stage for IoT networking advances and support for new high-bandwidth applications.
|
||||
|
||||
## What is 5G? Technology or buzzword?
|
||||
|
||||
It will be years before the technology reaches its full potential worldwide, but meanwhile some 5G network services are being rolled out today. 5G is as much a marketing buzzword as a technical term, and not all services marketed as 5G are standard.
|
||||
|
||||
**[From Mobile World Congress:[The time of 5G is almost here][3].]**
|
||||
|
||||
## 5G speed vs 4G
|
||||
|
||||
With every new generation of wireless technology, the biggest appeal is increased speed. 5G networks have potential peak download speeds of [20 Gbps, with 10 Gbps being seen as typical][4]. That's not just faster than current 4G networks, which currently top out at around 1 Gbps, but also faster than cable internet connections that deliver broadband to many people's homes. 5G offers network speeds that rival optical-fiber connections.
|
||||
|
||||
Throughput alone isn't 5G's only important speed improvement; it also features a huge reduction in network latency*.* That's an important distinction: throughput measures how long it would take to download a large file, while latency is determined by network bottlenecks and delays that slow down responses in back-and-forth communication.
|
||||
|
||||
Latency can be difficult to quantify because it varies based on myriad network conditions, but 5G networks are capable of latency rates that are less than a millisecond in ideal conditions. Overall, 5G latency will be lower than 4G's by a factor of 60 to 120. That will make possible a number of applications such as virtual reality that delay makes impractical today.
|
||||
|
||||
## 5G technology
|
||||
|
||||
The technology underpinnings of 5G are defined by a series of standards that have been in the works for the better part of a decade. One of the most important of these is 5G New Radio, or 5G NR*,* formalized by the 3rd Generation Partnership Project, a standards organization that develops protocols for mobile telephony. 5G NR will dictate many of the ways in which consumer 5G devices will operate, and was [finalized in June of 2018][5].
|
||||
|
||||
**[[Take this mobile device management course from PluralSight and learn how to secure devices in your company without degrading the user experience.][6] ]**
|
||||
|
||||
A number of individual technologies have come together to make the speed and latency improvements of 5G possible, and below are some of the most important.
|
||||
|
||||
## Millimeter waves
|
||||
|
||||
5G networks will for the most part use frequencies in the 30 to 300 GHz range. (Wavelengths at these frequencies are between 1 and 10 millimeters, thus the name.) This high-frequency band can [carry much more information per unit of time than the lower-frequency signals][7] currently used by 4G LTE, which is generally below 1 GHz, or Wi-Fi, which tops out at 6 GHz.
|
||||
|
||||
Millimeter-wave technology has traditionally been expensive and difficult to deploy. Technical advances have overcome those difficulties, which is part of what's made 5G possible today.
|
||||
|
||||
## Small cells
|
||||
|
||||
One drawback of millimeter wave transmission is that it's more prone to interference than Wi-Fi or 4G signals as they pass through physical objects.
|
||||
|
||||
To overcome this, the model for 5G infrastructure will be different from 4G's. Instead of the large cellular-antenna masts we've come to accept as part of the landscape, 5G networks will be powered by [much smaller base stations spread throughout cities about 250 meters apart][8], creating cells of service that are also smaller.
|
||||
|
||||
These 5G base stations have lower power requirements than those for 4G and can be attached to buildings and utility poles more easily.
|
||||
|
||||
## Massive MIMO
|
||||
|
||||
Despite 5G base stations being much smaller than their 4G counterparts, they pack in many more antennas. These antennas are [multiple-input multiple-output (MIMO)][9], meaning that they can handle multiple two-way conversations over the same data signal simultaneously. 5G networks can handle more than [20 times more conversations in this way than 4G networks][10].
|
||||
|
||||
Massive MIMO promises to [radically improve on base station capacity limits][11], allowing individual base stations to have conversations with many more devices. This in particular is why 5G may drive wider adoption of IoT. In theory, a lot more internet-connected wireless gadgets will be able to be deployed in the same space without overwhelming the network.
|
||||
|
||||
## Beamforming
|
||||
|
||||
Making sure all these conversations go back and forth to the right places is tricky, especially with the aforementioned problems millimeter-wave signals have with interference. To overcome those issues, 5G stations deploy advanced beamforming techniques, which use constructive and destructive radio interference to make signals directional rather than broadcast. That effectively boosts signal strength and range in a particular direction.
|
||||
|
||||
## 5G availability
|
||||
|
||||
The first commercial 5G network was [rolled out in Qatar in May 2018][12]. Since then, networks have been popping up across the world, from Argentina to Vietnam. [Lifewire has a good, frequently updated list][13].
|
||||
|
||||
One thing to keep in mind, though, is that not all 5G networks deliver on all the technology's promises yet. Some early 5G offerings piggyback on existing 4G infrastructure, which reduces the potential speed gains; other services dubbed 5G for marketing purposes don't even comply with the standard. A closer look at offerings from U.S. wireless carriers will demonstrate some of the pitfalls.
|
||||
|
||||
## Wireless carriers and 5G
|
||||
|
||||
Technically, 5G is available in the U.S. today. But the caveats involved in that statement vary from carrier to carrier, demonstrating the long road that still lies ahead before 5G becomes omnipresent.
|
||||
|
||||
Verizon is making probably the biggest early 5G push. It announced [5G Home][14] in parts of four cities in October of 2018, a service that requires using a special 5G hotspot to connect to the network and feed it to your other devices via Wi-Fi.
|
||||
|
||||
Verizon planned an April rollout of a [mobile service in Minneapolis and Chicago][15], which will spread to other cities over the course of the year. Accessing the 5G network will cost customers an extra monthly fee plus what they’ll have to spend on a phone that can actually connect to it (more on that in a moment). As an added wrinkle, Verizon is deploying what it calls [5G TF][16], which doesn't match up with the 5G NR standard.
|
||||
|
||||
AT&T [announced the availability of 5G in 12 U.S. cities in December 2018][17], with nine more coming by the end of 2019, but even in those cities, availability is limited to the downtown areas. To use the network requires a special Netgear hotspot that connects to the service, then provides a Wi-Fi signal to phones and other devices.
|
||||
|
||||
Meanwhile, AT&T is also rolling out speed boosts to its 4G network, which it's dubbed 5GE even though these improvements aren't related to 5G networking. ([This is causing backlash][18].)
|
||||
|
||||
Sprint will have 5G service in parts of four cities by May of 2019, and five more by the end of the year. But while Sprint's 5G offering makes use of massive MIMO cells, they [aren't using millimeter-wave signals][19], meaning that Sprint users won't see as much of a speed boost as customers of other carriers.
|
||||
|
||||
T-Mobile is pursuing a similar model,and it [won't roll out its service until the end of 2019][20] because there won't be any phones to connect to it.
|
||||
|
||||
One kink that might stop a rapid spread of 5G is the need to spread out all those small-cell base stations. Their small size and low power requirements make them easier to deploy than current 4G tech in a technical sense, but that doesn't mean it's simple to convince governments and property owners to install dozens of them everywhere. Verizon actually set up a [website that you can use to petition your local elected officials][21] to speed up 5G base station deployment.
|
||||
|
||||
## **5G phones: When available? When to buy?**
|
||||
|
||||
The first major 5G phone to be announced is the Samsung Galaxy S10 5G, which should be available by the end of the summer of 2019. You can also order a "[Moto Mod][22]" from Verizon, which [transforms Moto Z3 phones into 5G-compatible device][23]s.
|
||||
|
||||
But unless you can't resist the lure of being an early adopter, you may wish to hold off for a bit; some of the quirks and looming questions about carrier rollout may mean that you end up with a phone that [isn't compatible with your carrier's entire 5G network][24].
|
||||
|
||||
One laggard that may surprise you is Apple: analysts believe that there won't be a [5G-compatible iPhone until 2020 at the earliest][25]. But this isn't out of character for the company; Apple [also lagged behind Samsung in releasing 4G-compatible phones][26] in back in 2012.
|
||||
|
||||
Still, the 5G flood is coming. 5G-compatible devices [dominated Barcelona's Mobile World Congress in 2019][3], so expect to have a lot more choice on the horizon.
|
||||
|
||||
## Why are people talking about 6G already?
|
||||
|
||||
Some experts say [5G won’t be able to meet the latency and reliability targets][27] it is shooting for. These skeptics are already looking ahead to 6G, which they say will try to address these projected shortcomings.
|
||||
|
||||
There is [a group that is researching new technologies that can be rolled into 6G][28] that calls itself
|
||||
|
||||
The Center for Converged TeraHertz Communications and Sensing (ComSenTer). Part of the spec they’re working on calls for 100Gbps speed for every device.
|
||||
|
||||
In addition to adding reliability, overcoming reliability and boosting speed, 6G is also trying to enable thousands of simultaneous connections. If successful, this feature could help to network IoT devices, which can be deployed in the thousands as sensors in a variety of industrial settings.
|
||||
|
||||
Even in its embryonic form, 6G may already be facing security concerns due to the emergence of newly discovered [potential for man-in-the-middle attacks in tera-hertz based networks][29]. The good news is that there’s plenty of time to find solutions to the problem. 6G networks aren’t expected to start rolling out until 2030.
|
||||
|
||||
**More about 5g networks:**
|
||||
|
||||
* [How enterprises can prep for 5G networks][30]
|
||||
* [5G vs 4G: How speed, latency and apps support differ][31]
|
||||
* [Private 5G networks are coming][32]
|
||||
* [5G and 6G wireless have security issues][33]
|
||||
* [How millimeter-wave wireless could help support 5G and IoT][34]
|
||||
|
||||
|
||||
|
||||
Join the Network World communities on [Facebook][35] and [LinkedIn][36] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html#tk.rss_all
|
||||
|
||||
作者：[Josh Fruhlinger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Josh-Fruhlinger/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://images.techhive.com/images/article/2017/04/5g-100718139-large.jpg
|
||||
[2]: https://www.networkworld.com/article/3203489/what-is-5g-wireless-networking-benefits-standards-availability-versus-lte.html
|
||||
[3]: https://www.networkworld.com/article/3354477/mobile-world-congress-the-time-of-5g-is-almost-here.html
|
||||
[4]: https://www.networkworld.com/article/3330603/5g-versus-4g-how-speed-latency-and-application-support-differ.html
|
||||
[5]: https://www.theverge.com/2018/6/15/17467734/5g-nr-standard-3gpp-standalone-finished
|
||||
[6]: https://pluralsight.pxf.io/c/321564/424552/7490?u=https%3A%2F%2Fwww.pluralsight.com%2Fcourses%2Fmobile-device-management-big-picture
|
||||
[7]: https://www.networkworld.com/article/3291323/millimeter-wave-wireless-could-help-support-5g-and-iot.html
|
||||
[8]: https://spectrum.ieee.org/video/telecom/wireless/5g-bytes-small-cells-explained
|
||||
[9]: https://www.networkworld.com/article/3250268/what-is-mu-mimo-and-why-you-need-it-in-your-wireless-routers.html
|
||||
[10]: https://spectrum.ieee.org/tech-talk/telecom/wireless/5g-researchers-achieve-new-spectrum-efficiency-record
|
||||
[11]: https://www.networkworld.com/article/3262991/future-wireless-networks-will-have-no-capacity-limits.html
|
||||
[12]: https://venturebeat.com/2018/05/14/worlds-first-commercial-5g-network-launches-in-qatar/
|
||||
[13]: https://www.lifewire.com/5g-availability-world-4156244
|
||||
[14]: https://www.digitaltrends.com/computing/verizon-5g-home-promises-up-to-gigabit-internet-speeds-for-50/
|
||||
[15]: https://lifehacker.com/heres-your-cheat-sheet-for-verizons-new-5g-data-plans-1833278817
|
||||
[16]: https://www.theverge.com/2018/10/2/17927712/verizon-5g-home-internet-real-speed-meaning
|
||||
[17]: https://www.cnn.com/2018/12/18/tech/5g-mobile-att/index.html
|
||||
[18]: https://www.networkworld.com/article/3339720/like-4g-before-it-5g-is-being-hyped.html?nsdr=true
|
||||
[19]: https://www.digitaltrends.com/mobile/sprint-5g-rollout/
|
||||
[20]: https://www.cnet.com/news/t-mobile-delays-full-600-mhz-5g-launch-until-second-half/
|
||||
[21]: https://lets5g.com/
|
||||
[22]: https://www.verizonwireless.com/support/5g-moto-mod-faqs/?AID=11365093&SID=100098X1555750Xbc2e857934b22ebca1a0570d5ba93b7c&vendorid=CJM&PUBID=7105813&cjevent=2e2150cb478c11e98183013b0a1c0e0c
|
||||
[23]: https://www.digitaltrends.com/cell-phone-reviews/moto-z3-review/
|
||||
[24]: https://www.businessinsider.com/samsung-galaxy-s10-5g-which-us-cities-have-5g-networks-2019-2
|
||||
[25]: https://www.cnet.com/news/why-apples-in-no-rush-to-sell-you-a-5g-iphone/
|
||||
[26]: https://mashable.com/2012/09/09/iphone-5-4g-lte/#hYyQUelYo8qq
|
||||
[27]: https://www.networkworld.com/article/3305359/6g-will-achieve-terabits-per-second-speeds.html
|
||||
[28]: https://www.networkworld.com/article/3285112/get-ready-for-upcoming-6g-wireless-too.html
|
||||
[29]: https://www.networkworld.com/article/3315626/5g-and-6g-wireless-technologies-have-security-issues.html
|
||||
[30]: https://%20https//www.networkworld.com/article/3306720/mobile-wireless/how-enterprises-can-prep-for-5g.html
|
||||
[31]: https://%20https//www.networkworld.com/article/3330603/mobile-wireless/5g-versus-4g-how-speed-latency-and-application-support-differ.html
|
||||
[32]: https://%20https//www.networkworld.com/article/3319176/mobile-wireless/private-5g-networks-are-coming.html
|
||||
[33]: https://www.networkworld.com/article/3315626/network-security/5g-and-6g-wireless-technologies-have-security-issues.html
|
||||
[34]: https://www.networkworld.com/article/3291323/mobile-wireless/millimeter-wave-wireless-could-help-support-5g-and-iot.html
|
||||
[35]: https://www.facebook.com/NetworkWorld/
|
||||
[36]: https://www.linkedin.com/company/network-world
|
||||
@ -1,91 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (MjSeven)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Command line quick tips: Cutting content out of files)
|
||||
[#]: via: (https://fedoramagazine.org/command-line-quick-tips-cutting-content-out-of-files/)
|
||||
[#]: author: (Stephen Snow https://fedoramagazine.org/author/jakfrost/)
|
||||
|
||||
Command line quick tips: Cutting content out of files
|
||||
======
|
||||
|
||||
![][1]
|
||||
|
||||
The Fedora distribution is a full featured operating system with an excellent graphical desktop environment. A user can point and click their way through just about any typical task easily. All of this wonderful ease of use masks the details of a powerful command line under the hood. This article is part of a series that shows you some common command line utilities. So let’s drop into the shell, and have a look at **cut**.
|
||||
|
||||
Often when you work in the command line, you are working with text files. Sometimes these files may be quite long. Reading them in their entirety, while feasible, can be time consuming and prone to errors. In this installment you’ll learn how to extract content from text files, and get the information you want from them.
|
||||
|
||||
It’s important to recognize that there are many ways to accomplish similar command line tasks in Fedora. The Fedora repositories include entire language systems for parsing and working with text, as an example. Also, there are multiple command line utilities available for just about any purpose conceivable in the shell. This article will only focus on using a few of those utility choices, to extract some information from a file and present it in a readable format.
|
||||
|
||||
### Making the cut
|
||||
|
||||
To illustrate this example use a standard sizable file on the system like _/etc/passwd_. As seen in a prior article in this series, you can execute the _cat_ command to view an entire file:
|
||||
|
||||
```
|
||||
$ cat /etc/passwd
|
||||
root:x:0:0:root:/root:/bin/bash
|
||||
bin:x:1:1:bin:/bin:/sbin/nologin
|
||||
daemon:x:2:2:daemon:/sbin:/sbin/nologin
|
||||
adm:x:3:4:adm:/var/adm:/sbin/nologin
|
||||
...
|
||||
```
|
||||
|
||||
This file contains information on all accounts present on the system. It has a specific format:
|
||||
|
||||
```
|
||||
name:password:user-id:group-id:comment:home-directory:shell
|
||||
```
|
||||
|
||||
Imagine that you want to simply have a list of all the account names on the system. If you could only cut out the _name_ value from each line. This is where the _cut_ command comes in handy! This command treats any input one line at a time, and extracts a specific part of the line.
|
||||
|
||||
The _cut_ command provides options for selecting parts of a line differently, and in this example two of them are needed, _-d_ which is an option to specify a delimiter type to use, and _-f_ which is an option to specify which field of the line to cut. The _-d_ option lets you declare the _delimiter_ that separates values in a line. In this case a colon (:) is used to separate values. The _-f_ option lets you choose which field value or values to extract. So for this example the command entered would be:
|
||||
|
||||
```
|
||||
$ cut -d: -f1 /etc/passwd
|
||||
root
|
||||
bin
|
||||
daemon
|
||||
adm
|
||||
...
|
||||
```
|
||||
|
||||
That’s great, it worked! But you get the printout to the standard output, which in a terminal session at least means the screen. What if you needed the information for another task to be done later? It would be really nice if there was a way to put the output of the _cut_ command into a text file to save it. There is an easy builtin shell function for such a task, the redirect function ( _>_ ).
|
||||
|
||||
```
|
||||
$ cut -d: -f1 /etc/passwd > names.txt
|
||||
```
|
||||
|
||||
This will place the output of cut into a file called _names.txt_ and you can check the contents with _cat:_
|
||||
|
||||
```
|
||||
$ cat names.txt
|
||||
root
|
||||
bin
|
||||
daemon
|
||||
adm
|
||||
...
|
||||
```
|
||||
|
||||
With two commands and one shell function, it was easy to identify using _cat_ , extract using _cut_ , and redirect the extracted information from one file, saving it to another file for later use.
|
||||
|
||||
* * *
|
||||
|
||||
_Photo by _[ _Joel Mbugua_][2]_ on _[_Unsplash_][3]_._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/command-line-quick-tips-cutting-content-out-of-files/
|
||||
|
||||
作者：[Stephen Snow][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://fedoramagazine.org/author/jakfrost/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://fedoramagazine.org/wp-content/uploads/2019/04/commandline-cutting-816x345.jpg
|
||||
[2]: https://unsplash.com/photos/tA5eSY_hay8?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
[3]: https://unsplash.com/search/photos/command-line?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
@ -1,262 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How To Install And Configure NTP Server And NTP Client In Linux?)
|
||||
[#]: via: (https://www.2daygeek.com/install-configure-ntp-server-ntp-client-in-linux/)
|
||||
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
|
||||
|
||||
How To Install And Configure NTP Server And NTP Client In Linux?
|
||||
======
|
||||
|
||||
You might heard this word many times and also you might had worked on this.
|
||||
|
||||
However, i will tell you clearly in this article about NTP Server setup and NTP Client setup
|
||||
|
||||
We will see about **[Chrony NTP Client setup][1]** later.
|
||||
|
||||
### What Is NTP Server?
|
||||
|
||||
NTP stands for Network Time Protocol.
|
||||
|
||||
It is a networking protocol that synchronize the clock between computer systems over the network.
|
||||
|
||||
In other hand I can say. It will keep the same time (It keep an accurate time) to all the systems which are connected to NTP server through NTP or Chrony client.
|
||||
|
||||
NTP can usually maintain time to within tens of milliseconds over the public Internet, and can achieve better than one millisecond accuracy in local area networks under ideal conditions.
|
||||
|
||||
It uses User Datagram Protocol (UDP) on port number 123 for send and receive timestamps. It’s a client/server application.
|
||||
|
||||
It send and receive timestamps using the User Datagram Protocol (UDP) on port number 123.
|
||||
|
||||
### What Is NTP Client?
|
||||
|
||||
NTP client will synchronize its clock to the network time server.
|
||||
|
||||
### What Is Chrony Client?
|
||||
|
||||
Chrony is replacement of NTP client. It can synchronize the system clock faster with better time accuracy and it can be particularly useful for the systems which are not online all the time.
|
||||
|
||||
### Why We Need NTP Server?
|
||||
|
||||
To keep all the servers in your organization in-sync with an accurate time to perform time based jobs.
|
||||
|
||||
To clarify this, I will tell you a scenario. Say for example, we have two servers (Server1 and Server2). The server1 usually complete the batch jobs at 10:55 then the server2 needs to run another job at 11:00 based on the server1 job completion report.
|
||||
|
||||
If both the system is using in a different time (if one system is ahead of the others, the others are behind that particular one) then we can’t perform this. To achieve this, we should setup NTP. Hope it cleared your doubts about NTP.
|
||||
|
||||
In this article, we are going to use the following setup to test this.
|
||||
|
||||
* **`NTP Server:`** HostName: CentOS7.2daygeek.com, IP:192.168.1.8, OS:CentOS 7
|
||||
* **`NTP Client:`** HostName: Ubuntu18.2daygeek.com, IP:192.168.1.5, OS:Ubuntu 18.04
|
||||
|
||||
|
||||
|
||||
### NTP SERVER SIDE: How To Install NTP Server In Linux?
|
||||
|
||||
There is no different packages for NTP server and NTP client since it’s a client/server model. The NTP package is available in distribution official repository so, use the distribution package manger to install it.
|
||||
|
||||
For **`Fedora`** system, use **[DNF Command][2]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo dnf install ntp
|
||||
```
|
||||
|
||||
For **`Debian/Ubuntu`** systems, use **[APT-GET Command][3]** or **[APT Command][4]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo apt install ntp
|
||||
```
|
||||
|
||||
For **`Arch Linux`** based systems, use **[Pacman Command][5]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo pacman -S ntp
|
||||
```
|
||||
|
||||
For **`RHEL/CentOS`** systems, use **[YUM Command][6]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo yum install ntp
|
||||
```
|
||||
|
||||
For **`openSUSE Leap`** system, use **[Zypper Command][7]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo zypper install ntp
|
||||
```
|
||||
|
||||
### How To Configure The NTP Server In Linux?
|
||||
|
||||
Once you have installed the NTP package, make sure you have to uncomment the following configuration in the `/etc/ntp.conf` file on server side.
|
||||
|
||||
By default the NTP server configuration relies on `X.distribution_name.pool.ntp.org`. If you want you can use the default configuration or you can change it as per your location (country specific) by visiting <https://www.ntppool.org/zone/@> site.
|
||||
|
||||
Say for example. If you are in India then your NTP server will be `0.in.pool.ntp.org` and it will work for most of the countries.
|
||||
|
||||
```
|
||||
# vi /etc/ntp.conf
|
||||
|
||||
restrict default kod nomodify notrap nopeer noquery
|
||||
restrict -6 default kod nomodify notrap nopeer noquery
|
||||
restrict 127.0.0.1
|
||||
restrict -6 ::1
|
||||
server 0.asia.pool.ntp.org
|
||||
server 1.asia.pool.ntp.org
|
||||
server 2.asia.pool.ntp.org
|
||||
server 3.asia.pool.ntp.org
|
||||
restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
|
||||
driftfile /var/lib/ntp/drift
|
||||
keys /etc/ntp/keys
|
||||
```
|
||||
|
||||
We have allowed only `192.168.1.0/24` subnet clients to access the NTP server.
|
||||
|
||||
Since firewall is enabled by default on RHEL 7 based distributions so, allow the ntp server/service.
|
||||
|
||||
```
|
||||
# firewall-cmd --add-service=ntp --permanent
|
||||
# firewall-cmd --reload
|
||||
```
|
||||
|
||||
Bounce the service once you update the configuration.
|
||||
|
||||
For sysvinit systems. For Debian based system we need to run `ntp` instead of ntpd.
|
||||
|
||||
```
|
||||
# service ntpd restart
|
||||
|
||||
# chkconfig ntpd on
|
||||
```
|
||||
|
||||
For systemctl systems. For Debian based system we need to run `ntp` instead of ntpd.
|
||||
|
||||
```
|
||||
# systemctl restart ntpd
|
||||
|
||||
# systemctl enable ntpd
|
||||
```
|
||||
|
||||
### NTP CLIENT SIDE: How To Install NTP Client On Linux?
|
||||
|
||||
As I mentioned earlier in this article. There is no specific package for NTP server and client. So, install the same package on client also.
|
||||
|
||||
For **`Fedora`** system, use **[DNF Command][2]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo dnf install ntp
|
||||
```
|
||||
|
||||
For **`Debian/Ubuntu`** systems, use **[APT-GET Command][3]** or **[APT Command][4]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo apt install ntp
|
||||
```
|
||||
|
||||
For **`Arch Linux`** based systems, use **[Pacman Command][5]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo pacman -S ntp
|
||||
```
|
||||
|
||||
For **`RHEL/CentOS`** systems, use **[YUM Command][6]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo yum install ntp
|
||||
```
|
||||
|
||||
For **`openSUSE Leap`** system, use **[Zypper Command][7]** to install ntp.
|
||||
|
||||
```
|
||||
$ sudo zypper install ntp
|
||||
```
|
||||
|
||||
I have installed and configured the NTP server on `CentOS7.2daygeek.com` so, append the same into all the client machines.
|
||||
|
||||
```
|
||||
# vi /etc/ntp.conf
|
||||
|
||||
restrict default kod nomodify notrap nopeer noquery
|
||||
restrict -6 default kod nomodify notrap nopeer noquery
|
||||
restrict 127.0.0.1
|
||||
restrict -6 ::1
|
||||
server CentOS7.2daygeek.com prefer iburst
|
||||
driftfile /var/lib/ntp/drift
|
||||
keys /etc/ntp/keys
|
||||
```
|
||||
|
||||
Bounce the service once you update the configuration.
|
||||
|
||||
For sysvinit systems. For Debian based system we need to run `ntp` instead of ntpd.
|
||||
|
||||
```
|
||||
# service ntpd restart
|
||||
|
||||
# chkconfig ntpd on
|
||||
```
|
||||
|
||||
For systemctl systems. For Debian based system we need to run `ntp` instead of ntpd.
|
||||
|
||||
```
|
||||
# systemctl restart ntpd
|
||||
|
||||
# systemctl enable ntpd
|
||||
```
|
||||
|
||||
Wait for few minutes post restart of the NTP service to get synchronize time from the NTP server.
|
||||
|
||||
Run the following commands to verify the NTP server synchronization status on Linux.
|
||||
|
||||
```
|
||||
# ntpq –p
|
||||
Or
|
||||
# ntpq -pn
|
||||
|
||||
remote refid st t when poll reach delay offset jitter
|
||||
==============================================================================
|
||||
*CentOS7.2daygee 133.243.238.163 2 u 14 64 37 0.686 0.151 16.432
|
||||
```
|
||||
|
||||
Run the following command to get the current status of ntpd.
|
||||
|
||||
```
|
||||
# ntpstat
|
||||
synchronised to NTP server (192.168.1.8) at stratum 3
|
||||
time correct to within 508 ms
|
||||
polling server every 64 s
|
||||
```
|
||||
|
||||
Finally run the `date` command.
|
||||
|
||||
```
|
||||
# date
|
||||
Tue Mar 26 23:17:05 CDT 2019
|
||||
```
|
||||
|
||||
If you are observing a significant offset in the NTP output. Run the following command to sync clock manually from the NTP server. Make sure that your NTP client should be inactive state when you perform the command.
|
||||
|
||||
```
|
||||
# ntpdate –uv CentOS7.2daygeek.com
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.2daygeek.com/install-configure-ntp-server-ntp-client-in-linux/
|
||||
|
||||
作者：[Magesh Maruthamuthu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.2daygeek.com/author/magesh/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.2daygeek.com/configure-ntp-client-using-chrony-in-linux/
|
||||
[2]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/
|
||||
[3]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[4]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[5]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/
|
||||
[6]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/
|
||||
[7]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/
|
||||
@ -1,135 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Installing Ubuntu MATE on a Raspberry Pi)
|
||||
[#]: via: (https://itsfoss.com/ubuntu-mate-raspberry-pi/)
|
||||
[#]: author: (Chinmay https://itsfoss.com/author/chinmay/)
|
||||
|
||||
Installing Ubuntu MATE on a Raspberry Pi
|
||||
======
|
||||
|
||||
_**Brief: This quick tutorial shows you how to install Ubuntu MATE on Raspberry Pi devices.**_
|
||||
|
||||
[Raspberry Pi][1] is by far the most popular SBC (Single Board Computer) and the go-to board for makers. [Raspbian][2] which is based on Debian is the official operating system for the Pi. It is lightweight, comes bundled with educational tools and gets the job done for most scenarios.
|
||||
|
||||
[Installing Raspbian][3] is easy as well but the problem with [Debian][4] is its slow upgrade cycles and older packages.
|
||||
|
||||
Running Ubuntu on the Raspberry Pi gives you a richer experience and up to date software. We have a few options when it comes to running Ubuntu on your Pi.
|
||||
|
||||
1. [Ubuntu MATE][5] : Ubuntu MATE is the only distribution which natively supports the Raspberry Pi with a complete desktop environment.
|
||||
2. [Ubuntu Server 18.04][6] \+ Installing a desktop environment manually.
|
||||
3. Using Images built by the [Ubuntu Pi Flavor Maker][7] community, _these images only support the Raspberry Pi 2B and 3B variants_ and are **not** updated to the latest LTS release.
|
||||
|
||||
|
||||
|
||||
The first option is the easiest and the quickest to set up while the second option gives you the freedom to install the desktop environment of your choice. I recommend going with either of the first two options.
|
||||
|
||||
Here are the links to download the Disc Images. In this article I’ll be covering Ubuntu MATE installation only.
|
||||
|
||||
### Installing Ubuntu MATE on Raspberry Pi
|
||||
|
||||
Go to the download page of Ubuntu MATE and get the recommended images.
|
||||
|
||||
![][8]
|
||||
|
||||
The experimental ARM64 version should only be used if you need to run 64-bit only applications like MongoDB on a Raspberry Pi server.
|
||||
|
||||
[Download Ubuntu MATE for Raspberry Pi][9]
|
||||
|
||||
#### Step 1: Setting Up the SD Card
|
||||
|
||||
The image file needs to be decompressed once downloaded. You can simply right click on it to extract it.
|
||||
|
||||
Alternatively, the following command will do the job.
|
||||
|
||||
```
|
||||
xz -d ubuntu-mate***.img.xz
|
||||
```
|
||||
|
||||
Alternatively you can use [7-zip][10] if you are on Windows.
|
||||
|
||||
Install **[Balena Etcher][11]** , we’ll use this tool to write the image to the SD card. Make sure that your SD card is at least 8 GB capacity.
|
||||
|
||||
Launch Etcher and select the image file and your SD card.
|
||||
|
||||
![][12]
|
||||
|
||||
Once the flashing process is complete the SD card is ready.
|
||||
|
||||
#### Step 2: Setting Up the Raspberry Pi
|
||||
|
||||
You probably already know that you need a few things to get started with Raspberry Pi such as a mouse, keyboard, HDMI cable etc. You can also [install Raspberry Pi headlessly without keyboard and mouse][13] but this tutorial is not about that.
|
||||
|
||||
* Plug in a mouse and a keyboard.
|
||||
* Connect the HDMI cable.
|
||||
* Insert the SD card into the SD card slot.
|
||||
|
||||
|
||||
|
||||
Power it on by plugging in the power cable. Make sure you have a good power supply (5V, 3A minimum). A bad power supply can reduce the performance.
|
||||
|
||||
#### Ubuntu MATE installation
|
||||
|
||||
Once you power on the Raspberry Pi, you’ll be greeted with a very familiar Ubuntu installation process. The process is pretty much straight forward from here.
|
||||
|
||||
![Select your keyboard layout][14]
|
||||
|
||||
![Select Your Timezone][15]
|
||||
|
||||
Select your WiFi network and enter the password in the network connection screen.
|
||||
|
||||
![Add Username and Password][16]
|
||||
|
||||
After setting the keyboard layout, timezone and user credentials you’ll be taken to the login screen after a few minutes. And voila! you are almost done.
|
||||
|
||||
![][17]
|
||||
|
||||
Once logged in, the first thing you should do is to [update Ubuntu][18]. You can use the command line for that.
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
sudo apt upgrade
|
||||
```
|
||||
|
||||
You can also use the Software Updater.
|
||||
|
||||
![][19]
|
||||
|
||||
Once the updates are finished installing you are good to go. You can also go ahead and install Raspberry Pi specific packages for GPIO and other I/O depending on your needs.
|
||||
|
||||
What made you think about installing Ubuntu on the Raspberry and how has your experience been with Raspbian? Let me know in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/ubuntu-mate-raspberry-pi/
|
||||
|
||||
作者：[Chinmay][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/chinmay/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.raspberrypi.org/
|
||||
[2]: https://www.raspberrypi.org/downloads/
|
||||
[3]: https://itsfoss.com/tutorial-how-to-install-raspberry-pi-os-raspbian-wheezy/
|
||||
[4]: https://www.debian.org/
|
||||
[5]: https://ubuntu-mate.org/
|
||||
[6]: https://wiki.ubuntu.com/ARM/RaspberryPi#Recovering_a_system_using_the_generic_kernel
|
||||
[7]: https://ubuntu-pi-flavour-maker.org/download/
|
||||
[8]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/ubuntu-mate-raspberry-pi-download.jpg?ssl=1
|
||||
[9]: https://ubuntu-mate.org/download/
|
||||
[10]: https://www.7-zip.org/download.html
|
||||
[11]: https://www.balena.io/etcher/
|
||||
[12]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/Screenshot-from-2019-04-08-01-36-16.png?ssl=1
|
||||
[13]: https://linuxhandbook.com/raspberry-pi-headless-setup/
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Keyboard-layout-ubuntu.jpg?fit=800%2C467&ssl=1
|
||||
[15]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/select-time-zone-ubuntu.jpg?fit=800%2C468&ssl=1
|
||||
[16]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Credentials-ubuntu.jpg?fit=800%2C469&ssl=1
|
||||
[17]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Desktop-ubuntu.jpg?fit=800%2C600&ssl=1
|
||||
[18]: https://itsfoss.com/update-ubuntu/
|
||||
[19]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/update-software.png?ssl=1
|
||||
@ -1,354 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (12 Single Board Computers: Alternative to Raspberry Pi)
|
||||
[#]: via: (https://itsfoss.com/raspberry-pi-alternatives/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
12 Single Board Computers: Alternative to Raspberry Pi
|
||||
======
|
||||
|
||||
_**Brief: Looking for a Raspberry Pi alternative? Here are some other single board computers to satisfy your DIY cravings.**_
|
||||
|
||||
Raspberry Pi is the most popular single board computer right now. You can use it for your DIY projects or can use it as a cost effective system to learn coding or maybe utilize a [media server software][1] on it to stream media at your convenience.
|
||||
|
||||
You can do a lot of things with Raspberry Pi but it is not the ultimate solution for all kinds of tinkerers. Some might be looking for a cheaper board and some might be on the lookout for a powerful one.
|
||||
|
||||
Whatever be the case, we do need Raspberry Pi alternatives for a variety of reasons. So, in this article, we will talk about the best ten single board computers that we think are the best Raspberry Pi alternatives.
|
||||
|
||||
![][2]
|
||||
|
||||
### Raspberry Pi alternatives to satisfy your DIY craving
|
||||
|
||||
The list is in no particular order of ranking. Some of the links here are affiliate links. Please read our [affiliate policy][3].
|
||||
|
||||
#### 1\. Onion Omega2+
|
||||
|
||||
![][4]
|
||||
|
||||
For just **$13** , the Omega2+ is one of the cheapest IoT single board computers you can find out there. It runs on LEDE (Linux Embedded Development Environment) Linux OS – a distribution based on [OpenWRT][5].
|
||||
|
||||
Its form factor, cost, and the flexibility that comes from running a customized version of Linux OS makes it a perfect fit for almost any type of IoT applications.
|
||||
|
||||
You can find [Onion Omega kit on Amazon][6] or order from their own website that would cost you extra shipping charges.
|
||||
|
||||
**Key Specifications**
|
||||
|
||||
* MT7688 SoC
|
||||
* 2.4 GHz IEEE 802.11 b/g/n WiFi
|
||||
* 128 MB DDR2 RAM
|
||||
* 32 MB on-board flash storage
|
||||
* MicroSD Slot
|
||||
* USB 2.0
|
||||
* 12 GPIO Pins
|
||||
|
||||
|
||||
|
||||
[Visit WEBSITE
|
||||
][7]
|
||||
|
||||
#### 2\. NVIDIA Jetson Nano Developer Kit
|
||||
|
||||
![][8]
|
||||
|
||||
This is a very unique and interesting Raspberry Pi alternative from NVIDIA for just **$99**. Yes, it’s not something that everyone can make use of – but for a specific group of tinkerers or developers.
|
||||
|
||||
NVIDIA explains it for the following use-case:
|
||||
|
||||
> NVIDIA® Jetson Nano™ Developer Kit is a small, powerful computer that lets you run multiple neural networks in parallel for applications like image classification, object detection, segmentation, and speech processing. All in an easy-to-use platform that runs in as little as 5 watts.
|
||||
>
|
||||
> nvidia
|
||||
|
||||
So, basically, if you are into AI and deep learning, you can make use of the developer kit. If you are curious, the production compute module of this will be arriving in June 2019.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* CPU: Quad-core ARM A57 @ 1.43 GHz
|
||||
* GPU: 128-core Maxwell
|
||||
* RAM: 4 GB 64-bit LPDDR4 25.6 GB/s
|
||||
* Display: HDMI 2.0
|
||||
* 4 x USB 3.0 and eDP 1.4
|
||||
|
||||
|
||||
|
||||
[VISIT WEBSITE
|
||||
][9]
|
||||
|
||||
#### 3\. ASUS Tinker Board S
|
||||
|
||||
![][10]
|
||||
|
||||
ASUS Tinker Board S isn’t the most affordable Raspberry Pi alternative at **$82** (on [Amazon][11]) but it is a powerful alternative. It features the same 40-pin connector that you’d normally find in the standard Raspberry Pi 3 Model but offers a powerful processor and a GPU.Also, the size of the Tinker Board S is exactly the same as a standard Raspberry Pi 3.
|
||||
|
||||
The main highlight of this board is the presence of 16 GB [eMMC][12] (in layman terms, it has got SSD-like storage on board that makes it faster while working on it).
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Rockchip Quad-Core RK3288 processor
|
||||
* 2 GB DDR3 RAM
|
||||
* Integrated Graphics Processor
|
||||
* ARM® Mali™-T764 GPU
|
||||
* 16 GB eMMC
|
||||
* MicroSD Card Slot
|
||||
* 802.11 b/g/n, Bluetooth V4.0 + EDR
|
||||
* USB 2.0
|
||||
* 28 GPIO pins
|
||||
* HDMI Interface
|
||||
|
||||
|
||||
|
||||
[Visit website
|
||||
][13]
|
||||
|
||||
#### 4\. ClockworkPi
|
||||
|
||||
![][14]
|
||||
|
||||
Clockwork Pi is usually a part of the [GameShell Kit][15] if you are looking to assemble a modular retro gaming console. However, you can purchase the board separately for $49.
|
||||
|
||||
Its compact size, WiFi connectivity, and the presence of micro HDMI port make it a great choice for a lot of things.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Allwinner R16-J Quad-core Cortex-A7 CPU @1.2GHz
|
||||
* Mali-400 MP2 GPU
|
||||
* RAM: 1GB DDR3
|
||||
* WiFi & Bluetooth v4.0
|
||||
* Micro HDMI output
|
||||
* MicroSD Card Slot
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][16]
|
||||
|
||||
#### 5\. Arduino Mega 2560
|
||||
|
||||
![][17]
|
||||
|
||||
If you are into robotic projects or you want something for a 3D printer – Arduino Mega 2560 will be a handy replacement to Raspberry Pi. Unlike Raspberry Pi, it is based on a microcontroller and not a microprocessor.
|
||||
|
||||
It would cost you $38.50 on their [official site][18] and and around [$33 on Amazon][19].
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Microcontroller: ATmega2560
|
||||
* Clock Speed: 16 MHz
|
||||
* Digital I/O Pins: 54
|
||||
* Analog Input Pins: 16
|
||||
* Flash Memory: 256 KB of which 8 KB used by bootloader
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][18]
|
||||
|
||||
#### 6\. Rock64 Media Board
|
||||
|
||||
![][20]
|
||||
|
||||
For the same investment as you would on a Raspberry Pi 3 B+, you will be getting a faster processor and double the memory on Rock64 Media Board. In addition, it also offers a cheaper alternative to Raspberry Pi if you want the 1 GB RAM model – which would cost $10 less.
|
||||
|
||||
Unlike Raspberry Pi, you do not have wireless connectivity support here but the presence of USB 3.0 and HDMI 2.0 does make a good difference if that matters to you.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Rockchip RK3328 Quad-Core ARM Cortex A53 64-Bit Processor
|
||||
* Supports up to 4GB 1600MHz LPDDR3 RAM
|
||||
* eMMC module socket
|
||||
* MicroSD Card slot
|
||||
* USB 3.0
|
||||
* HDMI 2.0
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][21]
|
||||
|
||||
#### 7\. Odroid-XU4
|
||||
|
||||
![][22]
|
||||
|
||||
Odroid-XU4 is the perfect alternative to Raspberry Pi if you have room to spend a little more ($80-$100 or even lower, depending on the store/availability).
|
||||
|
||||
It is indeed a powerful replacement and technically a bit smaller in size. The support for eMMC and USB 3.0 makes it faster to work with.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Samsung Exynos 5422 Octa ARM Cortex™-A15 Quad 2Ghz and Cortex™-A7 Quad 1.3GHz CPUs
|
||||
* 2Gbyte LPDDR3 RAM
|
||||
* GPU: Mali-T628 MP6
|
||||
* USB 3.0
|
||||
* HDMI 1.4a
|
||||
* eMMC 5.0 module socket
|
||||
* MicroSD Card Slot
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][23]
|
||||
|
||||
#### 8\. **PocketBeagle**
|
||||
|
||||
![][24]
|
||||
|
||||
It is an incredibly small SBC – almost similar to the Raspberry Pi Zero. However, it would cost you the same as that of a full-sized Raspberry Pi 3 model. The main highlight here is that you can use it as a USB key-fob and then access the Linux terminal to work on it.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Processor: Octavo Systems OSD3358 1GHz ARM® Cortex-A8
|
||||
* RAM: 512 MB DDR3
|
||||
* 72 expansion pin headers
|
||||
* microUSB
|
||||
* USB 2.0
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][25]
|
||||
|
||||
#### 9\. Le Potato
|
||||
|
||||
![][26]
|
||||
|
||||
Le Potato by [Libre Computer][27], also identified by its model number AML-S905X-CC. It would [cost you $45][28].
|
||||
|
||||
If you want double the memory along with HDMI 2.0 interface by spending a bit more than a Raspberry Pi – this would be the perfect choice. Although, you won’t find wireless connectivity baked in.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Amlogic S905X SoC
|
||||
* 2GB DDR3 SDRAM
|
||||
* USB 2.0
|
||||
* HDMI 2.0
|
||||
* microUSB
|
||||
* MicroSD Card Slot
|
||||
* eMMC Interface
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][29]
|
||||
|
||||
#### 10\. Banana Pi M64
|
||||
|
||||
![][30]
|
||||
|
||||
It comes loaded with 8 Gigs of eMMC – which is the key highlight of this Raspberry Pi alternative. For the very same reason, it would cost you $60.
|
||||
|
||||
The presence of HDMI interface makes it 4K-ready. In addition, Banana Pi offers a lot more variety of open source SBCs as an alternative to Raspberry Pi.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* 1.2 Ghz Quad-Core ARM Cortex A53 64-Bit Processor-R18
|
||||
* 2GB DDR3 SDRAM
|
||||
* 8 GB eMMC
|
||||
* WiFi & Bluetooth
|
||||
* USB 2.0
|
||||
* HDMI
|
||||
|
||||
|
||||
|
||||
[visit website
|
||||
][31]
|
||||
|
||||
#### 11\. Orange Pi Zero
|
||||
|
||||
![][32]
|
||||
|
||||
The Orange Pi Zero is an incredibly cheap alternative to Raspberry Pi. You will be able to get it for almost $10 on Aliexpress or Amazon. For a [little more investment, you can get 512 MB RAM][33].
|
||||
|
||||
If that isn’t sufficient, you can also go for Orange Pi 3 with better specifications which will cost you around $25.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* H2 Quad-core Cortex-A7
|
||||
* Mali400MP2 GPU
|
||||
* RAM: Up to 512 MB
|
||||
* TF Card support
|
||||
* WiFi
|
||||
* USB 2.0
|
||||
|
||||
|
||||
|
||||
[Visit website
|
||||
][34]
|
||||
|
||||
#### 12\. VIM 2 SBC by Khadas
|
||||
|
||||
![][35]
|
||||
|
||||
VIM 2 by Khadas is one of the latest SBCs that you can grab with Bluetooth 5.0 on board. It [starts from $99 (the basic model) and goes up to $140][36].
|
||||
|
||||
The basic model includes 2 GB RAM, 16 GB eMMC and Bluetooth 4.1. However, the Pro/Max versions would include Bluetooth 5.0, more memory, and more eMMC storage.
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Amlogic S912 1.5GHz 64-bit Octa-Core CPU
|
||||
* T820MP3 GPU
|
||||
* Up to 3 GB DDR4 RAM
|
||||
* Up to 64 GB eMMC
|
||||
* Bluetooth 5.0 (Pro/Max)
|
||||
* Bluetooth 4.1 (Basic)
|
||||
* HDMI 2.0a
|
||||
* WiFi
|
||||
|
||||
|
||||
|
||||
**Wrapping Up**
|
||||
|
||||
We do know that there are different types of single board computers. Some are better than Raspberry Pi – and some scaled down versions of it for a cheaper price tag. Also, SBCs like Jetson Nano have been tailored for a specific use. So, depending on what you require – you should verify the specifications of the single board computer.
|
||||
|
||||
If you think that you know about something that is better than the ones mentioned above, feel free to let us know in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/raspberry-pi-alternatives/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://itsfoss.com/best-linux-media-server/
|
||||
[2]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/raspberry-pi-alternatives.png?resize=800%2C450&ssl=1
|
||||
[3]: https://itsfoss.com/affiliate-policy/
|
||||
[4]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/omega-2-plus-e1555306748755-800x444.jpg?resize=800%2C444&ssl=1
|
||||
[5]: https://openwrt.org/
|
||||
[6]: https://amzn.to/2Xj8pkn
|
||||
[7]: https://onion.io/store/omega2p/
|
||||
[8]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Jetson-Nano-e1555306350976-800x590.jpg?resize=800%2C590&ssl=1
|
||||
[9]: https://developer.nvidia.com/embedded/buy/jetson-nano-devkit
|
||||
[10]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/asus-tinker-board-s-e1555304945760-800x450.jpg?resize=800%2C450&ssl=1
|
||||
[11]: https://amzn.to/2XfkOFT
|
||||
[12]: https://en.wikipedia.org/wiki/MultiMediaCard
|
||||
[13]: https://www.asus.com/in/Single-Board-Computer/Tinker-Board-S/
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/clockwork-pi-e1555305016242-800x506.jpg?resize=800%2C506&ssl=1
|
||||
[15]: https://itsfoss.com/gameshell-console/
|
||||
[16]: https://www.clockworkpi.com/product-page/cpi-v3-1
|
||||
[17]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/arduino-mega-2560-e1555305257633.jpg?ssl=1
|
||||
[18]: https://store.arduino.cc/usa/mega-2560-r3
|
||||
[19]: https://amzn.to/2KCi041
|
||||
[20]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/ROCK64_board-e1555306092845-800x440.jpg?resize=800%2C440&ssl=1
|
||||
[21]: https://www.pine64.org/?product=rock64-media-board-computer
|
||||
[22]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/odroid-xu4.jpg?fit=800%2C354&ssl=1
|
||||
[23]: https://www.hardkernel.com/shop/odroid-xu4-special-price/
|
||||
[24]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/PocketBeagle.jpg?fit=800%2C450&ssl=1
|
||||
[25]: https://beagleboard.org/p/products/pocketbeagle
|
||||
[26]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/aml-libre.-e1555306237972-800x514.jpg?resize=800%2C514&ssl=1
|
||||
[27]: https://libre.computer/
|
||||
[28]: https://amzn.to/2DpG3xl
|
||||
[29]: https://libre.computer/products/boards/aml-s905x-cc/
|
||||
[30]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/banana-pi-m6.jpg?fit=800%2C389&ssl=1
|
||||
[31]: http://www.banana-pi.org/m64.html
|
||||
[32]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/orange-pi-zero.jpg?fit=800%2C693&ssl=1
|
||||
[33]: https://amzn.to/2IlI81g
|
||||
[34]: http://www.orangepi.org/orangepizero/index.html
|
||||
[35]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/khadas-vim-2-e1555306505640-800x563.jpg?resize=800%2C563&ssl=1
|
||||
[36]: https://amzn.to/2UDvrFE
|
||||
@ -1,105 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Ubuntu 19.04 ‘Disco Dingo’ Has Arrived: Downloads Available Now!)
|
||||
[#]: via: (https://itsfoss.com/ubuntu-19-04-release/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
Ubuntu 19.04 ‘Disco Dingo’ Has Arrived: Downloads Available Now!
|
||||
======
|
||||
|
||||
It’s the time to disco! Why? Well, Ubuntu 19.04 ‘Disco Dingo’ is here and finally available to download. Although, we are aware of the [new features in Ubuntu 19.04][1] – I will mention a few important things below and would also point you to the official links to download it and get started.
|
||||
|
||||
### Ubuntu 19.04: What You Need To Know
|
||||
|
||||
Here are a few things you should know about Ubuntu 19.04 Disco Dingo release.
|
||||
|
||||
#### Ubuntu 19.04 is not an LTS Release
|
||||
|
||||
Unlike Ubuntu 18.04 LTS, this will not be [supported for 10 years][2]. Instead, the non-LTS 19.04 will be supported for **9 months until January 2020.**
|
||||
|
||||
So, if you have a production environment, we may not recommend upgrading it right away. For example, if you have a server that runs on Ubuntu 18.04 LTS – it may not be a good idea to upgrade it to 19.04 just because it is an exciting release.
|
||||
|
||||
However, for users who want the latest and greatest installed on their machines can try it out.
|
||||
|
||||
![][3]
|
||||
|
||||
#### Ubuntu 19.04 is a sweet update for NVIDIA GPU Owners
|
||||
|
||||
_Martin Wimpress_ (from Canonical) mentioned that Ubuntu 19.04 is particularly a big deal for NVIDIA GPU owners in the final release notes of Ubuntu MATE 19.04 (one of the Ubuntu flavors) on [GitHub][4].
|
||||
|
||||
In other words, while installing the proprietary graphics driver – it now selects the best driver compatible with your particular GPU model.
|
||||
|
||||
#### Ubuntu 19.04 Features
|
||||
|
||||
Even though we have already discussed the [best features of Ubuntu 19.04][1] Disco Dingo, it is worth mentioning that I’m exciting about the desktop updates (GNOME 3.32) and the Linux Kernel (5.0) that comes as one of the major changes in this release.
|
||||
|
||||
#### Upgrading from Ubuntu 18.10 to 19.04
|
||||
|
||||
If you have Ubuntu 18.10 installed, you should upgrade it for obvious reasons. 18.10 will reach its end of life in July 2019 – so we recommend you to upgrade it to 19.04.
|
||||
|
||||
To do that, you can simply head on to the “ **Software and Updates** ” settings and then navigate your way to the “ **Updates** ” tab.
|
||||
|
||||
Now, change the option for – **Notify me of a new Ubuntu version** to “ _For any new version_ “.
|
||||
|
||||
When you run the update manager now, you should see that Ubuntu 19.04 is available now.
|
||||
|
||||
![][5]
|
||||
|
||||
#### Upgrading from Ubuntu 18.04 to 19.04
|
||||
|
||||
It is not recommended to directly upgrade from 18.04 to 19.04 because you will have to update the OS to 18.10 first and then proceed to get 19.04 on board.
|
||||
|
||||
Instead, you can simply download the official ISO image of Ubuntu 19.04 and then re-install Ubuntu on your system.
|
||||
|
||||
### Ubuntu 19.04: Downloads Available for all flavors
|
||||
|
||||
As per the [release notes][6], Ubuntu 19.04 is available to download now. You can get the torrent or the ISO file on its official release download page.
|
||||
|
||||
[Download Ubuntu 19.04][7]
|
||||
|
||||
If you need a different desktop environment or need something specific, you should check out the official flavors of Ubuntu available:
|
||||
|
||||
* [Ubuntu MATE][8]
|
||||
* [Kubuntu][9]
|
||||
* [Lubuntu][10]
|
||||
* [Ubuntu Budgie][11]
|
||||
* [Ubuntu Studio][12]
|
||||
* [Xubuntu][13]
|
||||
|
||||
|
||||
|
||||
Some of the above mentioned Ubuntu flavors haven’t put the 19.04 release on their download yet. But you can [still find the ISOs on the Ubuntu’s release note webpage][6]. Personally, I use Ubuntu with GNOME desktop. You can choose whatever you like.
|
||||
|
||||
**Wrapping Up**
|
||||
|
||||
What do you think about Ubuntu 19.04 Disco Dingo? Are the new features exciting enough? Have you tried it yet? Let us know in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/ubuntu-19-04-release/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://itsfoss.com/ubuntu-19-04-release-features/
|
||||
[2]: https://itsfoss.com/ubuntu-18-04-ten-year-support/
|
||||
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2018/11/ubuntu-19-04-Disco-Dingo-default-wallpaper.jpg?resize=800%2C450&ssl=1
|
||||
[4]: https://github.com/ubuntu-mate/ubuntu-mate.org/blob/master/blog/20190418-ubuntu-mate-disco-final-release.md
|
||||
[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/ubuntu-19-04-upgrade-available.jpg?ssl=1
|
||||
[6]: https://wiki.ubuntu.com/DiscoDingo/ReleaseNotes
|
||||
[7]: https://www.ubuntu.com/download/desktop
|
||||
[8]: https://ubuntu-mate.org/download/
|
||||
[9]: https://kubuntu.org/getkubuntu/
|
||||
[10]: https://lubuntu.me/cosmic-released/
|
||||
[11]: https://ubuntubudgie.org/downloads
|
||||
[12]: https://ubuntustudio.org/2019/04/ubuntu-studio-19-04-released/
|
||||
[13]: https://xubuntu.org/download/
|
||||
@ -1,78 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (This is how System76 does open hardware)
|
||||
[#]: via: (https://opensource.com/article/19/4/system76-hardware)
|
||||
[#]: author: (Don Watkins https://opensource.com/users/don-watkins)
|
||||
|
||||
This is how System76 does open hardware
|
||||
======
|
||||
What sets the new Thelio line of desktops apart from the rest.
|
||||
![metrics and data shown on a computer screen][1]
|
||||
|
||||
Most people know very little about the hardware in their computers. As a long-time Linux user, I've had my share of frustration while getting my wireless cards, video cards, displays, and other hardware working with my chosen distribution. Proprietary hardware often makes it difficult to determine why an Ethernet controller, wireless controller, or mouse performs differently than we expect. As Linux distributions have matured, this has become less of a problem, but we still see some quirks with touchpads and other peripherals, especially when we don't know much—if anything—about our underlying hardware.
|
||||
|
||||
Companies like [System76][2] aim to take these types of problems out of the Linux user experience. System76 manufactures a line of Linux laptops, desktops, and servers, and even offers its own Linux distro, [Pop! OS][3], as an option for buyers, Recently I had the privilege of visiting System76's plant in Denver for [the unveiling][4] of [Thelio][5], its new desktop product line.
|
||||
|
||||
### About Thelio
|
||||
|
||||
System76 says Thelio's open hardware daughterboard, named Thelio Io after the fifth moon of Jupiter, is one thing that makes the computer unique in the marketplace. Thelio Io is certified [OSHWA #us000145][6] and has four SATA ports for storage and an embedded controller for fan and power button control. Thelio Io SAS is certified [OSHWA #us000146][7] and has four U.2 ports for storage and no embedded controller. During a demonstration, System76 showed how these components adjust fans throughout the chassis to optimize the unit's performance.
|
||||
|
||||
The controller also runs the power button and the LED ring around the button, which glows at 100% brightness when it is pressed. This provides both tactile and visual confirmation that the unit is being powered on. While the computer is in use, the button is set to 35% brightness, and when it's in suspend mode, it pulses between 2.35% and 25%. When the computer is off, the LED remains dimly lit so that it's easy to find the power control in a dark room.
|
||||
|
||||
Thelio's embedded controller is a low-power [ATmega32U4][8] microchip, and the controller's setup can be prototyped with an Arduino Micro. The number of Thelio Io boards changes depending on which Thelio model you purchase.
|
||||
|
||||
Thelio is also perhaps the best-designed computer case and system I have ever seen. You'll probably agree if you have ever skinned your knuckles trying to operate inside a typical PC case. I have done this a number of times, and I have the scars to prove it.
|
||||
|
||||
### Why open hardware?
|
||||
|
||||
The boards were designed in [KiCAD][9], and you can access all of Thelio's design files under GPL on [GitHub][10]. So, why would a company that competes with other PC manufacturers design a unique interface then license it openly? It's because the company recognizes the value of open design and the ability to share and adjust an I/O board to your needs, even if you're a competitor in the marketplace.
|
||||
|
||||
![Don Watkins speaks with System76 CEO Carl Richell at the Thelio launch event.][11]
|
||||
|
||||
Don Watkins speaks with System76 CEO Carl Richell at the [Thelio launch event][12].
|
||||
|
||||
I asked [Carl Richell][13], System76's founder and CEO, whether the company is concerned that openly licensing its hardware designs means someone could take its unique design and use it to drive System76 out of business. He said:
|
||||
|
||||
> Open hardware benefits all of us. It's how we further advance technology and make it more available to everyone. We welcome anyone who wishes to improve on Thelio's design to do so. Opening the hardware not only helps advance improvements of our computers more quickly, but it also empowers our customers to truly own 100% of their device. Our goal is to remove as much proprietary functioning as we can, while still producing a competitive Linux computer for customers.
|
||||
>
|
||||
> We've been working with the Linux community for over 13 years to create a flawless and digestible experience on all of our laptops, desktops, and servers. Our long tenure serving the Linux community, providing our customers with a high level of service, and our personability are what makes System76 unique.
|
||||
|
||||
I also asked Carl why open hardware makes sense for System76 and the PC business in general. He replied:
|
||||
|
||||
> System76 was founded on the idea that technology should be open and accessible to everyone. We're not yet at the point where we can create a computer that is 100% open source, but with open hardware, we're one large, essential step closer to reaching that point.
|
||||
>
|
||||
> We live in an era where technology has become a utility. Computers are tools for people at every level of education and across many industries. With everyone's needs specific, each person has their own ideas on how they might improve the computer and its software as their primary tool. Having our computers open allows these ideas to come to fruition, which in turn makes the technology a more powerful tool. In an open environment, we constantly get to iterate a better PC. And that's kind of cool.
|
||||
|
||||
We wrapped up our conversation by talking about System76's roadmap, which includes open hardware mini PCs and, eventually, laptops. Existing mini PCs and laptops sold under the System76 brand are manufactured by other vendors and are not based on open hardware (although their Linux software is, of course, open source).
|
||||
|
||||
Designing and supporting open hardware is a game-changer in the PC business, and it is what sets System76's new Thelio line of desktop computers apart.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/system76-hardware
|
||||
|
||||
作者：[Don Watkins ][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/don-watkins
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/metrics_data_dashboard_system_computer_analytics.png?itok=oxAeIEI- (metrics and data shown on a computer screen)
|
||||
[2]: https://system76.com/
|
||||
[3]: https://opensource.com/article/18/1/behind-scenes-popos-linux
|
||||
[4]: /article/18/11/system76-thelio-desktop-computer
|
||||
[5]: https://system76.com/desktops
|
||||
[6]: https://certification.oshwa.org/us000145.html
|
||||
[7]: https://certification.oshwa.org/us000146.html
|
||||
[8]: https://www.microchip.com/wwwproducts/ATmega32u4
|
||||
[9]: http://kicad-pcb.org/
|
||||
[10]: https://github.com/system76/thelio-io
|
||||
[11]: https://opensource.com/sites/default/files/uploads/don_system76_ceo.jpg (Don Watkins speaks with System76 CEO Carl Richell at the Thelio launch event.)
|
||||
[12]: https://trevgstudios.smugmug.com/System76/121418-Thelio-Press-Event/i-FKWFxFv
|
||||
[13]: https://www.linkedin.com/in/carl-richell-9435781
|
||||
@ -1,147 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (New Features Coming to Debian 10 Buster Release)
|
||||
[#]: via: (https://itsfoss.com/new-features-coming-to-debian-10-buster-release/)
|
||||
[#]: author: (Shirish https://itsfoss.com/author/shirish/)
|
||||
|
||||
New Features Coming to Debian 10 Buster Release
|
||||
======
|
||||
|
||||
Debian 10 Buster is nearing its release. The first release candidate is already out and we should see the final release, hopefully, in a few weeks.
|
||||
|
||||
If you are excited about this major new release, let me tell you what’s in it for you.
|
||||
|
||||
### Debian 10 Buster Release Schedule
|
||||
|
||||
There is no set release date for [Debian 10 Buster][1]. Why is that so? Unlike other distributions, [Debian][2] doesn’t do time-based releases. It instead focuses on fixing release-critical bugs. Release-critical bugs are bugs which have either security issues [CVE’s][3] or some other critical issues which prevent Debian from releasing.
|
||||
|
||||
Debian has three parts in its archive, called Main, contrib and non-free. Of the three, Debian Developers and Release Managers are most concerned that the packages which form the bedrock of the distribution i.e. Main is rock stable. So they make sure that there aren’t any major functional or security issues. They are also given priority values such as Essential, Required, Important, Standard, Optional and Extra. More on this in some later Debian article.
|
||||
|
||||
This is necessary because Debian is used as a server in many different environments and people have come to depend on Debian. They also look at upgrade cycles to see nothing breaks for which they look for people to test and see if something breaks while upgrading and inform Debian of the same.
|
||||
|
||||
This commitment to stability is one of the [many reasons why I love to use Debian][4].
|
||||
|
||||
### What’s new in Debian 10 Buster Release
|
||||
|
||||
Here are a few visual and under the hood changes in the upcoming major release of Debian.
|
||||
|
||||
#### New theme and wallpaper
|
||||
|
||||
The Debian theme for Buster is called [FuturePrototype][5] and can be seen below:
|
||||
|
||||
![Debian Buster FuturePrototype Theme][6]
|
||||
|
||||
#### 1\. GNOME Desktop 3.30
|
||||
|
||||
The GNOME desktop which was 1.3.22 in Debian Stretch is updated to 1.3.30 in Buster. Some of the new packages included in this GNOME desktop release are gnome-todo, tracker instead of tracker-gui , dependency against gstreamer1.0-packagekit so there is automatic codec installation for playing movies etc. The big move has been all packages being moved from libgtk2+ to libgtk3+ .
|
||||
|
||||
#### 2\. Linux Kernel 4.19.0-4
|
||||
|
||||
Debian uses LTS Kernel versions so you can expect much better hardware support and long 5 year maintainance and support cycle from Debian. From kernel 4.9.0.3 we have come to 4.19.0-4 .
|
||||
|
||||
```
|
||||
$ uname -r
|
||||
4.19.0-4-amd64
|
||||
```
|
||||
|
||||
#### 3\. OpenJDK 11.0
|
||||
|
||||
For a long time Debian was stuck on OpenJDK 8.0. Now in Debian Buster we have moved to OpenJDK 11.0 and have a team which will take care of new versions.
|
||||
|
||||
#### 4\. AppArmor Enabled by Default
|
||||
|
||||
In Debian Buster [AppArmor][7] will be enabled by default. While this is a good thing, care would have to be taken care by system administrators to enable correct policies. This is only the first step and would need fixing probably lot of scripts to be as useful as been envisioned for the user.
|
||||
|
||||
#### 5\. Nodejs 10.15.2
|
||||
|
||||
For a long time Debian had Nodejs 4.8 in the repo. In this cycle Debian has moved to Nodejs 10.15.2 . In fact, Debian Buster has many javascript libraries such as yarnpkg (an npm alternative) and many others.
|
||||
|
||||
Of course, you can [install latest Nodejs in Debian][8] from the project’s repository but it’s good to see newer version in Debian repository.
|
||||
|
||||
#### 6\. NFtables replaces iptables
|
||||
|
||||
Debian buster provides nftables as a full replacement to iptables which means better and easier syntax, better support for dual-stack ipv4-v6 firewalls and more.
|
||||
|
||||
#### 7\. Support for lot of ARM 64 and ARMHF SBC Boards.
|
||||
|
||||
There has been a constant stream of new SBC boards which Debian is supporting, the latest amongst these are pine64_plus, pinebook for ARM64, while Firefly-RK3288, u-boot-rockchip for ARMHF 64 as well as Odroid HC1/HC2 boards, SolidRun Cubox-i Dual/Quad (1.5som), and SolidRun Cubox-i Dual/Quad (1.5som+emmc) boards, Cubietruckplus as well. There is support for Rock 64, Banana Pi M2 Berry, Pine A64 LTS Board, Olimex A64 Teres-1 as well as Raspberry Pi 1, Zero and Pi 3. Support will be out-of-the box for RISC-V systems as well.
|
||||
|
||||
#### 8\. Python 2 is dead, long live Python 3
|
||||
|
||||
Python 2 will be [deprecated][9] on January 1, 2020 by python.org . While Debian does have Python 2.7 efforts are on to remove after moving all packages to Python 3 to remove it from the repo. This may happen either at Buster release or in a future point release but this is imminent. So Python developers are encouraged to move their code-base to be compatible with Python 3. At the moment of writing, both python2 and python3 are supported in Debian buster.
|
||||
|
||||
#### 9\. Mailman 3
|
||||
|
||||
Mailman3 is finally available in Debian. While [Mailman][10] has been further sub-divided into components. To install the whole stack, install mailman3-full to get all the components.
|
||||
|
||||
#### 10\. Any existing Postgresql databases used will need to be reindexed
|
||||
|
||||
Due to updates in glibc locale data, the way the information is sorted in put in text indexes will change hence it would be beneficial to reindex the data so no data corruption arises in near future.
|
||||
|
||||
#### 11\. Bash 5.0 by Default
|
||||
|
||||
You probably have already about the [new features in Bash 5.0][11], this version is already in Debian.
|
||||
|
||||
#### 12\. Debian implementing /usr/merge
|
||||
|
||||
An excellent freedesktop [primer][12] on what /usr/merge brings is already shared. Couple of things to note though. While Debian would like to do the whole transition, there is possibility that due to unforseen circumstances, some binaries may not be in a position to do the change. One point to note though, /var and /etc/ will be left alone so people who are using containers or cloud would not have to worry too much :)
|
||||
|
||||
#### 13\. Secure-boot support
|
||||
|
||||
With Buster RC1, Debian now has secure-boot support. Which means machines which have the secure-boot bit turned on in the machine should be easily able to install Debian on such machines. No need to disable or workaround Secure boot anymore :)
|
||||
|
||||
#### 14\. Calameres Live-installer for Debian-Live images
|
||||
|
||||
For Debian buster, Debian Live, Debian introduces [Calameres Installer][13] instead of plain old debian-installer. While the Debian-installer has lot many features than Calameres, for newbies Calameres provides a fresh alternative to install than debian-installer. Some screenshots from the installation process.
|
||||
|
||||
![Calamares Partitioning Stage][14]
|
||||
|
||||
As can be seen it is pretty easy to Install Debian under Calamares, only 5 stages to go through and you can have Debian installed at your end.
|
||||
|
||||
### Download Debian 10 Live Images (only for testing)
|
||||
|
||||
Don’t use it on production machines just yet. Try it on a test machine or a virtual machine.
|
||||
|
||||
You can get Debian 64-bit and 32 bit images from Debian Live [directory][15]. If you want the 64-bit look into 64-bit directory, if you want the 32-bit, you can look into the 32-bit directory.
|
||||
|
||||
[Debian 10 Buster Live Images][15]
|
||||
|
||||
If you upgrade from existing stable and something breaks, see if it is reported against the [upgrade-reports][16] psuedo-package using [reportbug][17] you saw the issue with. If the bug has not reported in the package then report it and share as much information as you can.
|
||||
|
||||
**In Conclusion**
|
||||
|
||||
While thousands of packages have been updated and it is virtually impossible to list them all. I have tired to list some of the major changes that you can look for in Debian buster. What do you think of it?
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/new-features-coming-to-debian-10-buster-release/
|
||||
|
||||
作者：[Shirish][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/shirish/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://wiki.debian.org/DebianBuster
|
||||
[2]: https://www.debian.org/
|
||||
[3]: https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures
|
||||
[4]: https://itsfoss.com/reasons-why-i-love-debian/
|
||||
[5]: https://wiki.debian.org/DebianArt/Themes/futurePrototype
|
||||
[6]: https://itsfoss.com/wp-content/uploads/2019/04/debian-buster-theme-800x450.png
|
||||
[7]: https://wiki.debian.org/AppArmor
|
||||
[8]: https://itsfoss.com/install-nodejs-ubuntu/
|
||||
[9]: https://www.python.org/dev/peps/pep-0373/
|
||||
[10]: https://www.list.org/
|
||||
[11]: https://itsfoss.com/bash-5-release/
|
||||
[12]: https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/
|
||||
[13]: https://calamares.io/about/
|
||||
[14]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/calamares-partitioning-wizard.jpg?fit=800%2C538&ssl=1
|
||||
[15]: https://cdimage.debian.org/cdimage/weekly-live-builds/
|
||||
[16]: https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=upgrade-reports;dist=unstable
|
||||
[17]: https://itsfoss.com/bug-report-debian/
|
||||
@ -1,66 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (8 environment-friendly open software projects you should know)
|
||||
[#]: via: (https://opensource.com/article/19/4/environment-projects)
|
||||
[#]: author: (Laura Hilliger https://opensource.com/users/laurahilliger)
|
||||
|
||||
8 environment-friendly open software projects you should know
|
||||
======
|
||||
Celebrate Earth Day by contributing to these projects dedicated to
|
||||
improving our environment.
|
||||
![][1]
|
||||
|
||||
For the last few years, I've been helping [Greenpeace][2] build its first fully open source software project, Planet 4. [Planet 4][3] is a global engagement platform where Greenpeace supporters and activists can interact and engage with the organization. The goal is to drive people to action on behalf of our planet. We want to invite participation and use people power to battle global issues like climate change and plastic pollution. Developers, designers, writers, contributors, and others who are looking for an open source way to support environmentalism are more than welcome to [get involved][4]!
|
||||
|
||||
Planet 4 is far from the only open source project focused on the environment. For Earth Day, I thought I'd share seven other open source projects that have our planet in mind.
|
||||
|
||||
**[Eco Hacker Farm][5]** works to support sustainable communities. It advises and supports projects combining hackerspaces/hackbases and permaculture living. The organization also has online software projects. Visit its [wiki][6] or reach out on [Twitter][7] to learn more about what Eco Hacker Farm is doing.
|
||||
|
||||
**[Public Lab][8]** is an open community and nonprofit organization that works to put science in the hands of citizens. Formed after the BP oil disaster in 2010, Public Lab works with open source to aid environmental exploration and investigation. It's a diverse community with lots of ways to [contribute][9].
|
||||
|
||||
A while back, Don Watkins, a community moderator here on Opensource.com, wrote about **[Open Climate Workbench][10]** , a project from the Apache Foundation. The [OCW][11] provides software to do climate modeling and evaluation, which can have all sorts of applications.
|
||||
|
||||
**[Open Source Ecology][12]** is a project that aims to improve how our economy functions. With an eye on environmental regeneration and social justice, the project seeks to redefine some of our dirty production and distribution techniques to create a more sustainable civilization.
|
||||
|
||||
Fostering collaboration around open source and big data tools to enable research in ocean, atmosphere, land, and climate, " **[Pangeo][13]** is first and foremost a community promoting open, reproducible, and scalable science." Big data can change the world!
|
||||
|
||||
**[**Leaflet**][14]** is a well-known open source JavaScript library. It can be used for all sorts of things, including environmentally friendly projects like the [Arctic Web Map][15], which allows scientists to accurately visualize and analyze the arctic region, a critical ability for climate research.
|
||||
|
||||
And of course, no list would be complete (not that this is a complete list!) without pointing to my friends at Mozilla. The **[Mozilla Science Lab][16]** community is, like all of Mozilla, fiercely open, and it's committed to bringing open source principles to the scientific community. Its projects and communities enable scientists to do the sorts of research our world needs to address some of the most pervasive environmental issues.
|
||||
|
||||
### How you can contribute
|
||||
|
||||
This Earth Day, make a six-month commitment to contribute some of your time to an open source project that helps fight climate change or otherwise encourages people to step up for Mother Earth. There must be scores of environmentally minded open source projects out there, so please leave your favorites in the comments!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/environment-projects
|
||||
|
||||
作者：[Laura Hilliger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/laurahilliger
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/world_hands_diversity.png?itok=zm4EDxgE
|
||||
[2]: http://www.greenpeace.org
|
||||
[3]: http://medium.com/planet4
|
||||
[4]: https://planet4.greenpeace.org/community/#partners-open-sourcers
|
||||
[5]: https://wiki.ecohackerfarm.org/start
|
||||
[6]: https://wiki.ecohackerfarm.org/
|
||||
[7]: https://twitter.com/EcoHackerFarm
|
||||
[8]: https://publiclab.org/
|
||||
[9]: https://publiclab.org/contribute
|
||||
[10]: https://opensource.com/article/17/1/apache-open-climate-workbench
|
||||
[11]: https://climate.apache.org/
|
||||
[12]: https://wiki.opensourceecology.org/wiki/Project_needs
|
||||
[13]: http://pangeo.io/
|
||||
[14]: https://leafletjs.com/
|
||||
[15]: https://webmap.arcticconnect.ca/#ac_3573/2/20.8/-65.5
|
||||
[16]: https://science.mozilla.org/
|
||||
@ -1,341 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How To Monitor Disk I/O Activity Using iotop And iostat Commands In Linux?)
|
||||
[#]: via: (https://www.2daygeek.com/monitor-disk-io-activity-using-iotop-iostat-command-in-linux/)
|
||||
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
|
||||
|
||||
How To Monitor Disk I/O Activity Using iotop And iostat Commands In Linux?
|
||||
======
|
||||
|
||||
Do you know what are the tools we can use for troubleshooting or monitoring real-time disk activity in Linux?
|
||||
|
||||
If **[Linux system performance][1]** gets slow down we may use **[top command][2]** to see the system performance.
|
||||
|
||||
It is used to check what are the processes are consuming high utilization on server.
|
||||
|
||||
It’s common for most of the Linux administrator.
|
||||
|
||||
It’s widely used by Linux administrator in the real world.
|
||||
|
||||
If you don’t see much difference in the process output still you have an option to check other things.
|
||||
|
||||
I would like to advise you to check `wa` status in the top output because most of the time the server performance will be degraded due to high I/O Read and Write on hard disk.
|
||||
|
||||
If it’s high or fluctuation, it could be a cause. So, we need to check I/O activity on hard drive.
|
||||
|
||||
We can monitory disk I/O statistics for all disks and file system in Linux system using `iotop` and `iostat` commands.
|
||||
|
||||
### What Is iotop?
|
||||
|
||||
iotop is a top-like utility for displaying real-time disk activity.
|
||||
|
||||
iotop watches I/O usage information output by the Linux kernel and displays a table of current I/O usage by processes or threads on the system.
|
||||
|
||||
It displays the I/O bandwidth read and written by each process/thread. It also displays the percentage of time the thread/process spent while swapping in and while waiting on I/O.
|
||||
|
||||
Total DISK READ and Total DISK WRITE values represent total read and write bandwidth between processes and kernel threads on the one side and kernel block device subsystem on the other.
|
||||
|
||||
Actual DISK READ and Actual DISK WRITE values represent corresponding bandwidths for actual disk I/O between kernel block device subsystem and underlying hardware (HDD, SSD, etc.).
|
||||
|
||||
### How To Install iotop In Linux?
|
||||
|
||||
We can easily install it with help of package manager since the package is available in all the Linux distributions repository.
|
||||
|
||||
For **`Fedora`** system, use **[DNF Command][3]** to install iotop.
|
||||
|
||||
```
|
||||
$ sudo dnf install iotop
|
||||
```
|
||||
|
||||
For **`Debian/Ubuntu`** systems, use **[APT-GET Command][4]** or **[APT Command][5]** to install iotop.
|
||||
|
||||
```
|
||||
$ sudo apt install iotop
|
||||
```
|
||||
|
||||
For **`Arch Linux`** based systems, use **[Pacman Command][6]** to install iotop.
|
||||
|
||||
```
|
||||
$ sudo pacman -S iotop
|
||||
```
|
||||
|
||||
For **`RHEL/CentOS`** systems, use **[YUM Command][7]** to install iotop.
|
||||
|
||||
```
|
||||
$ sudo yum install iotop
|
||||
```
|
||||
|
||||
For **`openSUSE Leap`** system, use **[Zypper Command][8]** to install iotop.
|
||||
|
||||
```
|
||||
$ sudo zypper install iotop
|
||||
```
|
||||
|
||||
### How To Monitor Disk I/O Activity/Statistics In Linux Using iotop Command?
|
||||
|
||||
There are many options are available in iotop command to check varies statistics about disk I/O.
|
||||
|
||||
Run the iotop command without any arguments to see each process or thread current I/O usage.
|
||||
|
||||
```
|
||||
# iotop
|
||||
```
|
||||
|
||||
[![][9]![][9]][10]
|
||||
|
||||
If you would like to check which process are actually doing IO then run the iotop command with `-o` or `--only` option.
|
||||
|
||||
```
|
||||
# iotop --only
|
||||
```
|
||||
|
||||
[![][9]![][9]][11]
|
||||
|
||||
**Details:**
|
||||
|
||||
* **`IO:`** It shows I/O utilization for each process, which includes disk and swap.
|
||||
* **`SWAPIN:`** It shows only the swap usage of each process.
|
||||
|
||||
|
||||
|
||||
### What Is iostat?
|
||||
|
||||
iostat is used to report Central Processing Unit (CPU) statistics and input/output statistics for devices and partitions.
|
||||
|
||||
The iostat command is used for monitoring system input/output device loading by observing the time the devices are active in relation to their average transfer rates.
|
||||
|
||||
The iostat command generates reports that can be used to change system configuration to better balance the input/output load between physical disks.
|
||||
|
||||
All statistics are reported each time the iostat command is run. The report consists of a CPU header row followed by a row of CPU statistics.
|
||||
|
||||
On multiprocessor systems, CPU statistics are calculated system-wide as averages among all processors. A device header row is displayed followed by a line of statistics for each device that is configured.
|
||||
|
||||
The iostat command generates two types of reports, the CPU Utilization report and the Device Utilization report.
|
||||
|
||||
### How To Install iostat In Linux?
|
||||
|
||||
iostat tool is part of sysstat package so, We can easily install it with help of package manager since the package is available in all the Linux distributions repository.
|
||||
|
||||
For **`Fedora`** system, use **[DNF Command][3]** to install sysstat.
|
||||
|
||||
```
|
||||
$ sudo dnf install sysstat
|
||||
```
|
||||
|
||||
For **`Debian/Ubuntu`** systems, use **[APT-GET Command][4]** or **[APT Command][5]** to install sysstat.
|
||||
|
||||
```
|
||||
$ sudo apt install sysstat
|
||||
```
|
||||
|
||||
For **`Arch Linux`** based systems, use **[Pacman Command][6]** to install sysstat.
|
||||
|
||||
```
|
||||
$ sudo pacman -S sysstat
|
||||
```
|
||||
|
||||
For **`RHEL/CentOS`** systems, use **[YUM Command][7]** to install sysstat.
|
||||
|
||||
```
|
||||
$ sudo yum install sysstat
|
||||
```
|
||||
|
||||
For **`openSUSE Leap`** system, use **[Zypper Command][8]** to install sysstat.
|
||||
|
||||
```
|
||||
$ sudo zypper install sysstat
|
||||
```
|
||||
|
||||
### How To Monitor Disk I/O Activity/Statistics In Linux Using sysstat Command?
|
||||
|
||||
There are many options are available in iostat command to check varies statistics about disk I/O and CPU.
|
||||
|
||||
Run the iostat command without any arguments to see complete statistics of the system.
|
||||
|
||||
```
|
||||
# iostat
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.45 0.02 16.47 0.12 0.00 53.94
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
nvme0n1 6.68 126.95 124.97 0.00 58420014 57507206 0
|
||||
sda 0.18 6.77 80.24 0.00 3115036 36924764 0
|
||||
loop0 0.00 0.00 0.00 0.00 2160 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 1093 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 1077 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with `-d` option to see I/O statistics for all the devices
|
||||
|
||||
```
|
||||
# iostat -d
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
nvme0n1 6.68 126.95 124.97 0.00 58420030 57509090 0
|
||||
sda 0.18 6.77 80.24 0.00 3115292 36924764 0
|
||||
loop0 0.00 0.00 0.00 0.00 2160 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 1093 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 1077 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with `-p` option to see I/O statistics for all the devices and their partitions.
|
||||
|
||||
```
|
||||
# iostat -p
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.42 0.02 16.45 0.12 0.00 53.99
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
nvme0n1 6.68 126.94 124.96 0.00 58420062 57512278 0
|
||||
nvme0n1p1 6.40 124.46 118.36 0.00 57279753 54474898 0
|
||||
nvme0n1p2 0.27 2.47 6.60 0.00 1138069 3037380 0
|
||||
sda 0.18 6.77 80.23 0.00 3116060 36924764 0
|
||||
sda1 0.00 0.01 0.00 0.00 3224 0 0
|
||||
sda2 0.18 6.76 80.23 0.00 3111508 36924764 0
|
||||
loop0 0.00 0.00 0.00 0.00 2160 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 1093 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 1077 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with `-x` option to see detailed I/O statistics for all the devices.
|
||||
|
||||
```
|
||||
# iostat -x
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.41 0.02 16.45 0.12 0.00 54.00
|
||||
|
||||
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz w/s wkB/s wrqm/s %wrqm w_await wareq-sz d/s dkB/s drqm/s %drqm d_await dareq-sz aqu-sz %util
|
||||
nvme0n1 2.45 126.93 0.60 19.74 0.40 51.74 4.23 124.96 5.12 54.76 3.16 29.54 0.00 0.00 0.00 0.00 0.00 0.00 0.31 30.28
|
||||
sda 0.06 6.77 0.00 0.00 8.34 119.20 0.12 80.23 19.94 99.40 31.84 670.73 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.13
|
||||
loop0 0.00 0.00 0.00 0.00 0.08 19.64 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
|
||||
loop1 0.00 0.00 0.00 0.00 0.40 12.86 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
|
||||
loop2 0.00 0.00 0.00 0.00 0.38 19.58 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
|
||||
```
|
||||
|
||||
Run the iostat command with `-d [Device_Name]` option to see I/O statistics of particular device and their partitions.
|
||||
|
||||
```
|
||||
# iostat -p [Device_Name]
|
||||
|
||||
# iostat -p sda
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.38 0.02 16.43 0.12 0.00 54.05
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
sda 0.18 6.77 80.21 0.00 3117468 36924764 0
|
||||
sda2 0.18 6.76 80.21 0.00 3112916 36924764 0
|
||||
sda1 0.00 0.01 0.00 0.00 3224 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with `-m` option to see I/O statistics with `MB` for all the devices instead of `KB`. By default it shows the output with KB.
|
||||
|
||||
```
|
||||
# iostat -m
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.36 0.02 16.41 0.12 0.00 54.09
|
||||
|
||||
Device tps MB_read/s MB_wrtn/s MB_dscd/s MB_read MB_wrtn MB_dscd
|
||||
nvme0n1 6.68 0.12 0.12 0.00 57050 56176 0
|
||||
sda 0.18 0.01 0.08 0.00 3045 36059 0
|
||||
loop0 0.00 0.00 0.00 0.00 2 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 1 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 1 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with certain interval then use the following format. In this example, we are going to capture totally two reports at five seconds interval.
|
||||
|
||||
```
|
||||
# iostat [Interval] [Number Of Reports]
|
||||
|
||||
# iostat 5 2
|
||||
|
||||
Linux 4.19.32-1-MANJARO (daygeek-Y700) Thursday 18 April 2019 _x86_64_ (8 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
29.35 0.02 16.41 0.12 0.00 54.10
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
nvme0n1 6.68 126.89 124.95 0.00 58420116 57525344 0
|
||||
sda 0.18 6.77 80.20 0.00 3118492 36924764 0
|
||||
loop0 0.00 0.00 0.00 0.00 2160 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 1093 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 1077 0 0
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
3.71 0.00 2.51 0.05 0.00 93.73
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
|
||||
nvme0n1 19.00 0.20 311.40 0.00 1 1557 0
|
||||
sda 0.20 25.60 0.00 0.00 128 0 0
|
||||
loop0 0.00 0.00 0.00 0.00 0 0 0
|
||||
loop1 0.00 0.00 0.00 0.00 0 0 0
|
||||
loop2 0.00 0.00 0.00 0.00 0 0 0
|
||||
```
|
||||
|
||||
Run the iostat command with `-N` option to see the LVM disk I/O statistics report.
|
||||
|
||||
```
|
||||
# iostat -N
|
||||
|
||||
Linux 4.15.0-47-generic (Ubuntu18.2daygeek.com) Thursday 18 April 2019 _x86_64_ (2 CPU)
|
||||
|
||||
avg-cpu: %user %nice %system %iowait %steal %idle
|
||||
0.38 0.07 0.18 0.26 0.00 99.12
|
||||
|
||||
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
|
||||
sda 3.60 57.07 69.06 968729 1172340
|
||||
sdb 0.02 0.33 0.00 5680 0
|
||||
sdc 0.01 0.12 0.00 2108 0
|
||||
2g-2gvol1 0.00 0.07 0.00 1204 0
|
||||
```
|
||||
|
||||
Run the nfsiostat command to see the I/O statistics for Network File System(NFS).
|
||||
|
||||
```
|
||||
# nfsiostat
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.2daygeek.com/monitor-disk-io-activity-using-iotop-iostat-command-in-linux/
|
||||
|
||||
作者：[Magesh Maruthamuthu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.2daygeek.com/author/magesh/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.2daygeek.com/category/monitoring-tools/
|
||||
[2]: https://www.2daygeek.com/linux-top-command-linux-system-performance-monitoring-tool/
|
||||
[3]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/
|
||||
[4]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[5]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[6]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/
|
||||
[7]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/
|
||||
[8]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/
|
||||
[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[10]: https://www.2daygeek.com/wp-content/uploads/2015/03/monitor-disk-io-activity-using-iotop-iostat-command-in-linux-1.jpg
|
||||
[11]: https://www.2daygeek.com/wp-content/uploads/2015/03/monitor-disk-io-activity-using-iotop-iostat-command-in-linux-2.jpg
|
||||
@ -1,98 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Tracking the weather with Python and Prometheus)
|
||||
[#]: via: (https://opensource.com/article/19/4/weather-python-prometheus)
|
||||
[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
|
||||
|
||||
Tracking the weather with Python and Prometheus
|
||||
======
|
||||
Create a custom Prometheus integration to keep track of the biggest
|
||||
cloud provider of all: Mother Earth.
|
||||
![Tree clouds][1]
|
||||
|
||||
Open source monitoring system [Prometheus][2] has integrations to track many types of time-series data, but if you want an integration that doesn't yet exist, it's easy to build one. An often-used example is a custom integration with a cloud provider that uses the provider's APIs to grab specific metrics. In this example, though, we will integrate with the biggest cloud provider of all: Earth.
|
||||
|
||||
Luckily, the US government already measures the weather and provides an easy API for integrations. Getting the weather forecast for the next hour at Red Hat headquarters is simple.
|
||||
|
||||
|
||||
```
|
||||
import requests
|
||||
HOURLY_RED_HAT = "<https://api.weather.gov/gridpoints/RAH/73,57/forecast/hourly>"
|
||||
def get_temperature():
|
||||
result = requests.get(HOURLY_RED_HAT)
|
||||
return result.json()["properties"]["periods"][0]["temperature"]
|
||||
```
|
||||
|
||||
Now that our integration with Earth is done, it's time to make sure Prometheus can understand what we are saying. We can use the [Prometheus Python library][3] to create a registry with one _gauge_ : the temperature at Red Hat HQ.
|
||||
|
||||
|
||||
```
|
||||
from prometheus_client import CollectorRegistry, Gauge
|
||||
def prometheus_temperature(num):
|
||||
registry = CollectorRegistry()
|
||||
g = Gauge("red_hat_temp", "Temperature at Red Hat HQ", registry=registry)
|
||||
g.set(num)
|
||||
return registry
|
||||
```
|
||||
|
||||
Finally, we need to connect this to Prometheus in some way. That depends a little on the network topology for Prometheus: whether it is easier for Prometheus to talk to our service, or whether the reverse is easier.
|
||||
|
||||
The first case is the one usually recommended, if possible, so we need to build a web server exposing the registry and then configure Prometheus to _scrape_ it.
|
||||
|
||||
We can build a simple web server with [Pyramid][4].
|
||||
|
||||
|
||||
```
|
||||
from pyramid.config import Configurator
|
||||
from pyramid.response import Response
|
||||
from prometheus_client import generate_latest, CONTENT_TYPE_LATEST
|
||||
def metrics_web(request):
|
||||
registry = prometheus_temperature(get_temperature())
|
||||
return Response(generate_latest(registry),
|
||||
content_type=CONTENT_TYPE_LATEST)
|
||||
config = Configurator()
|
||||
config.add_route('metrics', '/metrics')
|
||||
config.add_view(metrics_web, route_name='metrics')
|
||||
app = config.make_wsgi_app()
|
||||
```
|
||||
|
||||
This can be run with any Web Server Gateway Interface (WSGI) server. For example, we can use **python -m twisted web --wsgi earth.app** to run it, assuming we put the code in **earth.py**.
|
||||
|
||||
Alternatively, if it is easier for our code to connect to Prometheus, we can push it to Prometheus's [Push gateway][5] periodically.
|
||||
|
||||
|
||||
```
|
||||
import time
|
||||
from prometheus_client import push_to_gateway
|
||||
def push_temperature(url):
|
||||
while True:
|
||||
registry = prometheus_temperature(get_temperature())
|
||||
push_to_gateway(url, "temperature collector", registry)
|
||||
time.sleep(60*60)
|
||||
```
|
||||
|
||||
The URL is the one for the Push gateway; it often ends in **:9091**.
|
||||
|
||||
Good luck building your own custom Prometheus integration so you can track all the things!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/weather-python-prometheus
|
||||
|
||||
作者：[Moshe Zadka ][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/moshez
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life_tree_clouds.png?itok=b_ftihhP (Tree clouds)
|
||||
[2]: https://prometheus.io/
|
||||
[3]: https://github.com/prometheus/client_python
|
||||
[4]: https://trypyramid.com/
|
||||
[5]: https://github.com/prometheus/pushgateway
|
||||
@ -1,147 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Four Methods To Check The Default Gateway Or Router IP Address In Linux?)
|
||||
[#]: via: (https://www.2daygeek.com/check-find-default-gateway-or-router-ip-address-in-linux/)
|
||||
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
|
||||
|
||||
Four Methods To Check The Default Gateway Or Router IP Address In Linux?
|
||||
======
|
||||
|
||||
Your default gateway is the IP address of your router that you should aware of that.
|
||||
|
||||
Typically this is automatically detected by your operating system during installation, if not then you may need to change it.
|
||||
|
||||
If your system not able to ping self then probable it could be a gateway issue and you have to fix it.
|
||||
|
||||
This might happen if you have multiple network adapters or routers on the network.
|
||||
|
||||
A gateway is a router that acts as an access point to passes network data from one networks to another networks.
|
||||
|
||||
The below articles will help you to gather some other information which is similar to this topic.
|
||||
|
||||
* **[9 Methods To Check Your Public IP Address In Linux Command Line][1]**
|
||||
* **[How To Enable (UP) And Disable (DOWN) A Network Interface Port (NIC) In Linux?][2]**
|
||||
|
||||
|
||||
|
||||
This can be done using below Four commands.
|
||||
|
||||
* **`route Command:`** route command is used to show and manipulate the IP routing table.
|
||||
* **`ip Command:`** IP command is similar to ifconfig, which is very familiar for assigning Static IP Address, Route & Default Gateway, etc.,.
|
||||
* **`netstat Command:`** netstat (“network statistics”) is a command-line tool that displays network connections related information (both incoming and outgoing) such as routing tables, masquerade connections, multicast memberships and a number of network interface
|
||||
* **`routel Command:`** routel command is used to list routes with pretty output format.
|
||||
|
||||
|
||||
|
||||
### 1) How To Check The Default Gateway Or Router IP Address In Linux Using route Command?
|
||||
|
||||
route command is used to show and manipulate the IP routing table.
|
||||
|
||||
Its primary use is to set up static routes to specific hosts or networks via an interface once the interface was configured.
|
||||
|
||||
When the add or del options are used, route modifies the routing tables. Without these options, route displays the current contents of the routing tables.
|
||||
|
||||
```
|
||||
# route
|
||||
or
|
||||
# route -n
|
||||
|
||||
Kernel IP routing table
|
||||
Destination Gateway Genmask Flags Metric Ref Use Iface
|
||||
default www.routerlogin 0.0.0.0 UG 600 0 0 wlp8s0
|
||||
192.168.1.0 0.0.0.0 255.255.255.0 U 600 0 0 wlp8s0
|
||||
```
|
||||
|
||||
### 2) How To Check The Default Gateway Or Router IP Address In Linux Using ip Command?
|
||||
|
||||
**[IP command][3]** is similar to ifconfig, which is very familiar for assigning Static IP Address, Route & Default Gateway, etc.,.
|
||||
|
||||
ifconfig command was deprecated due to no maintenance since so many years, even though it is still available on most Linux distributions.
|
||||
|
||||
ifconfig command has been replaced by IP command which is very powerful and performing several network administration tasks with one command.
|
||||
|
||||
IP command utility bundled with iproute2 package. By default iproute2 utility pre-installed all the major Linux distribution.
|
||||
|
||||
If no, you can install it by issuing iproute2 on your terminal with help of package manager.
|
||||
|
||||
```
|
||||
# ip r
|
||||
or
|
||||
# ip route
|
||||
or
|
||||
# ip route show
|
||||
|
||||
default via 192.168.1.1 dev wlp8s0 proto dhcp metric 600
|
||||
192.168.1.0/24 dev wlp8s0 proto kernel scope link src 192.168.1.6 metric 600
|
||||
```
|
||||
|
||||
### 3) How To Check The Default Gateway Or Router IP Address In Linux Using netstat Command?
|
||||
|
||||
netstat stands for Network Statistics, is a command-line tool that displays network connections related information (both incoming and outgoing) such as routing tables, masquerade connections, multicast memberships and a number of network interface.
|
||||
|
||||
It lists out all the tcp, udp socket connections and the unix socket connections.
|
||||
|
||||
It is used for diagnosing network problems in the network and to determine the amount of traffic on the network as a performance measurement.
|
||||
|
||||
```
|
||||
# netstat -r
|
||||
|
||||
Kernel IP routing table
|
||||
Destination Gateway Genmask Flags MSS Window irtt Iface
|
||||
default www.routerlogin 0.0.0.0 UG 0 0 0 wlp8s0
|
||||
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlp8s0
|
||||
```
|
||||
|
||||
### 4) How To Check The Default Gateway Or Router IP Address In Linux Using routel Command?
|
||||
|
||||
It used to list routes with pretty output format. These programs are a set of helper scripts you can use instead of raw iproute2 commands.
|
||||
|
||||
The routel script will list routes in a format that some might consider easier to interpret then the ip route list equivalent.
|
||||
|
||||
The routef script does not take any arguments and will simply flush the routing table down the drain. Beware! This means deleting all routes which will make your network unusable!
|
||||
|
||||
```
|
||||
# routel
|
||||
target gateway source proto scope dev tbl
|
||||
default 192.168.1.1 dhcp wlp8s0
|
||||
192.168.1.0/ 24 192.168.1.6 kernel link wlp8s0
|
||||
127.0.0.0 broadcast 127.0.0.1 kernel link lo local
|
||||
127.0.0.0/ 8 local 127.0.0.1 kernel host lo local
|
||||
127.0.0.1 local 127.0.0.1 kernel host lo local
|
||||
127.255.255.255 broadcast 127.0.0.1 kernel link lo local
|
||||
192.168.1.0 broadcast 192.168.1.6 kernel link wlp8s0 local
|
||||
192.168.1.6 local 192.168.1.6 kernel host wlp8s0 local
|
||||
192.168.1.255 broadcast 192.168.1.6 kernel link wlp8s0 local
|
||||
::1 kernel lo
|
||||
fe80::/ 64 kernel wlp8s0
|
||||
::1 local kernel lo local
|
||||
fe80::ad00:2f7e:d882:5add local kernel wlp8s0 local
|
||||
ff00::/ 8 wlp8s0 local
|
||||
```
|
||||
|
||||
If you would like to print only default gateway then use the following format.
|
||||
|
||||
```
|
||||
# routel | grep default
|
||||
default 192.168.1.1 dhcp wlp8s0
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.2daygeek.com/check-find-default-gateway-or-router-ip-address-in-linux/
|
||||
|
||||
作者：[Magesh Maruthamuthu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.2daygeek.com/author/magesh/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.2daygeek.com/check-find-server-public-ip-address-linux/
|
||||
[2]: https://www.2daygeek.com/enable-disable-up-down-nic-network-interface-port-linux-using-ifconfig-ifdown-ifup-ip-nmcli-nmtui/
|
||||
[3]: https://www.2daygeek.com/ip-command-configure-network-interface-usage-linux/
|
||||
@ -1,75 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (lujun9972)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (3 Emacs modes for taking notes)
|
||||
[#]: via: (https://opensource.com/article/18/7/emacs-modes-note-taking)
|
||||
[#]: author: (Scott Nesbitt https://opensource.com/users/scottnesbitt)
|
||||
|
||||
用来记笔记的三个 Emacs modes
|
||||
======
|
||||
借助这些 Emacs mode 轻松记录信息。
|
||||
|
||||
|
||||
|
||||
不管你从事哪种工作，你都无可避免地需要记笔记。而且可能还不是一点点。现在这年头，大家都开始以数字的形式来记笔记了。
|
||||
|
||||
开源软件爱好者有多种途径来以电子的方式记下他们的创意，想法和研究过程。你可以使用 [网页工具 ][[1]]。你可以使用 [桌面应用 ][2]。或者，你也可以 [使用命令行工具 ][3]。
|
||||
|
||||
如果你使用 [Emacs][4]( 伪装成文本编辑器的强力操作系统)，有多个 mode 可以帮你有效地记录笔记。我们这里列举三个例子。
|
||||
|
||||
### Deft
|
||||
|
||||
|
||||
在少数情况下，我被迫需要使用 Mac，有一个工具是我不能缺少的：[nvALT][5] 笔记应用。[Deft mode][6] 为 Emacs 带来了 nvALT 式的体验。
|
||||
|
||||
Deft 将你的笔记以文本文件的形式存储在电脑中的某个文件夹中。当你进入 Deft mode，你会看到一系列的笔记及其摘要。这些摘要其实就是文本文件的第一行。若第一行是 Markdown，LaTeX，甚至 Emacs Org mode 格式的话，Deft 会忽略掉这些格式而只显示文本内容。
|
||||
|
||||
要打开笔记，只需要向下滚动到该笔记的位置然后按下回车即可。然而 Deft 不仅仅只是这样。根据 Deft 开发者 Jason Blevins 的说法，它的 /主要操作时搜索和过滤/。
|
||||
Deft 的实现方式简单而有效。输入关键字然后 Deft 会只显示标题中包含关键字的笔记。这在你要从大量笔记中找到某条笔记时非常有用。
|
||||
|
||||
### Org mode
|
||||
|
||||
|
||||
如果本文没有包含 [Org mode][7] 的话，那么我可能会被人所诟病。为什么？它可以说是 Emacs 中最灵活、使用最广泛的记录笔记的方式了。以正确的方式使用它，Org mode 可以极大地增强记笔记的能力。
|
||||
|
||||
Org mode 的主要优势在于它组织笔记的方式。在 Org mode 中，一个笔记文件被组织成一个巨大的大纲。每个章节就是大纲里的一个节点，你可以对它进行展开和折叠。这些章节又可以有子章节，这些子章节也可以暂开和折叠。这不仅使你一次只关注于某个章节，而且可以让你浏览整个大纲。
|
||||
|
||||
你可以在多个章节之间 [进行互联 ][8]，无需通过剪切和复制就能快速移动章节，以及 [附加文件 ][9] 到笔记中。Org mode 支持带格式的字符和表格。如果你需要转换笔记到其他格式，Org mode 也有大量的[导出选项 ][10]。
|
||||
|
||||
|
||||
### Howm
|
||||
|
||||
|
||||
|
||||
当我使用 Emacs 已经成为一种习惯时，[howm][11] 马上就成为我严重依赖的 mode 之一了。虽然我特别喜欢使用 Org mode，但 howm 依然占有一席之地。
|
||||
|
||||
Howm 就好像时一个小维基似得。你可以创建笔记和任务列表，还能在他们之间创建链接。通过输入或点击某个链接，你可以在笔记之间跳转。如果你需要，还可以使用关键字为笔记添加标签。不仅如此，你可以对笔记进行搜索、排序和合并。
|
||||
|
||||
Howm 不是最漂亮的 Emacs mode，它也没有最好的用户体验。它需要你花一点时间来适应它。而一旦你适应了它，记录和查找笔记就是轻而易举的事情了。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/7/emacs-modes-note-taking
|
||||
|
||||
作者：[Scott Nesbitt][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/scottnesbitt
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/alternatives/evernote
|
||||
[2]: https://opensource.com/life/16/9/4-desktop-note-taking-applications
|
||||
[3]: https://opensource.com/article/18/3/command-line-note-taking-applications
|
||||
[4]: https://www.gnu.org/software/emacs/
|
||||
[5]: http://brettterpstra.com/projects/nvalt/
|
||||
[6]: https://jblevins.org/projects/deft/
|
||||
[7]: https://orgmode.org/
|
||||
[8]: https://orgmode.org/org.html#Hyperlinks
|
||||
[9]: https://orgmode.org/org.html#Attachments
|
||||
[10]: https://orgmode.org/org.html#Exporting
|
||||
[11]: https://howm.osdn.jp/
|
||||
@ -1,202 +0,0 @@
|
||||
Linux 初学者: 移动文件
|
||||
=====================
|
||||
|
||||
|
||||
|
||||
在之前的该系列的部分中，[你学习了有关目录][1]和[访问目录的权限是如何工作的][2]。你在这些文章中学习的大多数都可应用于文件，除了如何让一个文件变得可执行。
|
||||
|
||||
因此让我们在开始之前先解决这个问题。
|
||||
|
||||
### 不需要 .exe 文件
|
||||
|
||||
在其他操作系统中，一个文件的性质通常由它的后缀决定。如果一个文件有一个 _.jpg_ 扩展，操作系统会认为它是一幅图像；如果它以 _.wav_ 结尾， 它是一个音频文件； 如果它在文件名末尾 以 _.exe_ 结尾， 它就是一个你可以执行的程序。
|
||||
|
||||
这导致了严重的问题，像木马伪装成文件。幸运的是，在 Linux 下事务不是这样运行的。可以确定的是，你可能会看到有些可执行文件是以 _.sh_ 结尾暗示他们是可执行的脚本，但是这大部分是为了利于人类识别的文件，和你使用 `ls --color` 的方式相同，可执行文件的名字以亮绿色显示。
|
||||
|
||||
事实上大多数应用根本没有扩展。决定一个文件是否是一个真正程序的是 _x_ （用于_可执行的_） 位。你可以通过运行以下命令使任何文件变得可执行：
|
||||
```
|
||||
chmod a+x some_program
|
||||
|
||||
```
|
||||
|
||||
而不管它的扩展名是什么或者是否存在。在上面命令中的 `x` 设置了 _x_ 位，`a` 说明你为_所有_用户设置它。你同样可以为一组用户设置成拥有这个文件 （`g+x`），或者设置为只有一个用户，拥有着 （`u+x`）。
|
||||
|
||||
尽管我们会在该系列之后部分包含从命令行创建和运行脚本的内容，并学习到你可以通过输入它的路径并在结尾加上程序名的方式运行一个程序：
|
||||
```
|
||||
path/to/directory/some_program
|
||||
|
||||
```
|
||||
|
||||
或者，如果你当前在相同目录，你可以使用：
|
||||
```
|
||||
./some_program
|
||||
|
||||
```
|
||||
|
||||
还有其他方式可以使你的程序在目录树的任意位置运行 （提示：查询 `$PATH` 环境变量），但是当我们讨论 shell 脚本的时候你会读到这些。
|
||||
|
||||
### 复制，移动，链接
|
||||
|
||||
明显地，有更多的方式来从命令行修改和处理文件，而不仅仅是处理它们的权限。当你试图打开一个不存在的文件是，大多数应用会创建一个新文件。如果 _test.txt_ 当前并不存在，下列命令
|
||||
|
||||
```
|
||||
nano test.txt
|
||||
|
||||
```
|
||||
|
||||
```
|
||||
vim test.txt
|
||||
|
||||
```
|
||||
|
||||
（[nano][3] 和 [vim][4] 是流行的命令行文本编辑器） 都将为你创建一个空的 _test.txt_ 文件来编辑。
|
||||
|
||||
你可以通过 “触摸” （touching, 触摸）来创建一个空的文件：
|
||||
```
|
||||
touch test.txt
|
||||
|
||||
```
|
||||
|
||||
会创建一个文件，但是不会在任何应用中打开它。
|
||||
|
||||
你可以使用 `cp` 来拷贝一个文件到另一个位置或者使用一个不同的名字：
|
||||
```
|
||||
cp test.txt copy_of_test.txt
|
||||
|
||||
```
|
||||
|
||||
你也可以拷贝一堆文件：
|
||||
```
|
||||
cp *.png /home/images
|
||||
|
||||
```
|
||||
|
||||
上面的命令拷贝当前目录下的所有 PNG 文件到相对你的 home 目录下的 _images/_ 目录。在你尝试之前 _images/_ 目录必须存在， 不然 `cp` 将显示一个错误。同样的，警惕，当你复制一个文件到一个已经包含相同名字的文件的目录时， `cp` 会静默地用新文件覆盖老的文件。
|
||||
|
||||
你可以使用
|
||||
```
|
||||
cp -i *.png /home/images
|
||||
|
||||
```
|
||||
|
||||
如果你想要 `cp` 命令在有任何危险时警告你 （`-i` 选项代表 _交互式的_）。
|
||||
|
||||
你同样可以复制整个目录，但是为了做到这样，你需要 `-r` 选项：
|
||||
```
|
||||
cp -rv directory_a/ directory_b
|
||||
|
||||
```
|
||||
|
||||
`-r` 选项代表 _递归_，意味着 `cp` 会向下探索目录 _directory_a_，复制所有的文件和子目录下内部包含的。我个人喜欢包含 `-v` 选项，因为它使 `cp` 冗长而啰嗦，意味着它会显示你当前它正在做什么而不是仅仅静默的复制然后存在。
|
||||
|
||||
`mv` 命令移动东西。也就是说，它移动文件从一个位置到另一个位置。最简单的形式，`mv` 表现的更像 `cp`：
|
||||
```
|
||||
mv test.txt new_test.txt
|
||||
|
||||
```
|
||||
|
||||
上面的命令使 _new_test.txt_ 出现， _test.txt_ 消失。
|
||||
```
|
||||
mv *.png /home/images
|
||||
|
||||
```
|
||||
|
||||
移动当前目录下所有的 PNG 文件到相对于你的 home 目录的 _images/_ 目录。同样的你必须小心你没有意外的覆盖已存在的文件。使用
|
||||
```
|
||||
mv -i *.png /home/images
|
||||
|
||||
```
|
||||
|
||||
如果你想站在安全的角度，你可以使用与 `cp` 相同的方式。
|
||||
|
||||
除了移动与拷贝的不同外，另一个 `mv` 和 `cp` 之间的不同是当你移动目录时:
|
||||
```
|
||||
mv directory_a/ directory_b
|
||||
|
||||
```
|
||||
|
||||
不需要添加递归的标志。这是因为你实际做的是重命名一个目录，与第一个例子相同，你做的是重命名文件。实际上，即使你 “移动” 一个文件从一个目录到另一个目录，只要两个目录在相同的存储设备和分区，你就是在重命名文件。
|
||||
|
||||
你可以做一个实验来证明。 `time` 是一个工具来让你测量一个命令花费多久来执行。找一个非常大的文件，可以是几百 MBs 甚至 几 GBs （例如一个长视频），像下方这样尝试拷贝到另一个目录：
|
||||
```
|
||||
$ time cp hefty_file.mkv another_directory/
|
||||
real 0m3,868s
|
||||
user 0m0,016s
|
||||
sys 0m0,887s
|
||||
|
||||
```
|
||||
|
||||
黑体是你必须输入命令行的，下面是 `time` 的输出。需要关注的是第一行， _real_ 时间。它花费了几乎 4 秒来拷贝 355 MBs 的 _hefty_file.mkv_ 到 _another_directory/_ 目录。
|
||||
|
||||
现在让我们尝试移动它：
|
||||
```
|
||||
$ time mv hefty_file.mkv another_directory/
|
||||
real 0m0,004s
|
||||
user 0m0,000s
|
||||
sys 0m0,003s
|
||||
|
||||
```
|
||||
|
||||
移动几乎是瞬时的！这是违反直觉的，因为看起来 `mv` 必须复制这个文件然后删除原来的。这是 `mv` 对比 `cp` 命令必须做的两件事。但是，实际上，`mv` 扩了 1000 倍。
|
||||
|
||||
这是因为文件系统结构中，它的所有目录树，只为了让用户便利而存在。在每个分区的开始，有一个称作 _分区表_ 的东西告诉操作系统在实际的物理磁盘上去哪找每个文件。在磁盘上，数据没有分为目录甚至是文件。[作为替代的是轨道，扇区和簇][5]。当你在相同分区 “移动” 一个文件时，操作系统实际做的仅仅是在分区表中改变了那个文件的入口，但它仍然指向磁盘上相同的簇信息。
|
||||
|
||||
是的！移动是一个谎言！至少在相同分区下是。如果你试图移动一个文件到一个不同的分区或者不同的设备， `mv` 仍然很快，但可以察觉到它比在相同分区下移动文件慢了。这是因为实际上发生了复制和清除数据。
|
||||
|
||||
### 重命名
|
||||
|
||||
有几个不同的命令行 `rename` 工具。没有一个像 `cp` 和 `mv` 那样固定并且他们工作的方式都有一点不同。他们相同的一点是他们被用来改变文件名的部分。
|
||||
|
||||
在 Debian 和 Ubuntu 中， 默认的 `rename` 工具使用 [正则表达式][6] （字符组成的字符串图案）来大量的改变目录中的文件。命令：
|
||||
```
|
||||
rename 's/\.JPEG$/.jpg/' *
|
||||
|
||||
```
|
||||
|
||||
将改变所有扩展为 _JPEG_ 的文件为 _jpg_ 。文件 _IMG001.JPEG_ 变成 _IMG001.jpg_， _my_pic.JPEG_ 变成 _my_pic.jpg_ ， 等等。
|
||||
|
||||
另一个 `rename` 版本默认在 Manjaro 上可获得，一个 Arch 的衍生版，更简单，但是可能没有那么强大：
|
||||
``` rename .JPEG .jpg *
|
||||
|
||||
```
|
||||
|
||||
这和你之前看到的上面做相同的重命名操作。在这个版本，`.JPEG` 是你想改变的字符组成的字符串，`.jpg` 是你想要改变成为的，`*` 表示当前目录下的所有文件。
|
||||
|
||||
基本原则是如果你所做的仅仅是重命名一个文件或者目录，你最好用 `mv`，这是因为 `mv` 在所有分发版上都是可靠一致的。
|
||||
|
||||
### 了解更多
|
||||
|
||||
查看 `mv` 和 `cp` 的 man 页面了解更多。运行
|
||||
```
|
||||
man cp
|
||||
|
||||
```
|
||||
|
||||
或者
|
||||
```
|
||||
man mv
|
||||
|
||||
```
|
||||
|
||||
来阅读这些命令自带的所有选项，这些使他们使用起来更强大和安全。
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/2018/8/linux-beginners-moving-things-around
|
||||
|
||||
作者：[Paul Brown][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.linux.com/users/bro66
|
||||
[1]: https://www.linux.com/blog/learn/2018/5/manipulating-directories-linux
|
||||
[2]: https://www.linux.com/blog/learn/intro-to-linux/2018/7/users-groups-and-other-linux-beasts-part-2
|
||||
[3]: https://www.nano-editor.org/
|
||||
[4]: https://www.vim.org/
|
||||
[5]: https://en.wikipedia.org/wiki/Disk_sector
|
||||
[6]: https://en.wikipedia.org/wiki/Regular_expression
|
||||
|
||||
|
||||
169
translated/tech/20190401 What is 5G- How is it better than 4G.md
Normal file
169
translated/tech/20190401 What is 5G- How is it better than 4G.md
Normal file
@ -0,0 +1,169 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (What is 5G? How is it better than 4G?)
|
||||
[#]: via: (https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html#tk.rss_all)
|
||||
[#]: author: (Josh Fruhlinger https://www.networkworld.com/author/Josh-Fruhlinger/)
|
||||
|
||||
什么是 5G？它如何比 4G 更快？
|
||||
==========================
|
||||
|
||||
### 5G 网络将使无限网络吞吐量提高 10 倍并且能够替代有线宽带。但是它们什么时候能够投入使用呢，为什么 5G 和物联网如此紧密地联系在一起呢？
|
||||
|
||||
![Thinkstock][1]
|
||||
|
||||
[5G 无线][2] 是一个概括的术语，用来描述一系列更快的无线网络的标准和技术，理想上比 4G 快了 20 倍并且延迟降低了 120 倍，为物联网的发展和对新高带宽应用的支持奠定了基础。
|
||||
|
||||
## 什么是 5G？科技还是流行词？
|
||||
|
||||
技术在世界范围内完全发挥它的潜能需要数年时间，但同时当今一些 5G 网络服务已经投入使用。5G 不仅是一个技术术语，也是一个营销术语，并不是市场上的所有 5G 服务是标准的。
|
||||
|
||||
**[来自世界移动大会：[The time of 5G is almost here][3].]**
|
||||
|
||||
## 5G 速度 vs 4G
|
||||
|
||||
无线技术的每一代，最大的呼吁是增加速度。5G 网络潜在的的峰值下载速度达到[20 Gbps，一般在 10 Gbps][4]。这不仅仅是比当前 4G 网络更快，4G 目前峰值大约 1 Gbps，并且比更多家庭的有线网络连接更快。5G 提供的网络速度能够与光纤一较高下。
|
||||
|
||||
吞吐量不是 5G 仅有的速度提升；它还有的特点是极大降低了网络延迟*。* 这是一个重要的区分：吞吐量用来测量花费多久来下载一个大文件，而延迟由网络瓶颈决定，延迟在来回的沟通中减慢了响应速度。
|
||||
|
||||
延迟很难量化，因为它在无数的网络状态中变化，但是 5G 网络在理想情况下有能力使延迟率在 1 ms 内。总的来说，5G 延迟将比 4G 降低 60 到 120 倍。这会使很多应用变得可能，例如当前虚拟现实的延迟使它变得不实际。
|
||||
|
||||
## 5G 技术
|
||||
|
||||
5G 技术的基础有一系列标准定义，在过去的 10 年里一直在研究更好的部分。这些里面最重要的是 5G New Radio，或者 5G NR*，* 由 3GPP（一个为移动电话开发协议的标准化组织） 组织标准化。5G NR 规定了很多 5G 设备操作的方式，于 2018 年 7 月 完成终版。
|
||||
|
||||
**[[从 PluralSight 上移动设备管理的课程并且学习如何在你的公司在不降低用户体验的情况下保护设备][6]]**
|
||||
|
||||
很多独特的技术同时出现来尽可能地提升 5G 的速度并降低延迟，下面是一些重要的。
|
||||
|
||||
## 毫米波
|
||||
|
||||
5G 网络大部分使用在 30 到 300 GHz 范围的频率。（正如名称一样，这些频率的波长在 1 到 10 毫米之间）这些高频范围能够[在每个时间单元比低频信号携带更多的信息][7]，4G 当前使用的就是通常频率在 1 GHz 以下的低频信号，或者 WiFi，最高 6 GHz。
|
||||
|
||||
毫米波技术传统上是昂贵并且难于部署的。科技进步已经克服了这些困难，这也是 5G 在如今成为了可能。
|
||||
|
||||
## 小的单元
|
||||
|
||||
毫米波传输的一个缺点是当他们传输通过物理对象的时候更容易被干扰。
|
||||
|
||||
为了克服这些，5G 基础设施的模型将不同于 4G。替代了大的移动天线桅杆，我们开始接受作为景观的一部分，5G 网络将由[穿越城市大概间距 250 米的更小的基站]提供支持，创建更小的服务区域。
|
||||
|
||||
## 大量的 MIMO
|
||||
|
||||
尽管 5G 基站比 4G 的对应部分小多了，但他们却打包了更多的天线。这些天线是[多输入多输出的（MIMO）][9]，意味着在相同的数据信道能够同时处理多个双向会话。5G 网络能够处理比 4G 网络超过 20 倍的会话。
|
||||
|
||||
大量的 MIMO 保证了[基站容量限制下的彻底的提升]，允许单个基站承载更多的设备会话。这就是 5G 可能推动物联网更广泛应用的原因。理论上，更多的网络连接的无限设备能够部署在相同的空间而不会使网络被压垮。
|
||||
|
||||
## 波束成形
|
||||
|
||||
确保所有的会话来回地到达正确的地方是比较棘手的，尤其是前面提到的毫米波信号的干涉问题。为了克服这些问题，5G 基站部署了更高级的波束技术，使用建设性和破坏性的无线电干扰来使信号有向而不是广播。这在一个特定的方向上有效地加强了信号强度和范围。
|
||||
|
||||
## 5G 可获得性
|
||||
|
||||
第一个 5G 商用网络 [2018 年 5 月在卡塔尔推出][12]。自那以后，网络已经扩展到全世界，从阿根廷到越南。[Lifewire 有一个不错的，经常更新的列表][13].
|
||||
|
||||
牢记一点的是，尽管这样，目前不是所有的 5G 网络都履行了所有的技术承诺。一些早期的 5G 产品依赖于现有的 4G 基础设施，减少了可以获得的潜在速度；其他服务为了市场目的标榜 5G 但是并不符合标准。仔细观察美国无限运营商的产品都会表现出一些陷阱。
|
||||
|
||||
## 无线运营商和 5G
|
||||
|
||||
技术上讲，5G 服务如今在美国已经可获得了。但声明中包含的注意事项因运营商而异，表明 5G 普及之前还有很长的路要走。
|
||||
|
||||
Verizon 可能是早期 5G 最大的推动者。它宣告到 2018 年 10 月 将有 4 个城市成为 [5G 家庭][14]的一部分， 一项需要你的其他设备通过 WiFi 来连接特定的 5G 热点，由热点连接到网络服务。
|
||||
|
||||
Verizon 计划四月在 Minneapolis 和 Chicago 首次展示 5G 移动服务，该服务将在这一年内传播到其他城市。访问 5G 网络将会花费消费者每月额外的费用加上购买能够实际访问 5G 的手机花费（稍后会详细介绍）。作为附加，Verizon 的部署被称作 [5G TF][16]，实际上不符合 5G NR 的标准。
|
||||
|
||||
AT&T [声明在 2018 年 12 月将有美国的 12 个城市可以使用 5G][17]，在 2019 年的末尾将增加 9 个城市，但最终在这些城市里，只有商业区能够访问。为了访问 5G 网络，需要一个特定的 Netgear 热点来连接到 5G 服务，然后为手机和其他设备提供一个 Wi-Fi 信号。
|
||||
|
||||
与此同时，AT&T 也在推出 4G 网络的速度提升计划，被成为 5GE，即使这些提升和 5G 网络没有关系。（[这会向后兼容][18]。）
|
||||
|
||||
Sprint 将在 2019 年 5 月之前在四个城市提供 5G 服务，在年末将有更多。但是 Sprint 的 5G 产品充分利用了 MIMO 单元，他们[没有使用毫米波信道][19]，意味着 Sprint 的用户不会看到像其他运营商一样的速度提升。
|
||||
|
||||
T-Mobile 追求一个相似的模型，它[在 2019 年年底之前不会推出 5G 服务][20]因为他们没有手机能够连接到它。
|
||||
|
||||
一个障碍可能阻止 5G 速度的迅速传播是需要铺开所有这些小的单元基站。他们小的尺寸和较低的功耗需求使它们技术上比 4G 技术更容易部署，但这不意味着它能够很简单的使政府和财产拥有者信服来到处安装一堆基站。Verizon 实际上建立了[向本地民选官员请愿的网站][21]来加速 5G 基站的部署。
|
||||
|
||||
## ** 5G 手机：何时可获得？何时可以买？**
|
||||
|
||||
第一部声称为 5G 手机的是 Samsung Galaxy S10 5G，将在 2019 年夏末首发。你可以从 Verizon 订阅一个“[Moto Mod][22]”，用来[转换 Moto Z3 手机为 5G 兼容设备][23]。
|
||||
|
||||
但是除非你不能忍受作为一个早期使用者的诱惑，你会希望再等待一下；一些奇怪和隐约的关于运营商的问题意味着可能你的手机[不兼容你的运营商的整个 5G 网络][24]。
|
||||
|
||||
一个可能令你吃惊的落后者是苹果：分析者坚信最早直到 2020 年以前 iPhone 不会与 5G 兼容。但这符合该公司的特点；苹果在 2012 年末也落后于三星发布兼容 4G 的手机。
|
||||
|
||||
不可否认，5G 洪流已经到来。5G 兼容的设备[在 2019 年统治了巴塞罗那世界移动大会][3]，因此期待视野里有更多的选择。
|
||||
|
||||
## 为什么人们已经在讨论 6G 了？
|
||||
|
||||
一些专家说缺点是[5G 不能够达到延迟和可靠性的目标][27]。这些完美主义者已经在探寻 6G，来试图解决这些缺点。
|
||||
|
||||
这是一个[研究新的能够融入 6G 技术的小组]，它们自称
|
||||
|
||||
The Center for Converged TeraHertz Communications and Sensing （ComSenTer）。根据说明，他们努力让每个设备的带宽达到 100Gbps。
|
||||
|
||||
除了增加可靠性，还突破了可靠性并增加速度，6G 同样试图允许上千的并发连接。如果成功的话，这个特点将帮助物联网设备联网，使在工业设置中部署上千个传感器。
|
||||
|
||||
即使仍在胚胎当中，6G 已经由于新发现的 [tera-hretz 中基于网络的潜在的中间人攻击][29]的紧迫性面临安全的考虑。好消息是有大量时间来解决这个问题。6G 网络直到 2030 之前才可能出现。
|
||||
|
||||
**阅读更多关于 5G 网络：**
|
||||
|
||||
* [How enterprises can prep for 5G networks][30]
|
||||
* [5G vs 4G: How speed, latency and apps support differ][31]
|
||||
* [Private 5G networks are coming][32]
|
||||
* [5G and 6G wireless have security issues][33]
|
||||
* [How millimeter-wave wireless could help support 5G and IoT][34]
|
||||
|
||||
|
||||
在 [Facebook][35] 和 [LinkedIn][36] 上加入网络世界社区来评论当前最热门的话题。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3203489/what-is-5g-how-is-it-better-than-4g.html#tk.rss_all
|
||||
|
||||
作者：[Josh Fruhlinger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Josh-Fruhlinger/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://images.techhive.com/images/article/2017/04/5g-100718139-large.jpg
|
||||
[2]: https://www.networkworld.com/article/3203489/what-is-5g-wireless-networking-benefits-standards-availability-versus-lte.html
|
||||
[3]: https://www.networkworld.com/article/3354477/mobile-world-congress-the-time-of-5g-is-almost-here.html
|
||||
[4]: https://www.networkworld.com/article/3330603/5g-versus-4g-how-speed-latency-and-application-support-differ.html
|
||||
[5]: https://www.theverge.com/2018/6/15/17467734/5g-nr-standard-3gpp-standalone-finished
|
||||
[6]: https://pluralsight.pxf.io/c/321564/424552/7490?u=https%3A%2F%2Fwww.pluralsight.com%2Fcourses%2Fmobile-device-management-big-picture
|
||||
[7]: https://www.networkworld.com/article/3291323/millimeter-wave-wireless-could-help-support-5g-and-iot.html
|
||||
[8]: https://spectrum.ieee.org/video/telecom/wireless/5g-bytes-small-cells-explained
|
||||
[9]: https://www.networkworld.com/article/3250268/what-is-mu-mimo-and-why-you-need-it-in-your-wireless-routers.html
|
||||
[10]: https://spectrum.ieee.org/tech-talk/telecom/wireless/5g-researchers-achieve-new-spectrum-efficiency-record
|
||||
[11]: https://www.networkworld.com/article/3262991/future-wireless-networks-will-have-no-capacity-limits.html
|
||||
[12]: https://venturebeat.com/2018/05/14/worlds-first-commercial-5g-network-launches-in-qatar/
|
||||
[13]: https://www.lifewire.com/5g-availability-world-4156244
|
||||
[14]: https://www.digitaltrends.com/computing/verizon-5g-home-promises-up-to-gigabit-internet-speeds-for-50/
|
||||
[15]: https://lifehacker.com/heres-your-cheat-sheet-for-verizons-new-5g-data-plans-1833278817
|
||||
[16]: https://www.theverge.com/2018/10/2/17927712/verizon-5g-home-internet-real-speed-meaning
|
||||
[17]: https://www.cnn.com/2018/12/18/tech/5g-mobile-att/index.html
|
||||
[18]: https://www.networkworld.com/article/3339720/like-4g-before-it-5g-is-being-hyped.html?nsdr=true
|
||||
[19]: https://www.digitaltrends.com/mobile/sprint-5g-rollout/
|
||||
[20]: https://www.cnet.com/news/t-mobile-delays-full-600-mhz-5g-launch-until-second-half/
|
||||
[21]: https://lets5g.com/
|
||||
[22]: https://www.verizonwireless.com/support/5g-moto-mod-faqs/?AID=11365093&SID=100098X1555750Xbc2e857934b22ebca1a0570d5ba93b7c&vendorid=CJM&PUBID=7105813&cjevent=2e2150cb478c11e98183013b0a1c0e0c
|
||||
[23]: https://www.digitaltrends.com/cell-phone-reviews/moto-z3-review/
|
||||
[24]: https://www.businessinsider.com/samsung-galaxy-s10-5g-which-us-cities-have-5g-networks-2019-2
|
||||
[25]: https://www.cnet.com/news/why-apples-in-no-rush-to-sell-you-a-5g-iphone/
|
||||
[26]: https://mashable.com/2012/09/09/iphone-5-4g-lte/#hYyQUelYo8qq
|
||||
[27]: https://www.networkworld.com/article/3305359/6g-will-achieve-terabits-per-second-speeds.html
|
||||
[28]: https://www.networkworld.com/article/3285112/get-ready-for-upcoming-6g-wireless-too.html
|
||||
[29]: https://www.networkworld.com/article/3315626/5g-and-6g-wireless-technologies-have-security-issues.html
|
||||
[30]: https://%20https//www.networkworld.com/article/3306720/mobile-wireless/how-enterprises-can-prep-for-5g.html
|
||||
[31]: https://%20https//www.networkworld.com/article/3330603/mobile-wireless/5g-versus-4g-how-speed-latency-and-application-support-differ.html
|
||||
[32]: https://%20https//www.networkworld.com/article/3319176/mobile-wireless/private-5g-networks-are-coming.html
|
||||
[33]: https://www.networkworld.com/article/3315626/network-security/5g-and-6g-wireless-technologies-have-security-issues.html
|
||||
[34]: https://www.networkworld.com/article/3291323/mobile-wireless/millimeter-wave-wireless-could-help-support-5g-and-iot.html
|
||||
[35]: https://www.facebook.com/NetworkWorld/
|
||||
[36]: https://www.linkedin.com/company/network-world
|
||||
|
||||
@ -0,0 +1,89 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (MjSeven)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Command line quick tips: Cutting content out of files)
|
||||
[#]: via: (https://fedoramagazine.org/command-line-quick-tips-cutting-content-out-of-files/)
|
||||
[#]: author: (Stephen Snow https://fedoramagazine.org/author/jakfrost/)
|
||||
|
||||
命令行技巧：分割文件内容
|
||||
======
|
||||
|
||||
![][1]
|
||||
|
||||
Fedora 发行版是一个功能齐全的操作系统，有出色的图形化桌面环境。用户可以很容易地通过单击动作来完成任何典型任务。所有这些美妙的易用性掩盖了其底层强大的命令行细节。本文是向你展示一些常见命令行实用程序的系列文章的一部分。让我们进入 shell 来看看 **cut**。
|
||||
|
||||
通常，当你在命令行中工作时，你处理的是文本文件。有时这些文件可能很长，虽然可以完整地阅读它们，但是可能会耗费大量时间，并且容易出错。在本文中，你将学习如何从文本文件中提取内容，并从中获取你所需的信息。
|
||||
|
||||
重要的是要意识到，在 Fedora 中有许多方法可以完成类似的命令行任务。例如，Fedora 仓库含有用于解析和处理文本的完整语言系统。此外，还有多个命令行实用程序可用于 shell 中任何可能的用途。本文只关注使用其中几个实用程序选项，从文件中提取一些信息并以可读的格式呈现。
|
||||
|
||||
### cut 使用
|
||||
|
||||
为了演示这个例子，在系统上使用一个标准的大文件，如 _/etc/passwd_。正如本系列的前一篇文章所示，你可以执行 _cat_ 命令来查看整个文件：
|
||||
```
|
||||
$ cat /etc/passwd
|
||||
root:x:0:0:root:/root:/bin/bash
|
||||
bin:x:1:1:bin:/bin:/sbin/nologin
|
||||
daemon:x:2:2:daemon:/sbin:/sbin/nologin
|
||||
adm:x:3:4:adm:/var/adm:/sbin/nologin
|
||||
...
|
||||
```
|
||||
|
||||
此文件包含系统上所有所有账户的信息。它有一个特定的格式：
|
||||
|
||||
```
|
||||
name:password:user-id:group-id:comment:home-directory:shell
|
||||
```
|
||||
假设你只想要系统上所有账户名的列表，如果你只能从每一行中删除 _name_ 值。这就是 _cut_ 命令派上用场的地方！它一次处理一行输入，并提取该行的特定部分。
|
||||
|
||||
_cut_ 命令提供了以不同方式选择一行的部分的选项，在本示例中需要两个，_d_ 是指定要使用的分隔符类型，_f_ 是指定要删除行的哪个字段。_-d_ 选项允许你声明用于分隔行中值的 _delimiter_。在本例中，冒号(:)用于分隔值。_-f_ 选项允许你选择要提取哪个字段或哪些字段值。因此，在本例中，输入的命令是：
|
||||
|
||||
```
|
||||
$ cut -d: -f1 /etc/passwd
|
||||
root
|
||||
bin
|
||||
daemon
|
||||
adm
|
||||
...
|
||||
```
|
||||
|
||||
太棒了，成功了！但是你将输出打印到标准输出，在终端会话中意味着它需要占据屏幕。如果你需要稍后完成另一项任务所需的信息，这该怎么办？如果有办法将 _cut_ 命令的输出保存到文本文件中，那就太好了。对于这样的任务，shell 有一个简单的内置功能，重定向功能(_>_)。
|
||||
|
||||
```
|
||||
$ cut -d: -f1 /etc/passwd > names.txt
|
||||
```
|
||||
|
||||
这会将 cut 的输出放到一个名为 _names.txt_ 的文件中，你可以使用 _cat_ 来查看它的内容:
|
||||
|
||||
```
|
||||
$ cat names.txt
|
||||
root
|
||||
bin
|
||||
daemon
|
||||
adm
|
||||
...
|
||||
```
|
||||
|
||||
使用两个命令和一个 shell 功能，可以很容易地使用 _cat_ 从一个文件进行识别、提取和重定向一些信息，并将其保存到另一个文件以供以后使用。
|
||||
|
||||
* * *
|
||||
|
||||
_[ _Joel Mbugua_][2]_ 在 _[_Unsplash_][3] 上的照片._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/command-line-quick-tips-cutting-content-out-of-files/
|
||||
|
||||
作者：[Stephen Snow][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[MjSeven](https://github.com/MjSeven)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://fedoramagazine.org/author/jakfrost/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://fedoramagazine.org/wp-content/uploads/2019/04/commandline-cutting-816x345.jpg
|
||||
[2]: https://unsplash.com/photos/tA5eSY_hay8?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
[3]: https://unsplash.com/search/photos/command-line?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText
|
||||
@ -0,0 +1,262 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How To Install And Configure NTP Server And NTP Client In Linux?)
|
||||
[#]: via: (https://www.2daygeek.com/install-configure-ntp-server-ntp-client-in-linux/)
|
||||
[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/)
|
||||
|
||||
如何在Linux上安装、配置NTP服务和NTP客户端？
|
||||
======
|
||||
|
||||
你也许听说过这个词很多次或者你可能已经在使用它了。
|
||||
但是，在这篇文章中我将会清晰的告诉你NTP服务和NTP客户端的安装。
|
||||
|
||||
之后我们将会了解 **[Chrony NTP 客户端的安装][1]**。
|
||||
|
||||
|
||||
### 什么是NTP服务?
|
||||
|
||||
NTP 表示为网络时间协议。
|
||||
|
||||
它是通过网络在电脑系统之间进行时钟同步的网络协议。
|
||||
|
||||
另一方面，我可以说，它可以让那些通过NTP或者Chrony客户端连接到NTP服务的系统保持时间上的一致（它能保持一个精确的时间）。
|
||||
|
||||
|
||||
NTP在公共互联网上通常能够保持时间延迟在几十毫秒以内的精度，并在理想条件下，它能在局域网下达到优于一毫秒的延迟精度。
|
||||
|
||||
它使用用户数据报协议（UDP）在端口123上发送和接受时间戳。它是C/S架构的应用程序。
|
||||
|
||||
|
||||
|
||||
### 什么是NTP客户端？
|
||||
|
||||
NTP客户端将其时钟与网络时间服务器同步。
|
||||
|
||||
### 什么是Chrony客户端？
|
||||
Chrony是NTP客户端的替代品。它能以更精确的时间更快的同步系统时钟，并且它对于那些不总是在线的系统很有用。
|
||||
|
||||
### 为什么我们需要NTP服务？
|
||||
|
||||
为了使你组织中的所有服务器与基于时间的作业保持精确的时间同步。
|
||||
|
||||
为了说明这点，我将告诉你一个场景。比如说，我们有两个服务器（服务器1和服务器2）。服务器1通常在10:55完成离线作业，然后服务器2在11:00需要基于服务器1完成的作业报告去运行其他作业。
|
||||
|
||||
如果两个服务器正在使用不同的时间（如果服务器2时间比服务器1提前，服务器1的时间就落后于服务器2），然后我们就不能去执行这个作业。为了达到时间一致，我们应该安装NTP。
|
||||
希望上述能清除你对于NTP的疑惑。
|
||||
|
||||
|
||||
在这篇文章中，我们将使用下列设置去测试。
|
||||
|
||||
* **`NTP Server:`** HostName: CentOS7.2daygeek.com, IP:192.168.1.8, OS:CentOS 7
|
||||
* **`NTP Client:`** HostName: Ubuntu18.2daygeek.com, IP:192.168.1.5, OS:Ubuntu 18.04
|
||||
|
||||
|
||||
|
||||
### NTP服务端： 如何在Linux上安装NTP？
|
||||
|
||||
因为它是c/s架构，所以NTP服务端和客户端的安装包没有什么不同。在发行版的官方仓库中都有NTP安装包，因此可以使用发行版的包管理器安装它。
|
||||
|
||||
对于 **`Fedora`** 系统, 使用 **[DNF 命令][2]** 去安装ntp.
|
||||
|
||||
```
|
||||
$ sudo dnf install ntp
|
||||
```
|
||||
|
||||
对于 **`Debian/Ubuntu`** 系统, 使用 **[APT-GET 命令][3]** 或者 **[APT 命令][4]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$
|
||||
```
|
||||
|
||||
对基于 **`Arch Linux`** 的系统, 使用 **[Pacman 命令][5]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo pacman -S ntp
|
||||
```
|
||||
|
||||
对 **`RHEL/CentOS`** 系统, 使用 **[YUM 命令][6]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo yum install ntp
|
||||
```
|
||||
|
||||
对于 **`openSUSE Leap`** 系统, 使用 **[Zypper 命令][7]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo zypper install ntp
|
||||
```
|
||||
|
||||
### 如何在Linux上配置NTP服务？
|
||||
|
||||
安装NTP软件包后，请确保在服务器端的`/etc/ntp.conf`文件中，必须取消以下配置的注释。
|
||||
|
||||
默认情况下，NTP服务器配置依赖于`X.distribution_name.pool.ntp.org`。 如果有必要，可以使用默认配置，也可以访问<https://www.ntppool.org/zone/@>站点，根据你所在的位置（特定国家/地区）进行更改。
|
||||
|
||||
比如说如果你在印度，然后你的NTP服务器将是`0.in.pool.ntp.org`，并且这个地址适用于大多数国家。
|
||||
|
||||
```
|
||||
# vi /etc/ntp.conf
|
||||
|
||||
restrict default kod nomodify notrap nopeer noquery
|
||||
restrict -6 default kod nomodify notrap nopeer noquery
|
||||
restrict 127.0.0.1
|
||||
restrict -6 ::1
|
||||
server 0.asia.pool.ntp.org
|
||||
server 1.asia.pool.ntp.org
|
||||
server 2.asia.pool.ntp.org
|
||||
server 3.asia.pool.ntp.org
|
||||
restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
|
||||
driftfile /var/lib/ntp/drift
|
||||
keys /etc/ntp/keys
|
||||
```
|
||||
|
||||
我们仅允许`192.168.1.0/24`子网的客户端访问NTP服务器。
|
||||
|
||||
由于默认情况下基于RHEL7的发行版的防火墙是打开的，因此允许ntp服务通过。
|
||||
|
||||
```
|
||||
# firewall-cmd --add-service=ntp --permanent
|
||||
# firewall-cmd --reload
|
||||
```
|
||||
|
||||
更新配置后重启服务。
|
||||
|
||||
对于基于Debian的sysvinit系统，我们需要去运行`ntp`而不是`ntpd`。
|
||||
|
||||
```
|
||||
# service ntpd restart
|
||||
|
||||
# chkconfig ntpd on
|
||||
```
|
||||
对于基于Debian的systemctl系统，我们需要去运行`ntp`和`ntpd`。
|
||||
|
||||
```
|
||||
# systemctl restart ntpd
|
||||
|
||||
# systemctl enable ntpd
|
||||
```
|
||||
|
||||
### NTP客户端：如何在Linux上安装NTP客户端？
|
||||
|
||||
正如我在这篇文章中前面所说的。NTP服务端和客户端的安装包没有什么不同。因此在客户端上也安装同样的软件包。
|
||||
|
||||
对于 **`Fedora`** 系统, 使用 **[DNF 命令][2]** 去安装ntp.
|
||||
|
||||
```
|
||||
$ sudo dnf install ntp
|
||||
```
|
||||
|
||||
对于 **`Debian/Ubuntu`** 系统, 使用 **[APT-GET 命令][3]** 或者 **[APT 命令][4]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$
|
||||
```
|
||||
|
||||
对基于 **`Arch Linux`** 的系统, 使用 **[Pacman 命令][5]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo pacman -S ntp
|
||||
```
|
||||
|
||||
对 **`RHEL/CentOS`** 系统, 使用 **[YUM 命令][6]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo yum install ntp
|
||||
```
|
||||
|
||||
对于 **`openSUSE Leap`** 系统, 使用 **[Zypper 命令][7]** 去安装 ntp.
|
||||
|
||||
```
|
||||
$ sudo zypper install ntp
|
||||
```
|
||||
|
||||
我已经在`CentOS7.2daygeek.com`这台主机上安装和配置了NTP服务器，因此将其附加到所有的客户端机器上。
|
||||
|
||||
```
|
||||
# vi /etc/ntp.conf
|
||||
|
||||
restrict default kod nomodify notrap nopeer noquery
|
||||
restrict -6 default kod nomodify notrap nopeer noquery
|
||||
restrict 127.0.0.1
|
||||
restrict -6 ::1
|
||||
server CentOS7.2daygeek.com prefer iburst
|
||||
driftfile /var/lib/ntp/drift
|
||||
keys /etc/ntp/keys
|
||||
```
|
||||
|
||||
更新配置后重启服务。
|
||||
|
||||
对于基于Debian的sysvinit系统，我们需要去运行`ntp`而不是`ntpd`。
|
||||
|
||||
```
|
||||
# service ntpd restart
|
||||
|
||||
# chkconfig ntpd on
|
||||
```
|
||||
对于基于Debian的systemctl系统，我们需要去运行`ntp`和`ntpd`。
|
||||
|
||||
```
|
||||
# systemctl restart ntpd
|
||||
|
||||
# systemctl enable ntpd
|
||||
```
|
||||
|
||||
重新启动NTP服务后等待几分钟以便从NTP服务器获取同步的时间。
|
||||
|
||||
在Linux上运行下列命令去验证NTP服务的同步状态。
|
||||
|
||||
```
|
||||
# ntpq –p
|
||||
或
|
||||
# ntpq -pn
|
||||
|
||||
remote refid st t when poll reach delay offset jitter
|
||||
==============================================================================
|
||||
*CentOS7.2daygee 133.243.238.163 2 u 14 64 37 0.686 0.151 16.432
|
||||
```
|
||||
|
||||
运行下列命令去得到ntpd的当前状态。
|
||||
|
||||
```
|
||||
# ntpstat
|
||||
synchronised to NTP server (192.168.1.8) at stratum 3
|
||||
time correct to within 508 ms
|
||||
polling server every 64 s
|
||||
```
|
||||
|
||||
最后运行`date`命令。
|
||||
|
||||
```
|
||||
# date
|
||||
Tue Mar 26 23:17:05 CDT 2019
|
||||
```
|
||||
|
||||
如果你观察到NTP中输出的偏移很大。运行下列命令从NTP服务器手动同步时钟。当你执行下列命令的时候，确保你的NTP客户端应该为未激活状态。
|
||||
|
||||
```
|
||||
# ntpdate –uv CentOS7.2daygeek.com
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.2daygeek.com/install-configure-ntp-server-ntp-client-in-linux/
|
||||
|
||||
作者：[Magesh Maruthamuthu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[arrowfeng](https://github.com/arrowfeng)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.2daygeek.com/author/magesh/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.2daygeek.com/configure-ntp-client-using-chrony-in-linux/
|
||||
[2]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/
|
||||
[3]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[4]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/
|
||||
[5]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/
|
||||
[6]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/
|
||||
[7]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/
|
||||
@ -0,0 +1,138 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Installing Ubuntu MATE on a Raspberry Pi)
|
||||
[#]: via: (https://itsfoss.com/ubuntu-mate-raspberry-pi/)
|
||||
[#]: author: (Chinmay https://itsfoss.com/author/chinmay/)
|
||||
|
||||
在 Raspberry Pi 上安装 Ubuntu MATE
|
||||
=================================
|
||||
|
||||
_**简介: 这篇快速指南告诉你如何在 Raspberry Pi 设备上安装 Ubuntu MATE。**_
|
||||
|
||||
[Raspberry Pi][1] 是目前最流行的单板机并且是制造商的首选。[Raspbian][2] 是基于 Debian 的 Pi 的官方操作系统。它是轻量级的，内置了教育工具和能在大部分场景下完成工作的工具。
|
||||
|
||||
[安装 Raspbian][3] 安装同样简单，但是与 [Debian][4] 一起的问题是慢的升级周期和旧的软件包。
|
||||
|
||||
在 Raspberry Pi 上运行 Ubuntu 给你带来一个更丰富的体验和最新的软件。当在你的 Pi 上运行 Ubuntu 时我们有几个选择。
|
||||
|
||||
1. [Ubuntu MATE][5] ：Ubuntu MATE 是仅有的原生支持 Raspberry Pi 包含一个完整的桌面环境的分发版。
|
||||
2. [Ubuntu Server 18.04][6] \+ 手动安装一个桌面环境。
|
||||
3. 使用 [Ubuntu Pi Flavor Maker][7] 社区构建的镜像，_这些镜像只支持 Raspberry Pi 2B 和 3B 的变种_并且**不能**更新到最新的 LTS 发布版。
|
||||
|
||||
|
||||
|
||||
|
||||
第一个选择安装是最简单和快速的，而第二个选择给了你自由选择安装桌面环境的机会。我推荐选择前两个中的任一个。
|
||||
|
||||
这里是一些磁盘镜像下载链接。在这篇文章里我只会提及 Ubuntu MATE 的安装。
|
||||
|
||||
### 在 Raspberry Pi 上安装 Ubuntu MATE
|
||||
|
||||
去 Ubuntu MATE 的下载页面获取推荐的镜像。
|
||||
|
||||
![][8]
|
||||
|
||||
试验 ARM64 版只应在你需要在 Raspberry Pi 服务器上运行像 MongoDB 这样的 64-bit 应用时使用。
|
||||
|
||||
[ 下载为 Raspberry Pi 准备的 Ubuntu MATE][9]
|
||||
|
||||
#### 第 1 步：设置 SD 卡
|
||||
|
||||
镜像文件一旦下载完成后需要解压。你应该简单的右击来提取它。
|
||||
|
||||
可替换地，下面命令做同样的事。
|
||||
|
||||
```
|
||||
xz -d ubuntu-mate***.img.xz
|
||||
```
|
||||
|
||||
如果你在 Windows 上你可以使用 [7-zip][10] 替代。
|
||||
|
||||
安装 **[Balena Etcher][11]**，我们将使用这个工具将镜像写入 SD 卡。确保你的 SD 卡有至少 8 GB 的容量。
|
||||
|
||||
启动 Etcher，选择镜像文件和 SD 卡。
|
||||
|
||||
![][12]
|
||||
|
||||
一旦进度完成 SD 卡就准备好了。
|
||||
|
||||
#### 第 2 步：设置 Raspberry Pi
|
||||
|
||||
你可能已经知道你需要一些外设才能使用 Raspberry Pi 例如 鼠标，键盘， HDMI 线等等。你同样可以[不用键盘和鼠标安装 Raspberry Pi][13] 但是这篇指南不是那样。
|
||||
|
||||
* 插入一个鼠标和一个键盘。
|
||||
* 连接 HDMI 线缆。
|
||||
* 插入 SD 卡 到 SD 卡槽。
|
||||
|
||||
|
||||
|
||||
插入电源线给它供电。确保你有一个好的电源供应（5V，3A 至少）。一个不好的电源供应可能降低性能。
|
||||
|
||||
#### Ubuntu MATE 安装
|
||||
|
||||
一旦你给 Raspberry Pi 供电，你将遇到非常熟悉的 Ubuntu 安装过程。在这里的安装过程相当直接。
|
||||
|
||||
![选择你的键盘布局][14]
|
||||
|
||||
![选择你的时区][15]
|
||||
|
||||
选择你的 WiFi 网络并且在网络连接中输入密码。
|
||||
|
||||
![添加用户名和密码][16]
|
||||
|
||||
在设置了键盘布局，时区和用户凭证后，在几分钟后你将被带到登录界面。瞧！你快要完成了。
|
||||
|
||||
![][17]
|
||||
|
||||
一旦登录，第一件事你应该做的是[更新 Ubuntu][18]。你应该使用下列命令。
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
sudo apt upgrade
|
||||
```
|
||||
|
||||
你同样可以使用软件更新器。
|
||||
|
||||
![][19]
|
||||
|
||||
一旦更新完成安装你就可以开始了。你可以根据你的需要继续安装 Raspberry Pi 平台的为 GPIO 和其他 I/O 准备的特定软件包。
|
||||
|
||||
是什么让你考虑在 Raspberry 上安装 Ubuntu，你对 Raspbian 的体验如何呢？在下方评论来让我知道。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/ubuntu-mate-raspberry-pi/
|
||||
|
||||
作者：[Chinmay][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/chinmay/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.raspberrypi.org/
|
||||
[2]: https://www.raspberrypi.org/downloads/
|
||||
[3]: https://itsfoss.com/tutorial-how-to-install-raspberry-pi-os-raspbian-wheezy/
|
||||
[4]: https://www.debian.org/
|
||||
[5]: https://ubuntu-mate.org/
|
||||
[6]: https://wiki.ubuntu.com/ARM/RaspberryPi#Recovering_a_system_using_the_generic_kernel
|
||||
[7]: https://ubuntu-pi-flavour-maker.org/download/
|
||||
[8]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/ubuntu-mate-raspberry-pi-download.jpg?ssl=1
|
||||
[9]: https://ubuntu-mate.org/download/
|
||||
[10]: https://www.7-zip.org/download.html
|
||||
[11]: https://www.balena.io/etcher/
|
||||
[12]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/Screenshot-from-2019-04-08-01-36-16.png?ssl=1
|
||||
[13]: https://linuxhandbook.com/raspberry-pi-headless-setup/
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Keyboard-layout-ubuntu.jpg?fit=800%2C467&ssl=1
|
||||
[15]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/select-time-zone-ubuntu.jpg?fit=800%2C468&ssl=1
|
||||
[16]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Credentials-ubuntu.jpg?fit=800%2C469&ssl=1
|
||||
[17]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Desktop-ubuntu.jpg?fit=800%2C600&ssl=1
|
||||
[18]: https://itsfoss.com/update-ubuntu/
|
||||
[19]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/update-software.png?ssl=1
|
||||
|
||||
|
||||
@ -0,0 +1,351 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (12 Single Board Computers: Alternative to Raspberry Pi)
|
||||
[#]: via: (https://itsfoss.com/raspberry-pi-alternatives/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
12 个可替换 Raspberry Pi 的单片机
|
||||
================================
|
||||
|
||||
_**简介： 正在寻找 Raspberry Pi 的替代品？ 这里有一些单片机可以满足你的 DIY 渴求**_
|
||||
|
||||
Raspberry Pi 是当前最流行的单片机。你可以在你的 DIY 项目中使用它，或者用它作为一个成本效益高的系统来学习编代码，或者为了你的便利，利用一个[流媒体软件][1]运行在上面作为流媒体设备。
|
||||
|
||||
你可以使用 Raspberry Pi 做很多事，但它不是各种极客的最终解决方案。一些人可能在寻找更便宜的开发板，一些可能在寻找更强大的。
|
||||
|
||||
无论是哪种情况，我们都有很多原因需要 Raspberry Pi 的替代品。因此，在这片文章里，我们将讨论最好的十个我们认为能够替代 Raspberry Pi 的单片机。
|
||||
|
||||
![][2]
|
||||
|
||||
### 满足你 DIY 渴望的 Raspberry Pi 替代品
|
||||
|
||||
这个列表没有特定的顺序排名。链接的一部分是附属链接。请阅读我们的[附属政策][3].
|
||||
|
||||
#### 1\. Onion Omega2+
|
||||
|
||||
![][4]
|
||||
|
||||
只要 **$13**，Omega2+ 是这里你可以找到的最便宜的 IoT 单片机设备。它运行 LEDE（Linux 嵌入式开发环境）Linux 系统 - 一个基于 [OpenWRT][5] 的分发版。
|
||||
|
||||
由于运行一个自定义 Linux 系统，它的组成因素，花费，和灵活性使它完美适合几乎所有类型的 IoT 应用。
|
||||
|
||||
你可以在[亚马逊商城的 Onion Omega 装备][6]或者从他们的网站下单，可能会收取额外的邮费。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* MT7688 SoC
|
||||
* 2.4 GHz IEEE 802.11 b/g/n WiFi
|
||||
* 128 MB DDR2 RAM
|
||||
* 32 MB on-board flash storage
|
||||
* MicroSD Slot
|
||||
* USB 2.0
|
||||
* 12 GPIO Pins
|
||||
|
||||
[查看官网][7]
|
||||
|
||||
#### 2\. NVIDIA Jetson Nano Developer Kit
|
||||
|
||||
这是来自 NVIDIA 的只要 **$99** 的非常独特和有趣的 Raspberry Pi 替代品。是的，它不是每个人都能充分利用的设备 - 只为特定的一组极客或者开发者。
|
||||
|
||||
NVIDIA 使用下面的用例解释它：
|
||||
|
||||
> NVIDIA® Jetson Nano™ Developer Kit 是一个小的，强大的让你并行运行多个神经网络的应用像图像分类，对象侦察，分段，语音处理。全部在一个易于使用的运行功率只有 5 瓦特平台。
|
||||
>
|
||||
> nvidia
|
||||
|
||||
因此，基本上，如果你正在研究 AI 或者深度学习，你可以充分利用开发设备。如果你很好奇，该设备的产品计算模块将在 2019 年 7 月到来。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* CPU: Quad-core ARM A57 @ 1.43 GHz
|
||||
* GPU: 128-core Maxwell
|
||||
* RAM: 4 GB 64-bit LPDDR4 25.6 GB/s
|
||||
* Display: HDMI 2.0
|
||||
* 4 x USB 3.0 and eDP 1.4
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][9]
|
||||
|
||||
#### 3\. ASUS Tinker Board S
|
||||
|
||||
![][10]
|
||||
|
||||
ASUS Tinker Board S 不是大多数可负担得起的可替代 Raspberry Pi 的替换设备 （**$82**, [亚马逊商城][11])，但是它是一个强大的替代品。它的特点是有你通常可以发现与标准 Raspberry Pi 3 Model 一样的 40 针脚的连接器，但是提供了强大的处理器和 GPU。同样的，Tinker Board S 的大小恰巧和标准的 Raspberry Pi 3 一样大。
|
||||
|
||||
这个板子的主要亮点是 16 GB [eMMC][12] （用外行术语说，它的板上有一个类似 SSD 的存储单元使它工作时运行的更快。） 的存在。
|
||||
|
||||
**关键参数**
|
||||
|
||||
* Rockchip Quad-Core RK3288 processor
|
||||
* 2 GB DDR3 RAM
|
||||
* Integrated Graphics Processor
|
||||
* ARM® Mali™-T764 GPU
|
||||
* 16 GB eMMC
|
||||
* MicroSD Card Slot
|
||||
* 802.11 b/g/n, Bluetooth V4.0 + EDR
|
||||
* USB 2.0
|
||||
* 28 GPIO pins
|
||||
* HDMI Interface
|
||||
|
||||
|
||||
|
||||
[查看网站
|
||||
][13]
|
||||
|
||||
#### 4\. ClockworkPi
|
||||
|
||||
![][14]
|
||||
|
||||
如果你在想方设法组装一个模块化的复古的游戏控制台，Clockwork Pi 通常是 [GameShell Kit][15] 的一部分。然而，你可以 使用 $49 单独购买板子。
|
||||
|
||||
它紧凑的大小，WiFi 连接性，和 micro HDMI 端口的存在使它成为很多事物的选择。
|
||||
|
||||
**关键参数**
|
||||
|
||||
* Allwinner R16-J Quad-core Cortex-A7 CPU @1.2GHz
|
||||
* Mali-400 MP2 GPU
|
||||
* RAM: 1GB DDR3
|
||||
* WiFi & Bluetooth v4.0
|
||||
* Micro HDMI output
|
||||
* MicroSD Card Slot
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][16]
|
||||
|
||||
#### 5\. Arduino Mega 2560
|
||||
|
||||
![][17]
|
||||
|
||||
如果你正在研究机器人项目或者你想要一个 3D 打印机 - Arduino Mega 2560 将是 Raspberry Pi 的便利的替代品。不像 Raspberry Pi，它是基于微控制器而不是微处理器的。
|
||||
|
||||
在他们的[官网][18]，它会花费你 $38.50 或者在[在亚马逊商城 $33][19]。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
**Key Specifications:**
|
||||
|
||||
* Microcontroller: ATmega2560
|
||||
* Clock Speed: 16 MHz
|
||||
* Digital I/O Pins: 54
|
||||
* Analog Input Pins: 16
|
||||
* Flash Memory: 256 KB of which 8 KB used by bootloader
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][18]
|
||||
|
||||
#### 6\. Rock64 Media Board
|
||||
|
||||
![][20]
|
||||
|
||||
对于与你可能想要 Raspberry Pi 3 B+ 相同的投资，你将在 Rock64 Media Board 上获得更快的处理器和双倍的内存。除此之外，如果你想要 1 GB RAM 版的，它提供了一个 Raspberry Pi 的 更便宜的替代，花费更少，只要 $10 。
|
||||
|
||||
不像 Raspberry Pi，这里没有无线连接支持，但是 USB 3.0 和 HDMI 2.0 的存在使它与众不同，如果它对你很重要的话。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* Rockchip RK3328 Quad-Core ARM Cortex A53 64-Bit Processor
|
||||
* Supports up to 4GB 1600MHz LPDDR3 RAM
|
||||
* eMMC module socket
|
||||
* MicroSD Card slot
|
||||
* USB 3.0
|
||||
* HDMI 2.0
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][21]
|
||||
|
||||
#### 7\. Odroid-XU4
|
||||
|
||||
![][22]
|
||||
|
||||
Odroid-XU4 是一个完美的 Raspberry Pi 的替代,如果你有能够稍微提高预算的空间（$80-$100 甚至更低，取决于存储的容量）。
|
||||
|
||||
它确实是一个强大的替代并且体积更小。 支持 eMMC 和 USB 3.0 使它工作起来更快。
|
||||
|
||||
**关键参数：**
|
||||
* Samsung Exynos 5422 Octa ARM Cortex™-A15 Quad 2Ghz and Cortex™-A7 Quad 1.3GHz CPUs
|
||||
* 2Gbyte LPDDR3 RAM
|
||||
* GPU: Mali-T628 MP6
|
||||
* USB 3.0
|
||||
* HDMI 1.4a
|
||||
* eMMC 5.0 module socket
|
||||
* MicroSD Card Slot
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][23]
|
||||
|
||||
#### 8\. **PocketBeagle**
|
||||
|
||||
![][24]
|
||||
|
||||
它是一个难以置信的小的单片机 - 几乎和 Raspberry Pi Zero 相似。然而它会花费完全大小的 Raspberry Pi 3 相同的价格。主要的亮点是你可以用它作为一个 USB 便携式信息终端 并且进入 Linux 命令行工作。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* Processor: Octavo Systems OSD3358 1GHz ARM® Cortex-A8
|
||||
* RAM: 512 MB DDR3
|
||||
* 72 expansion pin headers
|
||||
* microUSB
|
||||
* USB 2.0
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][25]
|
||||
|
||||
#### 9\. Le Potato
|
||||
|
||||
![][26]
|
||||
|
||||
由 [Libre Computer][27] 出品的 Le Potato，同样被它的型号 AML-S905X-CC 标识。它花费你 [$45][28]。
|
||||
|
||||
如果你花费的比 Raspberry Pi 更多的钱，你就能得到想要双倍内存和 HDMI 2.0 接口，这可能是一个完美的选择。尽管，你还是不能发现嵌入的无线连接。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
|
||||
* Amlogic S905X SoC
|
||||
* 2GB DDR3 SDRAM
|
||||
* USB 2.0
|
||||
* HDMI 2.0
|
||||
* microUSB
|
||||
* MicroSD Card Slot
|
||||
* eMMC Interface
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][29]
|
||||
|
||||
#### 10\. Banana Pi M64
|
||||
|
||||
![][30]
|
||||
|
||||
它自带了 8 Gigs 的 eMMC - 是替代 Raspberry Pi 的主要亮点。由于相同的原因，它花费 $60。
|
||||
|
||||
HDMI 接口的存在使它胜任 4K。除此之外，Banana Pi 提供了更多种类的开源单片机作为 Raspberry Pi 的替代。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* 1.2 Ghz Quad-Core ARM Cortex A53 64-Bit Processor-R18
|
||||
* 2GB DDR3 SDRAM
|
||||
* 8 GB eMMC
|
||||
* WiFi & Bluetooth
|
||||
* USB 2.0
|
||||
* HDMI
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][31]
|
||||
|
||||
#### 11\. Orange Pi Zero
|
||||
|
||||
![][32]
|
||||
|
||||
Orange Pi Zero 相对于 Raspberry Pi 难以置信的便宜。你可以在 Aliexpress 或者亚马逊上以最多 $10 就能够获得。如果[稍微投资多点，你能够获得 512 MB RAM][33]。
|
||||
|
||||
如果这还不够充分，你可以花费大概 $25 获得更好的配置像 Orange Pi 3。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* H2 Quad-core Cortex-A7
|
||||
* Mali400MP2 GPU
|
||||
* RAM: Up to 512 MB
|
||||
* TF Card support
|
||||
* WiFi
|
||||
* USB 2.0
|
||||
|
||||
|
||||
|
||||
[查看官网
|
||||
][34]
|
||||
|
||||
#### 12\. VIM 2 SBC by Khadas
|
||||
|
||||
![][35]
|
||||
|
||||
由 Khadas 出品的 VIM 2 是最新的单片机，因此你能够在板上获取到蓝牙 5.0。[从 $99 的基础款到上限 $140][36].
|
||||
|
||||
基础款包含 2 GB RAM，16 GB eMMC 和蓝牙 4.1。然而，Pro/Max 版包含蓝牙 5.0，更多的内存，更多的 eMMC 存储。
|
||||
|
||||
**关键参数：**
|
||||
|
||||
* Amlogic S912 1.5GHz 64-bit Octa-Core CPU
|
||||
* T820MP3 GPU
|
||||
* Up to 3 GB DDR4 RAM
|
||||
* Up to 64 GB eMMC
|
||||
* Bluetooth 5.0 (Pro/Max)
|
||||
* Bluetooth 4.1 (Basic)
|
||||
* HDMI 2.0a
|
||||
* WiFi
|
||||
|
||||
|
||||
|
||||
**总结**
|
||||
|
||||
我们知道有很多不同种类的单片机电脑。一些比 Raspberry Pi 更好 - 它的一些小规格的版本有更便宜的价格。同样的，单片机像 Jetson Nano 已经被裁剪用于特定用途。因此，取决于你需要什么 - 你应该验证单片机的配置。
|
||||
|
||||
如果你认为你知道比上述提到的更好的东西，请随意在下方评论来让我们知道。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/raspberry-pi-alternatives/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://itsfoss.com/best-linux-media-server/
|
||||
[2]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/raspberry-pi-alternatives.png?resize=800%2C450&ssl=1
|
||||
[3]: https://itsfoss.com/affiliate-policy/
|
||||
[4]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/omega-2-plus-e1555306748755-800x444.jpg?resize=800%2C444&ssl=1
|
||||
[5]: https://openwrt.org/
|
||||
[6]: https://amzn.to/2Xj8pkn
|
||||
[7]: https://onion.io/store/omega2p/
|
||||
[8]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/Jetson-Nano-e1555306350976-800x590.jpg?resize=800%2C590&ssl=1
|
||||
[9]: https://developer.nvidia.com/embedded/buy/jetson-nano-devkit
|
||||
[10]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/asus-tinker-board-s-e1555304945760-800x450.jpg?resize=800%2C450&ssl=1
|
||||
[11]: https://amzn.to/2XfkOFT
|
||||
[12]: https://en.wikipedia.org/wiki/MultiMediaCard
|
||||
[13]: https://www.asus.com/in/Single-Board-Computer/Tinker-Board-S/
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/clockwork-pi-e1555305016242-800x506.jpg?resize=800%2C506&ssl=1
|
||||
[15]: https://itsfoss.com/gameshell-console/
|
||||
[16]: https://www.clockworkpi.com/product-page/cpi-v3-1
|
||||
[17]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/arduino-mega-2560-e1555305257633.jpg?ssl=1
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||||
[18]: https://store.arduino.cc/usa/mega-2560-r3
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||||
[19]: https://amzn.to/2KCi041
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||||
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||||
[21]: https://www.pine64.org/?product=rock64-media-board-computer
|
||||
[22]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/odroid-xu4.jpg?fit=800%2C354&ssl=1
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||||
[23]: https://www.hardkernel.com/shop/odroid-xu4-special-price/
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||||
[24]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/PocketBeagle.jpg?fit=800%2C450&ssl=1
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||||
[25]: https://beagleboard.org/p/products/pocketbeagle
|
||||
[26]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/aml-libre.-e1555306237972-800x514.jpg?resize=800%2C514&ssl=1
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||||
[27]: https://libre.computer/
|
||||
[28]: https://amzn.to/2DpG3xl
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||||
[29]: https://libre.computer/products/boards/aml-s905x-cc/
|
||||
[30]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/banana-pi-m6.jpg?fit=800%2C389&ssl=1
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||||
[31]: http://www.banana-pi.org/m64.html
|
||||
[32]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/orange-pi-zero.jpg?fit=800%2C693&ssl=1
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||||
[33]: https://amzn.to/2IlI81g
|
||||
[34]: http://www.orangepi.org/orangepizero/index.html
|
||||
[35]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/khadas-vim-2-e1555306505640-800x563.jpg?resize=800%2C563&ssl=1
|
||||
[36]: https://amzn.to/2UDvrFE
|
||||
@ -1,5 +1,5 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
@ -7,79 +7,78 @@
|
||||
[#]: via: (https://opensource.com/article/19/4/detecting-malaria-deep-learning)
|
||||
[#]: author: (Dipanjan Sarkar https://opensource.com/users/djsarkar)
|
||||
|
||||
Detecting malaria with deep learning
|
||||
======
|
||||
Artificial intelligence combined with open source tools can improve
|
||||
diagnosis of the fatal disease malaria.
|
||||
使用深度学习检测疟疾
|
||||
==================
|
||||
人工智能结合开源硬件工具能够提升严重传染病疟疾的诊断。
|
||||
![][1]
|
||||
|
||||
Artificial intelligence (AI) and open source tools, technologies, and frameworks are a powerful combination for improving society. _"Health is wealth"_ is perhaps a cliche, yet it's very accurate! In this article, we will examine how AI can be leveraged for detecting the deadly disease malaria with a low-cost, effective, and accurate open source deep learning solution.
|
||||
人工智能（AI）和开源工具，技术，和框架是促进社会进步的强有力的结合。_“健康就是财富”_可能有点陈词滥调，但它却是非常准确的！在本篇文章，我们将测试 AI 是如何与低花费，有效，精确的开源深度学习方法一起被利用来检测致死的传染病疟疾。
|
||||
|
||||
While I am neither a doctor nor a healthcare researcher and I'm nowhere near as qualified as they are, I am interested in applying AI to healthcare research. My intent in this article is to showcase how AI and open source solutions can help malaria detection and reduce manual labor.
|
||||
我既不是一个医生，也不是一个医疗保健研究者，我也绝不像他们那样合格，我只是对将 AI 应用到医疗保健研究感兴趣。在这片文章中我的想法是展示 AI 和开源解决方案如何帮助疟疾检测和减少人工劳动的方法。
|
||||
|
||||
![Python and TensorFlow][2]
|
||||
|
||||
Python and TensorFlow: A great combo to build open source deep learning solutions
|
||||
Python and TensorFlow: 一个构建开源深度学习方法的很棒的结合
|
||||
|
||||
Thanks to the power of Python and deep learning frameworks like TensorFlow, we can build robust, scalable, and effective deep learning solutions. Because these tools are free and open source, we can build solutions that are very cost-effective and easily adopted and used by anyone. Let's get started!
|
||||
感谢 Python 的强大 和像 TensorFlow 这样的深度学习框架，我们能够构建鲁棒的，大规模的，有效的深度学习方法。因为这些工具是自由和开源的，我们能够构建低成本的能够轻易被任何人采纳和使用的解决方案。让我们开始吧！
|
||||
|
||||
### Motivation for the project
|
||||
### 项目动机
|
||||
|
||||
Malaria is a deadly, infectious, mosquito-borne disease caused by _Plasmodium_ parasites that are transmitted by the bites of infected female _Anopheles_ mosquitoes. There are five parasites that cause malaria, but two types— _P. falciparum_ and _P. vivax_ —cause the majority of the cases.
|
||||
疟疾是由_疟原虫_造成的致死的，有传染性的，蚊子传播的疾病，主要通过受感染的雌性按蚊叮咬传播。共有五种寄生虫能够造成疟疾，但是样例中的大多数是这两种类型- _恶性疟原虫_ 和 _间日疟原虫_ 造成的。
|
||||
|
||||
![Malaria heat map][3]
|
||||
![疟疾热图][3]
|
||||
|
||||
This map shows that malaria is prevalent around the globe, especially in tropical regions, but the nature and fatality of the disease is the primary motivation for this project.
|
||||
这个地图显示了疟疾在全球传播分布形势，尤其在热带地区，但疾病的性质和致命性是该项目的主要动机。
|
||||
|
||||
If an infected mosquito bites you, parasites carried by the mosquito enter your blood and start destroying oxygen-carrying red blood cells (RBC). Typically, the first symptoms of malaria are similar to a virus like the flu and they usually begin within a few days or weeks after the mosquito bite. However, these deadly parasites can live in your body for over a year without causing symptoms, and a delay in treatment can lead to complications and even death. Therefore, early detection can save lives.
|
||||
如果一个雌性蚊子咬了你，蚊子携带的寄生虫进入你的血液并且开始破坏携带氧气的红细胞（RBC）。通常，疟疾的最初症状类似于流感病毒，在蚊子叮咬后，他们通常在几天或几周内发作。然而，这些致死的寄生虫可以在你的身体里生存长达一年并且不会造成任何症状，延迟治疗可能造成并发症甚至死亡。因此，早期的检查能够挽救生命。
|
||||
|
||||
The World Health Organization's (WHO) [malaria facts][4] indicate that nearly half the world's population is at risk from malaria, and there are over 200 million malaria cases and approximately 400,000 deaths due to malaria every year. This is a motivatation to make malaria detection and diagnosis fast, easy, and effective.
|
||||
世界健康组织（WHO）的[疟疾事件][4]暗示世界近乎一半的人口面临疟疾的风险，有超过 2 亿 的疟疾病例，每年由于疟疾造成的死亡近乎 40 万。这是使疟疾检测和诊断快速，简单和有效的一个动机。
|
||||
|
||||
### Methods of malaria detection
|
||||
### 检测疟疾的方法
|
||||
|
||||
There are several methods that can be used for malaria detection and diagnosis. The paper on which our project is based, "[Pre-trained convolutional neural networks as feature extractors toward improved Malaria parasite detection in thin blood smear images][5]," by Rajaraman, et al., introduces some of the methods, including polymerase chain reaction (PCR) and rapid diagnostic tests (RDT). These two tests are typically used where high-quality microscopy services are not readily available.
|
||||
有几种方法能够用来检测和诊断疟疾。该文中的项目就是基于 Rajaraman，et al. 的论文：“[预先训练的卷积神经网络作为特征提取器，用于改善薄血涂片图像中的疟疾寄生虫检测][5]”，介绍了一些方法，包含聚合酶链反应（PCR）和快速诊断测试（RDT）。这两种测试通常在高质量的显微镜下使用，但这样的设备不是轻易能够获得的。
|
||||
|
||||
The standard malaria diagnosis is typically based on a blood-smear workflow, according to Carlos Ariza's article "[Malaria Hero: A web app for faster malaria diagnosis][6]," which I learned about in Adrian Rosebrock's "[Deep learning and medical image analysis with Keras][7]." I appreciate the authors of these excellent resources for giving me more perspective on malaria prevalence, diagnosis, and treatment.
|
||||
标准的疟疾诊断通常使基于血液涂片工作流的，根据 Carlos Ariza 的文章“[Malaria Hero: 一个更快诊断疟原虫的网络应用][6]”，我从中了解到 Adrian Rosebrock 的“[使用 Keras 的深度学习和医学图像分析][7]”。我感激这些优秀的资源的作者，让我在疟原虫预防，诊断和治疗方面有了更多的想法。
|
||||
|
||||
![Blood smear workflow for Malaria detection][8]
|
||||
![疟原虫检测的血涂片工作流程][8]
|
||||
|
||||
A blood smear workflow for Malaria detection
|
||||
一个疟原虫检测的血涂片工作流程
|
||||
|
||||
According to WHO protocol, diagnosis typically involves intensive examination of the blood smear at 100X magnification. Trained people manually count how many red blood cells contain parasites out of 5,000 cells. As the Rajaraman, et al., paper cited above explains:
|
||||
根据 WHO 草案，诊断通常包括对放大 100 倍的血涂片的集中检测。训练人们人工计数在 5000 个细胞中有多少红细胞中包含疟原虫。正如上述解释中引用的 Rajaraman， et al. 的论文：
|
||||
|
||||
> Thick blood smears assist in detecting the presence of parasites while thin blood smears assist in identifying the species of the parasite causing the infection (Centers for Disease Control and Prevention, 2012). The diagnostic accuracy heavily depends on human expertise and can be adversely impacted by the inter-observer variability and the liability imposed by large-scale diagnoses in disease-endemic/resource-constrained regions (Mitiku, Mengistu, and Gelaw, 2003). Alternative techniques such as polymerase chain reaction (PCR) and rapid diagnostic tests (RDT) are used; however, PCR analysis is limited in its performance (Hommelsheim, et al., 2014) and RDTs are less cost-effective in disease-endemic regions (Hawkes, Katsuva, and Masumbuko, 2009).
|
||||
> 薄血涂片帮助检测疟原虫的存在性并且帮助识别造成传染（疾病控制和抑制中心，2012）的物种。诊断准确性在很大程度上取决于人类的专业知识，并且可能受到观察者间差异和疾病流行/资源受限区域大规模诊断所造成的不利影响（Mitiku， Mengistu， and Gelaw， 2003）。可替代的技术是使用聚合酶链反应（PCR）和快速诊断测试（RDT）；然而，PCR 分析受限于它的性能（Hommelsheim， et al.， 2014），RDT 在疾病流行的地区成本效益低(Hawkes，Katsuva， and Masumbuko， 2009)。
|
||||
|
||||
Thus, malaria detection could benefit from automation using deep learning.
|
||||
因此，疟疾检测可能受益于使用机器学习的自动化。
|
||||
|
||||
### Deep learning for malaria detection
|
||||
### 疟原虫检测的深度学习
|
||||
|
||||
Manual diagnosis of blood smears is an intensive manual process that requires expertise in classifying and counting parasitized and uninfected cells. This process may not scale well, especially in regions where the right expertise is hard to find. Some advancements have been made in leveraging state-of-the-art image processing and analysis techniques to extract hand-engineered features and build machine learning-based classification models. However, these models are not scalable with more data being available for training and given the fact that hand-engineered features take a lot of time.
|
||||
人工诊断血涂片是一个加强的人工过程，需要专业知识来分类和计数被寄生虫感染的和未感染的细胞。这个过程可能不能很好的规模化，尤其在那些专业人士不足的地区。在利用最先进的图像处理和分析技术提取人工选取特征和构建基于机器学习的分类模型方面取得了一些进展。然而，这些模型不能大规模推广，因为没有更多的数据用来训练，并且人工选取特征需要花费很长时间。
|
||||
|
||||
Deep learning models, or more specifically convolutional neural networks (CNNs), have proven very effective in a wide variety of computer vision tasks. (If you would like additional background knowledge on CNNs, I recommend reading [CS231n Convolutional Neural Networks for Visual Recognition][9].) Briefly, the key layers in a CNN model include convolution and pooling layers, as shown in the following figure.
|
||||
深度学习模型，或者更具体地讲，卷积神经网络（CNNs），已经被证明在各种计算机视觉任务中非常有效。（如果你想有额外的关于 CNNs 的背景知识，我推荐你阅读[视觉识别的 CS2331n 卷积神经网络][9]。）简单地讲，CNN 模型的关键层包含卷积和池化层，正如下面图像显示。
|
||||
|
||||
![A typical CNN architecture][10]
|
||||
|
||||
A typical CNN architecture
|
||||
一个典型的 CNN 架构
|
||||
|
||||
Convolution layers learn spatial hierarchical patterns from data, which are also translation-invariant, so they are able to learn different aspects of images. For example, the first convolution layer will learn small and local patterns, such as edges and corners, a second convolution layer will learn larger patterns based on the features from the first layers, and so on. This allows CNNs to automate feature engineering and learn effective features that generalize well on new data points. Pooling layers helps with downsampling and dimension reduction.
|
||||
卷积层从数据中学习空间层级模式，它是平移不变的，因此它们能够学习不同方面的图像。例如，第一个卷积层将学习小的和本地图案，例如边缘和角落，第二个卷积层学习基于第一层的特征的更大的图案，等等。这允许 CNNs 自动化提取特征并且学习对于新数据点通用的有效的特征。池化层帮助下采样和降维。
|
||||
|
||||
Thus, CNNs help with automated and scalable feature engineering. Also, plugging in dense layers at the end of the model enables us to perform tasks like image classification. Automated malaria detection using deep learning models like CNNs could be very effective, cheap, and scalable, especially with the advent of transfer learning and pre-trained models that work quite well, even with constraints like less data.
|
||||
因此，CNNs 帮助自动化和规模化的特征工程。同样，在模型末尾加上密集层允许我们执行像图像分类这样的任务。使用像 CNNs 者的深度学习模型自动的疟疾检测可能非常有效，便宜和具有规模性，尤其是迁移学习和预训练模型效果非常好，甚至在少量数据的约束下。
|
||||
|
||||
The Rajaraman, et al., paper leverages six pre-trained models on a dataset to obtain an impressive accuracy of 95.9% in detecting malaria vs. non-infected samples. Our focus is to try some simple CNN models from scratch and a couple of pre-trained models using transfer learning to see the results we can get on the same dataset. We will use open source tools and frameworks, including Python and TensorFlow, to build our models.
|
||||
Rajaraman， et al. 的论文在一个数据集上利用六个预训练模型在检测疟疾 vs 无感染样本获取到令人吃惊的 95.9% 的准确率。我们的关注点是从头开始尝试一些简单的 CNN 模型和用一个预训练的训练模型使用迁移学习来查看我们能够从相同的数据集中得到什么。我们将使用开源工具和框架，包括 Python 和 TensorFlow，来构建我们的模型。
|
||||
|
||||
### The dataset
|
||||
### 数据集
|
||||
|
||||
The data for our analysis comes from researchers at the Lister Hill National Center for Biomedical Communications (LHNCBC), part of the National Library of Medicine (NLM), who have carefully collected and annotated the [publicly available dataset][11] of healthy and infected blood smear images. These researchers have developed a mobile [application for malaria detection][12] that runs on a standard Android smartphone attached to a conventional light microscope. They used Giemsa-stained thin blood smear slides from 150 _P. falciparum_ -infected and 50 healthy patients, collected and photographed at Chittagong Medical College Hospital, Bangladesh. The smartphone's built-in camera acquired images of slides for each microscopic field of view. The images were manually annotated by an expert slide reader at the Mahidol-Oxford Tropical Medicine Research Unit in Bangkok, Thailand.
|
||||
我们分析的数据来自 Lister Hill 国家生物医学交流中心（LHNCBC），国家医学图书馆（NLM）的一部分，他们细心收集和标记了健康和受感染的血涂片图像的[公众可获得的数据集][11]。这些研究者已经开发了一个运行在 Android 智能手机的移动[疟疾检测应用][12]，连接到一个传统的光学显微镜。它们使用 吉姆萨染液 将 150 个受恶性疟原虫感染的和 50 个健康病人的薄血涂片染色，这些薄血涂片是在孟加拉的吉大港医学院附属医院收集和照相的。使用智能手机的内置相机获取每个显微镜视窗内的图像。这些图片由在泰国曼谷的马希多-牛津热带医学研究所的一个专家使用幻灯片阅读器标记的。
|
||||
|
||||
Let's briefly check out the dataset's structure. First, I will install some basic dependencies (based on the operating system being used).
|
||||
让我们简洁的查看数据集的结构。首先，我将安装一些基础的依赖（基于使用的操作系统）。
|
||||
|
||||
![Installing dependencies][13]
|
||||
|
||||
I am using a Debian-based system on the cloud with a GPU so I can run my models faster. To view the directory structure, we must install the tree dependency (if we don't have it) using **sudo apt install tree**.
|
||||
我使用的是云上的带有一个 GPU 的基于 Debian 的操作系统，这样我能更快的运行我的模型。为了查看目录结构，我们必须安装 tree 依赖（如果我们没有安装的话）使用 **sudo apt install tree**。
|
||||
|
||||
![Installing the tree dependency][14]
|
||||
|
||||
We have two folders that contain images of cells, infected and healthy. We can get further details about the total number of images by entering:
|
||||
我们有两个文件夹包含血细胞的图像，包括受感染的和健康的。我们可以获取关于图像总数更多的细节通过输入：
|
||||
|
||||
|
||||
```
|
||||
@ -98,7 +97,7 @@ len(infected_files), len(healthy_files)
|
||||
(13779, 13779)
|
||||
```
|
||||
|
||||
It looks like we have a balanced dataset with 13,779 malaria and 13,779 non-malaria (uninfected) cell images. Let's build a data frame from this, which we will use when we start building our datasets.
|
||||
看起来我们有一个平衡的 13,779 张疟疾的 和 13,779 张非疟疾的（健康的）血细胞图像。让我们根据这些构建数据帧，我们将用这些数据帧来构建我们的数据集。
|
||||
|
||||
|
||||
```
|
||||
@ -117,9 +116,9 @@ files_df.head()
|
||||
|
||||
![Datasets][15]
|
||||
|
||||
### Build and explore image datasets
|
||||
### 构建和参所图像数据集
|
||||
|
||||
To build deep learning models, we need training data, but we also need to test the model's performance on unseen data. We will use a 60:10:30 split for train, validation, and test datasets, respectively. We will leverage the train and validation datasets during training and check the performance of the model on the test dataset.
|
||||
为了构建深度学习模型，我们需要训练数据，但是我们还需要使用不可见的数据测试模型的性能。相应的，我们将使用 60：10：30 的划分用于训练，验证和测试数据集。我们将在训练期间应用训练和验证数据集并用测试数据集来检查模型的性能。
|
||||
|
||||
|
||||
```
|
||||
@ -143,7 +142,7 @@ Val: Counter({'healthy': 970, 'malaria': 959})
|
||||
Test: Counter({'malaria': 4193, 'healthy': 4075})
|
||||
```
|
||||
|
||||
The images will not be of equal dimensions because blood smears and cell images vary based on the human, the test method, and the orientation of the photo. Let's get some summary statistics of our training dataset to determine the optimal image dimensions (remember, we don't touch the test dataset at all!).
|
||||
这些图片维度并不相同，因此血涂片和细胞图像是基于人类，测试方法，图片的朝向。让我们总结我们的训练数据集的统计信息来决定最佳的图像维度（牢记，我们根本不会碰测试数据集）。
|
||||
|
||||
|
||||
```
|
||||
@ -183,7 +182,7 @@ Median Dimensions: [130. 130. 3.]
|
||||
Max Dimensions: [385 394 3]
|
||||
```
|
||||
|
||||
We apply parallel processing to speed up the image-read operations and, based on the summary statistics, we will resize each image to 125x125 pixels. Let's load up all of our images and resize them to these fixed dimensions.
|
||||
我们应用并行处理来加速图像读取，并且在总结统计时，我们将重新调整每幅图片到 125x125 像素。让我们载入我们所有的图像并重新调整它们为这些固定的大小。
|
||||
|
||||
|
||||
```
|
||||
@ -246,7 +245,7 @@ ThreadPoolExecutor-1_8: working on img num: 8267
|
||||
((17361, 125, 125, 3), (1929, 125, 125, 3), (8268, 125, 125, 3))
|
||||
```
|
||||
|
||||
We leverage parallel processing again to speed up computations pertaining to image load and resizing. Finally, we get our image tensors of the desired dimensions, as depicted in the preceding output. We can now view some sample cell images to get an idea of how our data looks.
|
||||
我们再次应用并行处理来加速有关图像载入和重新调整大小。最终，我们获得了想要的维度的图片张量，正如之前描述的。我们现在查看一些血细胞图像样本来对我们的数据什么样有个印象。
|
||||
|
||||
|
||||
```
|
||||
@ -267,9 +266,9 @@ plt.xticks([]) , plt.yticks([])
|
||||
|
||||
![Malaria cell samples][16]
|
||||
|
||||
Based on these sample images, we can see some subtle differences between malaria and healthy cell images. We will make our deep learning models try to learn these patterns during model training.
|
||||
基于这些样本图像，我们看到一些疟疾和健康细胞图像的细微不同。我们将使我们的深度学习模型试图在模型训练中学习这些模式。
|
||||
|
||||
Before can we start training our models, we must set up some basic configuration settings.
|
||||
开始我们的模型训练前，我们必须建立一些基础的配置设置。
|
||||
|
||||
|
||||
```
|
||||
@ -295,7 +294,7 @@ print(train_labels[:6], train_labels_enc[:6])
|
||||
['malaria' 'malaria' 'malaria' 'healthy' 'healthy' 'malaria'] [1 1 1 0 0 1]
|
||||
```
|
||||
|
||||
We fix our image dimensions, batch size, and epochs and encode our categorical class labels. The alpha version of TensorFlow 2.0 was released in March 2019, and this exercise is the perfect excuse to try it out.
|
||||
我们修复我们的图像维度，批大小，和历元并编码我们的分类类标签。TensorFlow 2.0 于 2019 年三月发布，这个练习是非常好的借口来试用它。
|
||||
|
||||
|
||||
```
|
||||
@ -311,13 +310,13 @@ tf.__version__
|
||||
'2.0.0-alpha0'
|
||||
```
|
||||
|
||||
### Deep learning model training
|
||||
### 深度学习训练
|
||||
|
||||
In the model training phase, we will build three deep learning models, train them with our training data, and compare their performance using the validation data. We will then save these models and use them later in the model evaluation phase.
|
||||
在模型训练阶段，我们将构建三个深度训练模型，使用我们的训练集训练，使用验证数据比较它们的性能。我们然后保存这些模型并在之后的模型评估阶段使用它们。
|
||||
|
||||
#### Model 1: CNN from scratch
|
||||
#### 模型 1：从头开始的 CNN
|
||||
|
||||
Our first malaria detection model will build and train a basic CNN from scratch. First, let's define our model architecture.
|
||||
我们的第一个疟疾检测模型将从头开始构建和训练一个基础的 CNN。首先，让我们定义我们的模型架构，
|
||||
|
||||
|
||||
```
|
||||
@ -376,7 +375,7 @@ Non-trainable params: 0
|
||||
_________________________________________________________________
|
||||
```
|
||||
|
||||
Based on the architecture in this code, our CNN model has three convolution and pooling layers, followed by two dense layers, and dropouts for regularization. Let's train our model.
|
||||
基于这些代码的架构，我们的 CNN 模型有三个卷积和一个池化层，跟随两个致密层，以及用于正则化的丢失。让我们训练我们的模型。
|
||||
|
||||
|
||||
```
|
||||
@ -411,7 +410,7 @@ Epoch 25/25
|
||||
17361/17361 [====] - 30s 2ms/sample - loss: 0.0034 - accuracy: 0.9994 - val_loss: 0.3699 - val_accuracy: 0.9559
|
||||
```
|
||||
|
||||
We get a validation accuracy of 95.6%, which is pretty good, although our model looks to be overfitting slightly (based on looking at our training accuracy, which is 99.9%). We can get a clear perspective on this by plotting the training and validation accuracy and loss curves.
|
||||
我们获得了 95.6% 的验证精确率，这很好，尽管我们的模型看起来有些过拟合（通过查看我们的训练精确度，是 99.9%）。通过绘制训练和验证的精度和损失曲线，我们可以清楚地看到这一点。
|
||||
|
||||
|
||||
```
|
||||
@ -440,47 +439,47 @@ l2 = ax2.legend(loc="best")
|
||||
|
||||
![Learning curves for basic CNN][17]
|
||||
|
||||
Learning curves for basic CNN
|
||||
基础 CNN 学习曲线
|
||||
|
||||
We can see after the fifth epoch that things don't seem to improve a whole lot overall. Let's save this model for future evaluation.
|
||||
我们可以看在在第五个历元，情况并没有改善很多。让我们保存这个模型用于将来的评估。
|
||||
|
||||
|
||||
```
|
||||
`model.save('basic_cnn.h5')`
|
||||
```
|
||||
|
||||
#### Deep transfer learning
|
||||
#### 深度迁移学习
|
||||
|
||||
Just like humans have an inherent capability to transfer knowledge across tasks, transfer learning enables us to utilize knowledge from previously learned tasks and apply it to newer, related ones, even in the context of machine learning or deep learning. If you are interested in doing a deep-dive on transfer learning, you can read my article "[A comprehensive hands-on guide to transfer learning with real-world applications in deep learning][18]" and my book [_Hands-On Transfer Learning with Python_][19].
|
||||
就像人类有与生俱来的能力在不同任务间传输知识，迁移学习允许我们利用从以前任务学到的知识用到新的任务，相关的任务，甚至在机器学习或深度学习的上下文中。如果想深入探究迁移学习，你应该看我的文章“[一个易于理解与现实应用一起学习深度学习中的迁移学习的指导实践][18]”和我的书[ Python 迁移学习实践][19]。
|
||||
|
||||
![Ideas for deep transfer learning][20]
|
||||
![深度迁移学习的想法][20]
|
||||
|
||||
The idea we want to explore in this exercise is:
|
||||
在这篇实践中我们想要探索的想法是：
|
||||
|
||||
> Can we leverage a pre-trained deep learning model (which was trained on a large dataset, like ImageNet) to solve the problem of malaria detection by applying and transferring its knowledge in the context of our problem?
|
||||
> 在我们的问题上下文中，我们能够利用一个预训练深度学习模型（在大数据集上训练的，像 ImageNet）通过应用和迁移知识来解决疟疾检测的问题吗？
|
||||
|
||||
We will apply the two most popular strategies for deep transfer learning.
|
||||
我们将应用两个深度迁移学习的最流行的策略。
|
||||
|
||||
* Pre-trained model as a feature extractor
|
||||
* Pre-trained model with fine-tuning
|
||||
* 预训练模型作为特征提取器
|
||||
* 微调的预训练模型
|
||||
|
||||
|
||||
|
||||
We will be using the pre-trained VGG-19 deep learning model, developed by the Visual Geometry Group (VGG) at the University of Oxford, for our experiments. A pre-trained model like VGG-19 is trained on a huge dataset ([ImageNet][21]) with a lot of diverse image categories. Therefore, the model should have learned a robust hierarchy of features, which are spatial-, rotational-, and translation-invariant with regard to features learned by CNN models. Hence, the model, having learned a good representation of features for over a million images, can act as a good feature extractor for new images suitable for computer vision problems like malaria detection. Let's discuss the VGG-19 model architecture before unleashing the power of transfer learning on our problem.
|
||||
我们将使用预训练的 VGG-19 深度训练模型，由剑桥大学的视觉几何组（VGG）开发，作为我们的实验。一个像 VGG-19 的预训练模型在一个大的数据集上使用了很多不同的图像分类训练（[Imagenet][21]）。因此，这个模型应该已经学习到了鲁棒的特征层级结构，相对于你的 CNN 模型学到的特征，是空间不变的，转动不变的，平移不变的。因此，这个模型，已经从百万幅图片中学习到了一个好的特征显示，对于像疟疾检测这样的计算机视觉问题，可以作为一个好的合适新图像的特征提取器。在我们的问题中释放迁移学习的能力之前，让我们先讨论 VGG-19 模型。
|
||||
|
||||
##### Understanding the VGG-19 model
|
||||
##### 理解 VGG-19 模型
|
||||
|
||||
The VGG-19 model is a 19-layer (convolution and fully connected) deep learning network built on the ImageNet database, which was developed for the purpose of image recognition and classification. This model was built by Karen Simonyan and Andrew Zisserman and is described in their paper "[Very deep convolutional networks for large-scale image recognition][22]." The architecture of the VGG-19 model is:
|
||||
VGG-19 模型是一个构建在 ImageNet 数据库之上的 19 层（卷积和全连接的）的深度学习网络，该数据库为了图像识别和分类的目的而开发。该模型由 Karen Simonyan 和 Andrew Zisserman 构建，在它们的论文”[大规模图像识别的非常深的卷积网络][22]“中描述。VGG-19 的架构模型是：
|
||||
|
||||
![VGG-19 Model Architecture][23]
|
||||
![VGG-19 模型架构][23]
|
||||
|
||||
You can see that we have a total of 16 convolution layers using 3x3 convolution filters along with max pooling layers for downsampling and two fully connected hidden layers of 4,096 units in each layer followed by a dense layer of 1,000 units, where each unit represents one of the image categories in the ImageNet database. We do not need the last three layers since we will be using our own fully connected dense layers to predict malaria. We are more concerned with the first five blocks so we can leverage the VGG model as an effective feature extractor.
|
||||
你可以看到我们总共有 16 个使用 3x3 卷积过滤器的卷积层，与最大的池化层来下采样，和由 4096 个单元组成的两个全连接的隐藏层，每个隐藏层之后跟随一个由 1000 个单元组成的致密层，每个单元代表 ImageNet 数据库中的一个分类。我们不需要最后三层，因为我们将使用我们自己的全连接致密层来预测疟疾。我们更关心前五块，因此我们可以利用 VGG 模型作为一个有效的特征提取器。
|
||||
|
||||
We will use one of the models as a simple feature extractor by freezing the five convolution blocks to make sure their weights aren't updated after each epoch. For the last model, we will apply fine-tuning to the VGG model, where we will unfreeze the last two blocks (Block 4 and Block 5) so that their weights will be updated in each epoch (per batch of data) as we train our own model.
|
||||
我们将使用模型之一作为一个简单的特征提取器通过冻结五个卷积块的方式来确保它们的位权在每个时期后不会更新。对于最后一个模型，我们会应用微调到 VGG 模型，我们会解冻最后两个块（第 4 和第 5）因此当我们训练我们的模型时，它们的位权在每个时期（每批数据）被更新。
|
||||
|
||||
#### Model 2: Pre-trained model as a feature extractor
|
||||
#### 模型 2：预训练的模型作为一个特征提取器
|
||||
|
||||
For building this model, we will leverage TensorFlow to load up the VGG-19 model and freeze the convolution blocks so we can use them as an image feature extractor. We will plug in our own dense layers at the end to perform the classification task.
|
||||
为了构建这个模型，我们将利用 TensorFlow 载入 VGG-19 模型并且冻结卷积块因此我们用够将他们用作特征提取器。我们插入我们自己的致密层在末尾来执行分类任务。
|
||||
|
||||
|
||||
```
|
||||
@ -541,7 +540,7 @@ Non-trainable params: 20,024,384
|
||||
_________________________________________________________________
|
||||
```
|
||||
|
||||
It is evident from this output that we have a lot of layers in our model and we will be using the frozen layers of the VGG-19 model as feature extractors only. You can use the following code to verify how many layers in our model are indeed trainable and how many total layers are present in our network.
|
||||
输出是很明白的，在我们的模型中我们有了很多层，我们将只利用 VGG-19 模型的冻结层作为特征提取器。你可以使用下列代码来验证我们的模型有多少层是实际训练的，我们的网络中总共存在多少层。
|
||||
|
||||
|
||||
```
|
||||
@ -554,22 +553,22 @@ Total Layers: 28
|
||||
Total trainable layers: 6
|
||||
```
|
||||
|
||||
We will now train our model using similar configurations and callbacks to the ones we used in our previous model. Refer to [my GitHub repository][24] for the complete code to train the model. We observe the following plots showing the model's accuracy and loss.
|
||||
我们将使用和我们之前的模型相似的配置和回调来训练我们的模型。参考 [我的 GitHub 仓库][24] 获取训练模型的完整代码。我们观察下列显示模型精确度和损失曲线。
|
||||
|
||||
![Learning curves for frozen pre-trained CNN][25]
|
||||
|
||||
Learning curves for frozen pre-trained CNN
|
||||
冻结的预训练的 CNN 的学习曲线
|
||||
|
||||
This shows that our model is not overfitting as much as our basic CNN model, but the performance is slightly less than our basic CNN model. Let's save this model for future evaluation.
|
||||
这显示了我们的模型没有像我们的基础 CNN 模型那样过拟合，但是性能有点不如我们的基础的 CNN 模型。让我们保存这个模型用户将来的评估。
|
||||
|
||||
|
||||
```
|
||||
`model.save('vgg_frozen.h5')`
|
||||
```
|
||||
|
||||
#### Model 3: Fine-tuned pre-trained model with image augmentation
|
||||
#### 模型 3：使用图像增强来微调预训练的模型
|
||||
|
||||
In our final model, we will fine-tune the weights of the layers in the last two blocks of our pre-trained VGG-19 model. We will also introduce the concept of image augmentation. The idea behind image augmentation is exactly as the name sounds. We load in existing images from our training dataset and apply some image transformation operations to them, such as rotation, shearing, translation, zooming, and so on, to produce new, altered versions of existing images. Due to these random transformations, we don't get the same images each time. We will leverage an excellent utility called **ImageDataGenerator** in **tf.keras** that can help build image augmentors.
|
||||
在我们的最后一个模型中，我们微调预定义好的 VGG-19 模型的最后两个块中层的位权。我们同样引入图像增强的概念。图像增强背后的想法和名字一样。我们从训练数据集中载入已存在的图像，并且应用转换操作，例如旋转，裁剪，转换，放大缩小，等等，来产生新的，改变的版本。由于这些随机的转换，我们每次获取到的图像不一样。我们将应用一个在 **tf.keras** 的优秀的工具叫做 **ImageDataGenerator** 来帮助构建图像增强器。
|
||||
|
||||
|
||||
```
|
||||
@ -588,7 +587,7 @@ train_generator = train_datagen.flow(train_data, train_labels_enc, batch_size=BA
|
||||
val_generator = val_datagen.flow(val_data, val_labels_enc, batch_size=BATCH_SIZE, shuffle=False)
|
||||
```
|
||||
|
||||
We will not apply any transformations on our validation dataset (except for scaling the images, which is mandatory) since we will be using it to evaluate our model performance per epoch. For a detailed explanation of image augmentation in the context of transfer learning, feel free to check out my [article][18] cited above. Let's look at some sample results from a batch of image augmentation transforms.
|
||||
我们不会应用任何转换在我们的验证数据集上（除非是调整大小，它是强制性适应的）因为我们将在每个时期来评估我们的模型性能。对于在传输学习上下文中的图像增强的详细解释，请自由查看我们上述引用的[文章][18]。让我们从一批图像增强转换中查看一些样本结果。
|
||||
|
||||
|
||||
```
|
||||
@ -603,7 +602,7 @@ l = [ax[i].imshow(sample[i][0][0]) for i in range(0,5)]
|
||||
|
||||
![Sample augmented images][26]
|
||||
|
||||
You can clearly see the slight variations of our images in the preceding output. We will now build our deep learning model, making sure the last two blocks of the VGG-19 model are trainable.
|
||||
你可以清晰的看到与之前的输出中我们图像的轻微变化。我们现在构建我们的学习模型，确保 VGG-19 模型的最后两块是可以训练的。
|
||||
|
||||
|
||||
```
|
||||
@ -644,7 +643,7 @@ Total Layers: 28
|
||||
Total trainable layers: 16
|
||||
```
|
||||
|
||||
We reduce the learning rate in our model since we don't want to make to large weight updates to the pre-trained layers when fine-tuning. The model's training process will be slightly different since we are using data generators, so we will be leveraging the **fit_generator(…)** function.
|
||||
在我们的模型中我们降低了学习率，因为我们微调的时候不想在预训练的数据集上做大的位权更新。模型的训练过程可能有轻微的不同，因为我们使用了数据生成器，因此我们应用了 **fit_generator(...)** 函数。
|
||||
|
||||
|
||||
```
|
||||
@ -672,24 +671,24 @@ Epoch 25/25
|
||||
271/271 [====] - 128s 473ms/step - loss: 0.0792 - accuracy: 0.9729 - val_loss: 0.1127 - val_accuracy: 0.9641
|
||||
```
|
||||
|
||||
This looks to be our best model yet. It gives us a validation accuracy of almost 96.5% and, based on the training accuracy, it doesn't look like our model is overfitting as much as our first model. This can be verified with the following learning curves.
|
||||
这看起来是我们的最好的模型。它给了我们近乎 96.5% 的验证精确率，基于训练精度，它看起来不像我们的第一个模型那样过拟合。这可以通过下列的学习曲线验证。
|
||||
|
||||
![Learning curves for fine-tuned pre-trained CNN][27]
|
||||
|
||||
Learning curves for fine-tuned pre-trained CNN
|
||||
微调预训练的 CNN 的学习曲线
|
||||
|
||||
Let's save this model so we can use it for model evaluation on our test dataset.
|
||||
让我们保存这个模型，因此我们能够在测试集上使用。
|
||||
|
||||
|
||||
```
|
||||
`model.save('vgg_finetuned.h5')`
|
||||
```
|
||||
|
||||
This completes our model training phase. We are now ready to test the performance of our models on the actual test dataset!
|
||||
这完成了我们的模型训练阶段。我们准备好在测试集上测试我们模型的性能。
|
||||
|
||||
### Deep learning model performance evaluation
|
||||
### 深度学习模型性能评估
|
||||
|
||||
We will evaluate the three models we built in the training phase by making predictions with them on the data from our test dataset—because just validation is not enough! We have also built a nifty utility module called **model_evaluation_utils** , which we can use to evaluate the performance of our deep learning models with relevant classification metrics. The first step is to scale our test data.
|
||||
我们将评估我们在训练阶段构建的三个模型，通过在我们的测试集上做预测，因为仅仅验证是不够的！我们同样构建了一个检测工具模块叫做 **model_evaluation_utils**，我们可以使用相关分类指标用来评估使用我们深度学习模型的性能。第一步是测量我们的数据集。
|
||||
|
||||
|
||||
```
|
||||
@ -700,7 +699,7 @@ test_imgs_scaled.shape, test_labels.shape
|
||||
((8268, 125, 125, 3), (8268,))
|
||||
```
|
||||
|
||||
The next step involves loading our saved deep learning models and making predictions on the test data.
|
||||
下一步包括载入我们保存的深度学习模型，在测试集上预测。
|
||||
|
||||
|
||||
```
|
||||
@ -722,7 +721,7 @@ vgg_ft_pred_labels = le.inverse_transform([1 if pred > 0.5 else 0
|
||||
for pred in vgg_ft_preds.ravel()])
|
||||
```
|
||||
|
||||
The final step is to leverage our **model_evaluation_utils** module and check the performance of each model with relevant classification metrics.
|
||||
下一步是应用我们的 **model_evaluation_utils** 模块根据相应分类指标来检查每个模块的性能。
|
||||
|
||||
|
||||
```
|
||||
@ -739,15 +738,15 @@ index=['Basic CNN', 'VGG-19 Frozen', 'VGG-19 Fine-tuned'])
|
||||
|
||||
![Model accuracy][28]
|
||||
|
||||
It looks like our third model performs best on the test dataset, giving a model accuracy and an F1-score of 96%, which is pretty good and quite comparable to the more complex models mentioned in the research paper and articles we mentioned earlier.
|
||||
看起来我们的第三个模型在我们的测试集上执行的最好，给出了一个模型精确性为 96% 的 F1得分，比起上述我们早期引用的研究论文和文章中提及的复杂的模型是相当好的。
|
||||
|
||||
### Conclusion
|
||||
### 总结
|
||||
|
||||
Malaria detection is not an easy procedure, and the availability of qualified personnel around the globe is a serious concern in the diagnosis and treatment of cases. We looked at an interesting real-world medical imaging case study of malaria detection. Easy-to-build, open source techniques leveraging AI can give us state-of-the-art accuracy in detecting malaria, thus enabling AI for social good.
|
||||
疟疾检测不是一个简单的程序，全球的合格的人员的可获得性在样例诊断和治疗当中是一个严重的问题。我们看到一个关于疟疾的有趣的真实世界的医学影像案例。易于构建的，开源的技术利用 AI 在检测疟疾方面可以给我们最先进的精确性，因此允许 AI 对社会是有益的。
|
||||
|
||||
I encourage you to check out the articles and research papers mentioned in this article, without which it would have been impossible for me to conceptualize and write it. If you are interested in running or adopting these techniques, all the code used in this article is available on [my GitHub repository][24]. Remember to download the data from the [official website][11].
|
||||
我鼓励你检查这片文章中提到的文章和研究论文，没有它们，我就不能形成概念并写出来。如果你对运行和采纳这些技术感兴趣，本篇文章所有的代码都可以在[我的 GitHub 仓库][24]获得。记得从[官方网站][11]下载数据。
|
||||
|
||||
Let's hope for more adoption of open source AI capabilities in healthcare to make it less expensive and more accessible for everyone around the world!
|
||||
让我们希望在健康医疗方面更多的采纳开源的 AI 能力，使它在世界范围内变得便宜些，易用些。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -755,7 +754,7 @@ via: https://opensource.com/article/19/4/detecting-malaria-deep-learning
|
||||
|
||||
作者：[Dipanjan (DJ) Sarkar (Red Hat)][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
@ -1,244 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (arrowfeng)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How to Install MySQL in Ubuntu Linux)
|
||||
[#]: via: (https://itsfoss.com/install-mysql-ubuntu/)
|
||||
[#]: author: (Sergiu https://itsfoss.com/author/sergiu/)
|
||||
|
||||
怎样在Ubuntu Linux上安装MySQL
|
||||
======
|
||||
|
||||
_**简要: 本教程教你如何在基于Ubuntu的Linux发行版上安装MySQL。对于首次使用的用户，你将会学习到如何验证你的安装和第一次怎样去连接MySQL。**_
|
||||
|
||||
**[MySQL][1]** 是一个典型的数据库管理系统。它被用于许多技术栈中，包括流行的 **[LAMP][2]** (Linux, Apache, MySQL, PHP) 技术栈. 它已经被证实了其稳定性。 另一个让**MySQL**受欢迎的原因是它是开源的。
|
||||
|
||||
**MySQL** 是 **关系型数据库** (基本上是 **表格 数据** ). 以这种方式它很容易去存储，组织和访问数据。它使用**SQL**( **结构化查询语言** )来管理数据。
|
||||
|
||||
这这篇文章中，我将向你展示如何在Ubuntu 18.04安装和使用MySQL 8.0。让我们一起来看看吧！
|
||||
|
||||
|
||||
### 在Ubuntu上安装MySQL
|
||||
|
||||
![][3]
|
||||
|
||||
我将会介绍两种在Ubuntu18.04上安装**MySQL**的方法：
|
||||
1. 从Ubuntu仓库上安装MySQL。非常简单，但不是最新版（5.7）
|
||||
2. 从官方仓库安装MySQL。你将额外增加一些步处理过程，但不用担心。你将会拥有最新版的MySQL（8.0）
|
||||
|
||||
|
||||
有必要的时候，我将会提供屏幕截图去引导你。但这边文章中的大部分步骤，我将直接在**终端**（**默认热键**: CTRL+ALT+T）输入命令。别害怕它！
|
||||
|
||||
#### 方法 1. 从Ubuntu仓库安装MySQL
|
||||
|
||||
首先，输入下列命令确保你的仓库已经被更新：
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
```
|
||||
|
||||
现在, 安装 **MySQL 5.7** , 简单输入下列命令:
|
||||
|
||||
```
|
||||
sudo apt install mysql-server -y
|
||||
```
|
||||
|
||||
就是这样！简单且高效。
|
||||
|
||||
#### 方法 2. 使用官方仓库安装MySQL
|
||||
|
||||
虽然这个方法多了一些步骤，但我将逐一介绍，并尝试写下清晰的笔记。
|
||||
|
||||
首先浏览官方的MySQL网站[download page][4]。
|
||||
|
||||
![][5]
|
||||
|
||||
在这，选择**DEB Package**点击**download link**。
|
||||
|
||||
![][6]
|
||||
|
||||
滑到有关于Oracle网站信息的底部，右键 **No thanks, just start my download.** ，然后选择 **Copy link location**。
|
||||
|
||||
|
||||
现在回到终端，我们将使用 **[Curl][7]** 命令去下载这个软件包：
|
||||
|
||||
Now go back to the terminal. We’ll [use][7] **[Curl][7]** [command][7] to the download the package:
|
||||
|
||||
```
|
||||
curl -OL https://dev.mysql.com/get/mysql-apt-config_0.8.12-1_all.deb
|
||||
```
|
||||
|
||||
**<https://dev.mysql.com/get/mysql-apt-config\_0.8.12-1\_all.deb>** 是我刚刚从网页上复制的链接。根据当前的MySQL版本，它有可能不同。让我们使用**dpkg**去开始安装MySQL：
|
||||
|
||||
```
|
||||
sudo dpkg -i mysql-apt-config*
|
||||
```
|
||||
|
||||
更新你的仓库:
|
||||
|
||||
```
|
||||
sudo apt update
|
||||
```
|
||||
|
||||
要实际安装MySQL,我们将使用像第一个方法中同样的命令来安装：
|
||||
|
||||
```
|
||||
sudo apt install mysql-server -y
|
||||
```
|
||||
|
||||
这样做会在你的终端中打开**包配置**的提示。使用**向下箭头**选择 **Ok**选项。
|
||||
|
||||
![][8]
|
||||
|
||||
点击 **Enter**.这应该会提示你输入**password**：你的基本上是在为MySQL设置root密码。不要与[Ubuntu的root密码混淆][9]。
|
||||
|
||||
![][10]
|
||||
|
||||
输入密码然后点击**Tab**键去选择 **< Ok>**.点击**Enter**键，你将**重新输入** **password**。操作完之后，再次键入**Tab**去选择 **< Ok>**。按下**Enter**键。
|
||||
|
||||
![][11]
|
||||
|
||||
一些关于MySQL Server的配置信息将会展示。再次按下**Tab**去选择 **< Ok>** 和按下 **Enter**键：
|
||||
|
||||
![][12]
|
||||
|
||||
这里你需要去选择**default authentication plugin**。确保**Use Strong Password Encryption**被选择。按下**Tab**键和**Enter**键。
|
||||
|
||||
就是这样！你已经成功地安装了MySQL。
|
||||
|
||||
#### 验证你的MySQL安装
|
||||
|
||||
要验证MySQL已经正确安装，使用下列命令：
|
||||
|
||||
```
|
||||
sudo systemctl status mysql.service
|
||||
```
|
||||
|
||||
这将展示一些关于MySQL服务的信息：
|
||||
|
||||
![][13]
|
||||
|
||||
你应该在那里看到 **Active: active (running)** 。如果你没有看到，使用下列命令去开始这个 **service**：
|
||||
|
||||
```
|
||||
sudo systemctl start mysql.service
|
||||
```
|
||||
|
||||
#### 配置/保护 MySQL
|
||||
|
||||
对于刚安装的MySQL，你应该运行它提供的安全相关的更新命令。就是：
|
||||
|
||||
```
|
||||
sudo mysql_secure_installation
|
||||
```
|
||||
|
||||
这样做首先会询问你是否想使用**VALIDATE PASSWORD COMPONENT**.如果你想使用它，你将不得不去选择一个最小密码强度( **0 – Low, 1 – Medium, 2 – High** )。你将无法输入任何不遵守所选规则的密码。如果你没有使用强密码的习惯（本应该使用），这可能会配上用场。如果你认为它可能有帮助，那你就键入**y** 或者 **Y**，按下**Enter**键，然后为你的密码选择一个**强度等级**和输入一个你想使用的。如果成功，你将继续**securing**过程；否则你将重新输入一个密码。
|
||||
|
||||
|
||||
但是，如果你不想要此功能（我不会），只需按**Enter**或**任何其他键**即可跳过使用它。
|
||||
|
||||
对于其他选项，我建议**开启**他们(对于每一步输入**y** 或者 **Y** 和按下**Enter**)。他们是（以这样的顺序）：**remove anonymous user, disallow root login remotely, remove test database and access to it, reload privilege tables now**.
|
||||
MySQL Server上
|
||||
#### 链接与断开MySQL Server
|
||||
|
||||
为了去运行SQL查询，你首先不得不使用MySQL链接到MySQL服务并使用MySQL提示符。
|
||||
To be able to run SQL queries, you’ll first have to connect to the server using MySQL and use the MySQL prompt. 执行此操作的命令是：
|
||||
|
||||
```
|
||||
mysql -h host_name -u user -p
|
||||
```
|
||||
|
||||
* **-h** 被用来指定一个 **主机名** （如果这个服务被安装到其他机器上，那么会有用；如果没有，忽略它）
|
||||
* **-u** 指定登录的 **用户**
|
||||
* **-p** 指定你想输入的 **密码**.
|
||||
|
||||
|
||||
|
||||
你能通过在最右边输入 **-p**后直接输入密码在命令行，但这样做是不建议的（为了安全原因），如果用户**test_user** 的密码是**1234**，那么你可以尝试去连接你正在使用的机器上的mysql，你应该这样使用：
|
||||
|
||||
```
|
||||
mysql -u test_user -p1234
|
||||
```
|
||||
|
||||
如果你成功输入了必要的参数，你将会收到由**MySQL shell 提示符**提供的欢迎（ **mysql >** ）：
|
||||
![][14]
|
||||
|
||||
要从服务端断开连接和离开mysql提示符，输入：
|
||||
|
||||
```
|
||||
QUIT
|
||||
```
|
||||
|
||||
输入**quit** （MySQL不区分大小写）或者 **\q**也能工作。按下**Enter**退出。
|
||||
|
||||
你使用简单的命令也能输出关于版本的信息：
|
||||
|
||||
```
|
||||
sudo mysqladmin -u root version -p
|
||||
```
|
||||
|
||||
如果你想看 **选项列表**，使用：
|
||||
|
||||
```
|
||||
mysql --help
|
||||
```
|
||||
|
||||
#### 卸载 MySQL
|
||||
|
||||
|
||||
|
||||
如果您决定要使用较新版本或只是想停止使用MySQL。
|
||||
|
||||
首先，关闭服务：
|
||||
|
||||
```
|
||||
sudo systemctl stop mysql.service && sudo systemctl disable mysql.service
|
||||
```
|
||||
|
||||
确保你备份了你的数据库，以防你之后想使用它们。你可以通过运行下列命令卸载MySQL：
|
||||
|
||||
```
|
||||
sudo apt purge mysql*
|
||||
```
|
||||
|
||||
清理依赖：
|
||||
|
||||
```
|
||||
sudo apt autoremove
|
||||
```
|
||||
|
||||
**小结**
|
||||
|
||||
在这边文章中，我已经介绍如何在Ubuntu Linux上**安装 Mysql**。我很高兴如果这篇文章能帮助到那些正为此挣扎的用户或者刚刚开始的用户。
|
||||
In this article, I’ve covered **installing MySQL** in Ubuntu Linux. I’d be glad if this guide helps struggling users and beginners.
|
||||
|
||||
如果你发现这篇文章是一个很有用的资源，在评论里告诉我们。你为了什么使用MySQL? 我们渴望收到你的任何反馈，印象和建议。感谢阅读，并毫不犹豫地尝试这个令人难以置信的工具！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/install-mysql-ubuntu/
|
||||
|
||||
作者：[Sergiu][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[arrowfeng](https://github.com/arrowfeng)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/sergiu/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.mysql.com/
|
||||
[2]: https://en.wikipedia.org/wiki/LAMP_(software_bundle)
|
||||
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/install-mysql-ubuntu.png?resize=800%2C450&ssl=1
|
||||
[4]: https://dev.mysql.com/downloads/repo/apt/
|
||||
[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_apt_download_page.jpg?fit=800%2C280&ssl=1
|
||||
[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_deb_download_link.jpg?fit=800%2C507&ssl=1
|
||||
[7]: https://linuxhandbook.com/curl-command-examples/
|
||||
[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_package_configuration_ok.jpg?fit=800%2C587&ssl=1
|
||||
[9]: https://itsfoss.com/change-password-ubuntu/
|
||||
[10]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_enter_password.jpg?fit=800%2C583&ssl=1
|
||||
[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_information_on_configuring.jpg?fit=800%2C581&ssl=1
|
||||
[12]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_default_authentication_plugin.jpg?fit=800%2C586&ssl=1
|
||||
[13]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_service_information.jpg?fit=800%2C402&ssl=1
|
||||
[14]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/04/mysql_shell_prompt-2.jpg?fit=800%2C423&ssl=1
|
||||
@ -0,0 +1,80 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (warmfrog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (This is how System76 does open hardware)
|
||||
[#]: via: (https://opensource.com/article/19/4/system76-hardware)
|
||||
[#]: author: (Don Watkins https://opensource.com/users/don-watkins)
|
||||
|
||||
这就是 System76 如何打造开源硬件的
|
||||
================================
|
||||
是什么让新的 Thelio 台式机系列与众不同。
|
||||
![在计算机上显示度量和数据][1]
|
||||
|
||||
大多数人对他们电脑的硬件一无所知。作为一个长期的 Linux 用户，我分享了对此的失望，就是当我想让我的无线网卡，视频卡，显示器，和其他硬件与我选择的发行版共同运行时。自主品牌的硬件通常使判断这些问题变得很困难，就是：为什么以太网驱动，无线驱动，或者鼠标驱动和我们预期的不太一样？。当 Linux 分发版已经成熟，这可能不再是问题，但是我们仍能发现触控板和其他外部设备的怪异行为，尤其是当我们对下面的硬件知道的不多时。
|
||||
|
||||
像 [System76][2] 的公司目标是解决这些问题，来提升 Linux 用户体验。System76 生产了一些列的 Linux 笔记本，台式机，和服务器，甚至提供了它自己的 Linux 发行版 [Pop! OS][3] 作为客户的一个选择。最近我有幸参观了 System76 在 Devnver 的工厂并揭开 [Thelio][5] [神秘的面纱][5]，它的新的台式机产品线。
|
||||
|
||||
### 关于 Thelio
|
||||
|
||||
System76 宣称 Thelio 的开源硬件子板，被命名为木星之后的第 5 个卫星的名字 Thelio Io，这是它在市场上独特的特点之一。Thelio Io 被证实为 [OSHWA #us000145][6]，并且有 4 个用于存储的 SATA 端口和一个控制风扇和用于电源按钮控制的嵌入式控制器。Thelio IO SAS 被证实 是 [OSHWA #us000146][7]，并且有 4 个用于存储的 U.2 端口，没有嵌入式控制器。在展示时，System76 显示了这些组件如何调整风扇通过底盘来优化部件的性能。
|
||||
|
||||
该控制器还管理电源键，和围绕该电源键的 LED 光环，当被按下时它以 100% 的亮度发光。这提供了触觉和视觉上的确认：该主机已经启动电源了。当电脑在使用中，该按钮被设置为 35% 的亮度，当在睡眠模式，它的亮度在 2.35% 和 25% 之间跳动。当计算机关闭后，LED 保持朦胧的亮度，因此能够在黑暗的房间里找到电源控制。
|
||||
|
||||
Thelio 的嵌入式控制器是一个低功耗的 [ATmega32U4][8] 微控制器，并且控制器的设置可以使用 Arduino Micro 进行原型设计。Thelio Io 主板变化的多少取决于你购买哪种 Thelio 型号。
|
||||
|
||||
Thelio 可能是我见过的设计的最好的电脑样例和系统。如果你曾经亲身体验过在一个常规的 PC 的内部进行操作的话，你可能会同意我的观点。我已经做了很多次了，因此我能以自己过往的糟糕经历来证明这点。
|
||||
|
||||
### 为什么做开源硬件？
|
||||
|
||||
该主板是在 [KiCAD][9] 设计的，你可以在 [GitHub][10] 上的 GPL 证书下访问 Thelio 所有的设计文件。因此，为什么一个与其他 PC 制造商竞争的公司会设计一个独特的接口并公开授权呢？可能是该公司认识到开源设计的价值和分享的能力，并且根据你的需要调整一个 I/O 主板，即便你是市场上的竞争者。
|
||||
|
||||
![在 Thelio 启动时 Don Watkins 与 System76 的 CEO Carl Richell 谈话][11]
|
||||
|
||||
在 [Thelio 启动时][12] Don Watkins 与 System76 的 CEO Carl Richell 谈话。
|
||||
|
||||
我问 [Carl Richell][13]，System76 的设计者和 CEO，该公司是否考虑到开放它的硬件设计意味着有人采取它的独特设计并用它来将 System76 驱逐出市场。他说：
|
||||
|
||||
> 开源硬件对我们所有人都有益。这是我们未来提升技术的方式并且使得每个人获取技术更容易。我们欢迎任何想要提高 Thelio 设计的人来这么做。开源硬件不仅更快的帮助我们的电脑提升技术，并且能够使我们的消费者 100% 信任他们的设备。我们的目标是尽可能地移除专利授权，并且仍然能够为消费者提供一个有竞争力的 Linux 主机。
|
||||
>
|
||||
> 我们已经与 Linux 社区一起工作超过 13 年来为我们的笔记本，台式机，服务器创造一个完美的顺滑的体验。我们长期专注于为 Linux 社区提供服务，提供给我们的客户高水准的服务，我们的个性使 System76 变得独特。
|
||||
|
||||
我问 Carl 为什么通常来说开源硬件对 System76 和 PC 市场是有意义的。他回复道：
|
||||
|
||||
> System76 创立之初的想法是技术应该对每个人是开放和可获取的。我们还没有到达 100% 开源创造一个电脑的程度，但是有了开源硬件，我们是接近目标的必不可少的一大步。
|
||||
>
|
||||
> 我们生活在技术变成工具的时代。计算机在每一层教育和在很多工业当中是人们的工具。由于每个人特定的需要，每个人对于如何提升电脑和软件作为他们的主要工具有他们自己的想法。开源我们的计算机允许这些想法完成，反过来促进技术成为一个更强大的工具。在一个开源环境中，我们持续迭代来获取一个更好的 PC。这有点酷。
|
||||
|
||||
我们总结了我们讨论的关于 System76 技术路线的对话，包含了开源硬件 mini PC，最终还包含了笔记本。在 System76 品牌下的已售出的 mini PC 和笔记本是由其他供应商制造的，并不是基于开源硬件的（尽管他们的 Linux 软件，当然是开源的）。
|
||||
|
||||
设计和支持开放式硬件是PC业务中改变游戏规则的因素，也正是它造就了 System76 的新 Thelio 台式机电脑产品线的不同。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/system76-hardware
|
||||
|
||||
作者：[Don Watkins ][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[warmfrog](https://github.com/warmfrog)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/don-watkins
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/metrics_data_dashboard_system_computer_analytics.png?itok=oxAeIEI- (metrics and data shown on a computer screen)
|
||||
[2]: https://system76.com/
|
||||
[3]: https://opensource.com/article/18/1/behind-scenes-popos-linux
|
||||
[4]: /article/18/11/system76-thelio-desktop-computer
|
||||
[5]: https://system76.com/desktops
|
||||
[6]: https://certification.oshwa.org/us000145.html
|
||||
[7]: https://certification.oshwa.org/us000146.html
|
||||
[8]: https://www.microchip.com/wwwproducts/ATmega32u4
|
||||
[9]: http://kicad-pcb.org/
|
||||
[10]: https://github.com/system76/thelio-io
|
||||
[11]: https://opensource.com/sites/default/files/uploads/don_system76_ceo.jpg (Don Watkins speaks with System76 CEO Carl Richell at the Thelio launch event.)
|
||||
[12]: https://trevgstudios.smugmug.com/System76/121418-Thelio-Press-Event/i-FKWFxFv
|
||||
[13]: https://www.linkedin.com/in/carl-richell-9435781
|
||||
|
||||
|
||||
@ -0,0 +1,65 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (8 environment-friendly open software projects you should know)
|
||||
[#]: via: (https://opensource.com/article/19/4/environment-projects)
|
||||
[#]: author: (Laura Hilliger https://opensource.com/users/laurahilliger)
|
||||
|
||||
8 个你应该了解的环保开源项目
|
||||
======
|
||||
通过给这些致力于提升环境的项目做贡献来庆祝地球日。
|
||||
![][1]
|
||||
|
||||
在过去的几年里，我一直在帮助 [Greenpeace][2] 建立其第一个完全开源的项目，Planet 4. [Planet 4][3] 是一个全球参与平台，Greenpeace 的支持者和活动家可以互动并参与组织。它的目标是让人们代表我们的星球采取行动。我们希望邀请参与并利用人力来应对气候变化和塑料污染等全球性问题。它们正在寻找开发者、设计师、作者、贡献者和其他通过开源支持环保主义的人都非常欢迎[参与进来][4]！
|
||||
|
||||
Planet 4 远非唯一关注环境的开源项目。对于地球日，我会分享其他七个关注我们星球的开源项目。
|
||||
|
||||
**[Eco Hacker Farm][5]** 致力于支持可持续社区。它建议并支持将黑客空间/黑客基地和永续农业生活结合在一起的项目。该组织还有在线项目。访问其 [wiki][6] 或 [Twitter][7] 了解有关 Eco Hacker Farm 正在做的更多信息。
|
||||
|
||||
**[Public Lab][8]** 是一个开放社区和非营利组织，它致力于将科学掌握在公民手中。它于 2010 年在 BP 石油灾难后形成，Public Lab 与开源合作，协助环境勘探和调查。它是一个多元化的社区，有很多方法可以做[贡献][9]。
|
||||
|
||||
不久前，Opensource.com 的管理 Don Watkins 撰写了一篇 **[Open Climate Workbench][10]** 的文章，该项目来自 Apache 基金会。 [OCW][11] 提供了进行气候建模和评估的软件，可用于各种应用。
|
||||
|
||||
**[Open Source Ecology][12]** 是一个旨在改善经济运作方式的项目。该项目着眼于环境再生和社会公正，它旨在重新定义我们的一些肮脏的生产和分配技术，以创造一个更可持续的文明。
|
||||
|
||||
促进开源和大数据工具之间的合作，以实现海洋、大气、土地和气候的研究，“ **[Pangeo][13]** 是第一个推广开放、可重复和可扩展科学的社区。”大数据可以改变世界！
|
||||
|
||||
**[Leaflet][14]** 是一个著名的开源 JavaScript 库。它可以做各种各样的事情，包括环保项目，如 [Arctic Web Map][15]，它能让科学家准确地可视化和分析北极地区，这是气候研究的关键能力。
|
||||
|
||||
当然，没有我在 Mozilla 的朋友就没有这个列表（不是这个完整的列表！）。**[Mozilla Science Lab][16]** 社区就像所有 Mozilla 项目一样，非常开放，它致力于将开源原则带给科学界。它的项目和社区使科学家能够进行我们世界所需的各种研究，以解决一些最普遍的环境问题。
|
||||
|
||||
### 如何贡献
|
||||
|
||||
在这个地球日，做为期六个月的承诺，将一些时间贡献给一个有助于应对气候变化的开源项目，或以其他方式鼓励人们保护地球母亲。肯定还有许多关注环境的开源项目，所以请在评论中留言！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/environment-projects
|
||||
|
||||
作者：[Laura Hilliger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/laurahilliger
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/world_hands_diversity.png?itok=zm4EDxgE
|
||||
[2]: http://www.greenpeace.org
|
||||
[3]: http://medium.com/planet4
|
||||
[4]: https://planet4.greenpeace.org/community/#partners-open-sourcers
|
||||
[5]: https://wiki.ecohackerfarm.org/start
|
||||
[6]: https://wiki.ecohackerfarm.org/
|
||||
[7]: https://twitter.com/EcoHackerFarm
|
||||
[8]: https://publiclab.org/
|
||||
[9]: https://publiclab.org/contribute
|
||||
[10]: https://opensource.com/article/17/1/apache-open-climate-workbench
|
||||
[11]: https://climate.apache.org/
|
||||
[12]: https://wiki.opensourceecology.org/wiki/Project_needs
|
||||
[13]: http://pangeo.io/
|
||||
[14]: https://leafletjs.com/
|
||||
[15]: https://webmap.arcticconnect.ca/#ac_3573/2/20.8/-65.5
|
||||
[16]: https://science.mozilla.org/
|
||||
@ -0,0 +1,97 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Tracking the weather with Python and Prometheus)
|
||||
[#]: via: (https://opensource.com/article/19/4/weather-python-prometheus)
|
||||
[#]: author: (Moshe Zadka https://opensource.com/users/moshez)
|
||||
|
||||
使用 Python 和 Prometheus 跟踪天气
|
||||
======
|
||||
创建自定义 Prometheus 集成以跟踪最大的云提供者：地球母亲。
|
||||
![Tree clouds][1]
|
||||
|
||||
开源监控系统 [Prometheus][2] 有跟踪多种类型的时间序列数据的集成，但如果不存在你想要的集成，那么很容易构建一个。一个经常使用的例子使用云提供商的自定义集成，它使用提供商的 API 抓取特定的指标。但是，在这个例子中，我们将与最大云提供商集成：地球。
|
||||
|
||||
幸运的是，美国政府已经测量了天气并为集成提供了一个简单的 API。获取红帽总部下一个小时的天气预报很简单。
|
||||
|
||||
|
||||
```
|
||||
import requests
|
||||
HOURLY_RED_HAT = "<https://api.weather.gov/gridpoints/RAH/73,57/forecast/hourly>"
|
||||
def get_temperature():
|
||||
result = requests.get(HOURLY_RED_HAT)
|
||||
return result.json()["properties"]["periods"][0]["temperature"]
|
||||
```
|
||||
|
||||
现在我们已经完成了与地球的整合，现在是确保 Prometheus 能够理解我们想要内容的时候了。我们可以使用 [Prometheus Python 库][3]中的 _gauge_ 创建一个注册：红帽总部的温度。
|
||||
|
||||
|
||||
```
|
||||
from prometheus_client import CollectorRegistry, Gauge
|
||||
def prometheus_temperature(num):
|
||||
registry = CollectorRegistry()
|
||||
g = Gauge("red_hat_temp", "Temperature at Red Hat HQ", registry=registry)
|
||||
g.set(num)
|
||||
return registry
|
||||
```
|
||||
|
||||
最后，我们需要以某种方式将它连接到 Prometheus。这有点依赖 Prometheus 的网络拓扑：Prometheus 与我们的服务通信更容易，还是反向更容易。
|
||||
|
||||
第一种是通常建议的情况，如果可能的话，我们需要构建一个公开注册入口的 Web 服务器，并配置 Prometheus _收刮_（scrape）它。
|
||||
|
||||
我们可以使用 [Pyramid][4] 构建一个简单的 Web 服务器。
|
||||
|
||||
|
||||
```
|
||||
from pyramid.config import Configurator
|
||||
from pyramid.response import Response
|
||||
from prometheus_client import generate_latest, CONTENT_TYPE_LATEST
|
||||
def metrics_web(request):
|
||||
registry = prometheus_temperature(get_temperature())
|
||||
return Response(generate_latest(registry),
|
||||
content_type=CONTENT_TYPE_LATEST)
|
||||
config = Configurator()
|
||||
config.add_route('metrics', '/metrics')
|
||||
config.add_view(metrics_web, route_name='metrics')
|
||||
app = config.make_wsgi_app()
|
||||
```
|
||||
|
||||
这可以使用任何 Web 网关接口 （WSGI） 服务器运行。例如，假设我们将代码放在 **earth.py** 中，我们可以使用 **python -m twisted web --wsgi earth.app** 来运行它。
|
||||
|
||||
或者，如果我们的代码连接到 Prometheus 更容易，我们可以定期将其推送到 Prometheus 的[推送网关][5]。
|
||||
|
||||
|
||||
```
|
||||
import time
|
||||
from prometheus_client import push_to_gateway
|
||||
def push_temperature(url):
|
||||
while True:
|
||||
registry = prometheus_temperature(get_temperature())
|
||||
push_to_gateway(url, "temperature collector", registry)
|
||||
time.sleep(60*60)
|
||||
```
|
||||
|
||||
URL 是推送网关的 URL。它通常以 **:9091** 结尾。
|
||||
|
||||
祝你构建自定义 Prometheus 集成成功，以便跟踪一切！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/4/weather-python-prometheus
|
||||
|
||||
作者：[Moshe Zadka ][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/moshez
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life_tree_clouds.png?itok=b_ftihhP (Tree clouds)
|
||||
[2]: https://prometheus.io/
|
||||
[3]: https://github.com/prometheus/client_python
|
||||
[4]: https://trypyramid.com/
|
||||
[5]: https://github.com/prometheus/pushgateway
|
||||
Some files were not shown because too many files have changed in this diff Show More
Loading…
Reference in New Issue
Block a user