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5367be367e
@ -23,7 +23,7 @@ Linux有问必答：如何检查Linux系统的最后重启时间
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### 方法三 ###
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你同样可以使用uptime命令来推断系统最后的启动时间。uptime命令会显示当前的时间，同样也会显示系统已经运行的时间。从这些信息中，你就可以计算系统最后启动的时间了
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你同样可以使用uptime命令来推断系统最后的启动时间。uptime命令会显示当前的时间，同样也会显示系统已经运行的时间。从这些信息中，你就可以计算系统最后启动的时间了
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$ uptime
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@ -1,13 +1,11 @@
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(translated by szrlee)
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真的超赞！用systemd命令来管理linux系统！
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================================================================================
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Systemd是一种新的linux系统服务管理器。
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它替换了init系统，能够管理系统的启动过程和一些系统服务，一旦启动起来，就将监管整个系统。在本文中，我们用的是[centos 7.0 installed with systemd 216 version][1]和最新版本[available for download from freedesktop.org][2]。
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它替换了init系统，能够管理系统的启动过程和一些系统服务，一旦启动起来，就将监管整个系统。在本文中，我们用的是[安装有 systemd 216 版本的centos 7.0][1]，其最新版本[可以从 freedesktop.org 下载得到][2]。
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因为linux系统里这一新的玩家，PID 1被“systemd”占据了，这能通过**pstree**命令看到。
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因为linux操作系统里出现的这一个新人，PID 1被“systemd”占据了，这能通过**pstree**命令看到。
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[root@linoxide ~]# pstree
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@ -15,25 +13,25 @@ Systemd是一种新的linux系统服务管理器。
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那么现在让我们来探索systemd擅长什么，它又有多大的可能性成为sysVinit的新的替代品。
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### 1. Faster startup ###
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### 1. 更快启动 ###
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sysvinit一次一个串行地启动进程。
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而Systemd则并行地启动系统服务进程，并且最初仅启动确实被依赖的那些服务，极大地减少了系统引导的时间。
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你可以用下面的命令看到系统引导的过程：
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你可以用下面的命令看到系统引导用时：
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[root@linoxide ~]# systemd-analyze
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**systemd-analyze time**也能够显示同样的内容。
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使用 **time** 参数也能够显示同样的内容。
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[root@linoxide ~]# systemd-analyze time
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如果你想以初始化时间排序打印出所有正在运行unit的列表，那么**systemd-analyze**命令可以帮助你完成这个任务。
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如果你想以进程初始化所占用时间排序打印出所有正在运行的单元列表，那么**systemd-analyze**命令可以帮助你完成这个任务。
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[root@linoxide ~]# systemd-analyze blame
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@ -41,25 +39,25 @@ sysvinit一次一个串行地启动进程。
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上面的截屏只显示了小部分进程，你可以就像less分页器那样用箭头滚动列表。
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### 2. The systemctl command ###
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### 2. systemctl 命令 ###
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systemctl命令是自systemd出现以来被广泛讨论的命令。你可以通过这个命令管理你的整个系统，让我们通过探究这个命令来更进一步。
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#### 2.1 List Units ####
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#### 2.1 列出单元 ####
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**systemctl**命令可以带上list-units也可以什么选项都不带来列出所有正在运行的unit。
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**systemctl**命令可以带上list-units，也可以什么选项都不带来列出所有正在运行的单元。
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[root@linoxide ~]# systemctl
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or
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或
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[root@linoxide ~]# systemctl list-units
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#### 2.2 Listing failed units ####
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#### 2.2 列出失败的单元 ####
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运行失败的unit可以用带--failed选项的命令显示出来。
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运行失败的单元可以用带--failed选项的命令显示出来。
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[root@linoxide ~]# systemctl --failed
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@ -67,11 +65,11 @@ or
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你可以在这篇文章很多地方看到systemctl的用法。
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### 3. Managing services ###
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### 3. 管理服务 ###
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让我们来看看systemd是怎么管理系统服务的。
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#### 3.1 Active services ####
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#### 3.1 激活的服务 ####
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所有被激活的服务可以同下面这条命令来查看。
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@ -79,7 +77,7 @@ or
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#### 3.2 Service status ####
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#### 3.2 服务状态 ####
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在sysvinit中，我们可以用“**service**”命令来管理服务，但在systemd中，我们用systemctl这个命令。
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我们可以用下面这个命令来查看服务是否在运行。
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@ -88,17 +86,17 @@ or
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#### 3.3 Start a service ####
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#### 3.3 启动一个服务 ####
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用下面这条命令来启动服务。
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[root@linoxide ~]# systemctl start dnsmasq
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相对于**service**服务，这个命令不进行输出。但是毋庸置疑，我们可以通过再次查看这个刚刚被启动的服务的status（状态）来确认他是否被成功地启动了。
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对应于**service**命令，这个命令不进行输出。但是毋庸置疑，我们可以通过再次查看这个刚刚被启动的服务的status（状态）来确认他是否被成功地启动了。
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#### 3.4 Stopping a service ####
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#### 3.4 停止一个服务 ####
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现在聪明的你一定知道怎么在systemd下用命令来关闭服务了吧。
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@ -106,7 +104,7 @@ or
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#### 3.5 Restart a service ####
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#### 3.5 重启一个服务 ####
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类似的，重启系统服务是用‘**systemctl restart**’来管理的。
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@ -114,7 +112,7 @@ or
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#### 3.6 Reload a service ####
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#### 3.6 重新加载一个服务 ####
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在我们需要重新加载服务的配置文件又不想重启这个服务（例如ssh）时，我们可以用这个命令。
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@ -122,17 +120,17 @@ or
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虽然上述命令的语法是可以工作的，但是官方文档建议我们用下面这种语法形式来运行命令：
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虽然上述几个命令的语法是可以工作的，但是官方文档建议我们用下面这种语法形式来运行命令（LCTT 译注，即使用在服务名后面跟上“.service”的完整名称）：
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[root@linoxide ~]# systemctl status dnsmasq.service
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### 4. Managing services at boot ###
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### 4. 管理引导时的服务 ###
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**chkconfig**命令被用来管理系统引导时的服务。同样用systemd也可以管理boot时的系统服务。
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**chkconfig**命令被用来管理系统引导时的服务。同样用systemd也可以管理引导时的系统服务。
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#### 4.1 Checking service status at boot ####
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#### 4.1 检查服务引导时是否运行 ####
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这条命令用来确定服务是否是引导时启动的。
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@ -140,7 +138,7 @@ or
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#### 4.2 Enable a service at boot ####
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#### 4.2 让服务在引导时运行 ####
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**systemctl**命令是这样来enable（使之在引导时启动）一个服务的。（这相当于sysvinit中的‘**chkconfig on**’）
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@ -148,7 +146,7 @@ or
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#### 4.3 Disable a service at boot ####
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#### 4.3 取消服务在引导时运行 ####
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类似的，使服务不在引导时启动用这个命令。
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@ -156,18 +154,18 @@ or
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### 5. Managing Remote systems ###
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### 5. 管理远程系统 ###
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所有刚才提到的systemctl命令通常都能被用来管理远程主机，完成这个任务将用到**ssh**来进行通讯。你只需要像这样将远程主机和用户名
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添加到systemctl命令后。
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所有刚才提到的systemctl命令通常都能被用来管理远程主机，完成这个任务将用到**ssh**来进行通讯。你只需要像这样将远程主机和用户名添加到systemctl命令后。
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[root@linoxide ~]# systemctl status sshd -H root@1.2.3.4
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### 6. Managing targets: ###
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### 6. 管理目标 ###
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Systemd有一个完成与sysVinit的runlevels相似任务的构想。
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sysVinit的runlevels大多是以数字分级的。这里是runlevers在systemd中的对应元素。
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> 0 runlevel0.target, poweroff.target
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@ -184,7 +182,7 @@ sysVinit的runlevels大多是以数字分级的。这里是runlevers在systemd
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>
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> emergency emergency.target
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#### 6.1 Changing current target ####
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#### 6.1 改变当前目标 ####
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当前target可以用这个命令切换。
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@ -192,39 +190,38 @@ sysVinit的runlevels大多是以数字分级的。这里是runlevers在systemd
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#### 6.2 List current target ####
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#### 6.2 列出当前目标 ####
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如果你想查看你正处于哪个target中，你需要列出相应的units。虽然这样操作可能让你不太爽，但是这就是systemd工作的方式。
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如果你想查看你正处于哪个target中，你需要列出相应的单元。虽然这样操作可能让你不太爽，但是这就是systemd工作的方式。
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[root@linoxide ~]# systemctl list-units --type=target
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你可以看到“graphical.target”列在此处，这就是我们刚才切换到的target。现在，让我们切换runlever到multi-user.target然后分析下列命令的输出。
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你可以看到“graphical.target”列在此处，这就是我们刚才切换到的目标。现在，让我们切换runlevel到multi-user.target，然后分析下列命令的输出。
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[root@linoxide ~]# systemctl isolate multi-user.target
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[root@linoxide ~]# systemctl list-units --type=target
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#### 6.3 List default target ####
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#### 6.3 列出默认目标 ####
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用这个systemctl命令来查看默认target。
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用这个systemctl命令来查看默认目标。
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[root@linoxide ~]# systemctl get-default
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#### 6.4 Change default target ####
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#### 6.4 改变默认目标 ####
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通过systemctl的set-default命令可以将某个target设置成默认target。
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通过systemctl的set-default命令可以将某个目标设置成默认目标。
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[root@linoxide ~]# systemctl set-default graphical.target
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### 7. Logging in systemd ###
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### 7. 记录 systemd 的日志 ###
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journald是systemd独有的日志系统，替换了sysVinit中的syslog守护进程。命令**journalctl**用来读取日志。
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@ -232,7 +229,7 @@ journald是systemd独有的日志系统，替换了sysVinit中的syslog守护进
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#### 7.1 Boot messages ####
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#### 7.1 查看引导信息 ####
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运行**journalctl -b**命令来查看所有引导日志。
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@ -240,16 +237,15 @@ journald是systemd独有的日志系统，替换了sysVinit中的syslog守护进
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#### 7.2 Follow logs ####
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#### 7.2 即时显示引导日志 ####
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下面这个命令可以即时显示系统日志（类似**tail -f**）。
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下面这个命令可以实时显示系统日志（类似**tail -f**）。
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[root@linoxide ~]# journalctl -f
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#### 7.3 Service specific logs ####
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#### 7.3 查看特定服务的日志 ####
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你可以像这样运用**journalctl**来查看你只想看到的服务或可执行程序的日志。
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@ -257,11 +253,11 @@ journald是systemd独有的日志系统，替换了sysVinit中的syslog守护进
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### 8. Power management ###
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### 8. 电源管理 ###
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systemctl命令也可以用来关机，重启或者休眠。
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To poweroff, reboot, suspend and hibernate, use the following commands respectively:
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要关机、重启、挂起和休眠，分别使用如下命令：
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[root@linoxide ~]# systemctl poweroff
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@ -271,7 +267,7 @@ To poweroff, reboot, suspend and hibernate, use the following commands respectiv
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[root@linoxide ~]# systemctl hibernate
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### 9. Bonus ###
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### 9. 又及 ###
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**systemd**带来了一整套与操作系统交互的新途径，并且极具特色。举个栗子，你可以用hostnamectl命令来获得你的linux机器的hostname和其它有用的独特信息。
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@ -285,7 +281,7 @@ via: http://linoxide.com/linux-command/linux-systemd-commands/
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作者：[Raghu][a]
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译者：[szrlee](https://github.com/szrlee)
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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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
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@ -0,0 +1,38 @@
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||||
How to Go Hands On With the Utopic Unicorn – Literally!
|
||||
================================================================================
|
||||
**Looking to go hands-on with the Utopic Unicorn ahead of its release? Now you can — [literally][1]!**
|
||||
|
||||
A step-by-step guide to making your own paper Unicorn (to celebrate the upcoming release of the same name, obviously) has been posted online by Canonical. The instructions were offered as part of the company’s presence at the 2014 [deconstruct][2] event held in Brighton, UK in early September.
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|
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|
||||
|
||||
Image: Alejandra Obregon
|
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|
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The one-day conference for creative professionals and digital culture enthusiasts served as an ideal place for Canonical to showcase an in-progress version of the upcoming Ubuntu Phone, its design and the user interaction benefits they believe it offers.
|
||||
|
||||
Reaction was positive, they say. That will have made the prize of a brand new Ubuntu phone to the maker of the best origami unicorn all the more tempting!
|
||||
|
||||
### Download Origami Unicorn ###
|
||||
|
||||
No prizes are on offer to the rest of us attempting to fold our way to frustration, but a download of the how-to is.
|
||||
|
||||
If you have a spare five hours minutes, why not make one for fun? If you make particularly epic success/fail of it be sure to send us a pic on [Twitter][3] or [Google+][4].
|
||||
|
||||
- [Download ‘Make a Unicorn’ Instructions][5]
|
||||
|
||||
--------------------------------------------------------------------------------
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|
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via: http://www.omgubuntu.co.uk/2014/09/unicorn-origami-download-pdf-ubuntu-utopic
|
||||
|
||||
作者：[Joey-Elijah Sneddon][a]
|
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译者：[译者ID](https://github.com/译者ID)
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||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
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[a]:https://plus.google.com/117485690627814051450/?rel=author
|
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[1]:http://design.canonical.com/2014/09/canonical-and-ubuntu-at-dconstruct/
|
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[2]:http://2014.dconstruct.org/
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[3]:http://twitter.com/omgubuntu
|
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[4]:http://plus.google.com/+omgubuntu
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[5]:http://design.canonical.com/wp-content/uploads/042_CAN_dConstruct_instructions.pdf
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@ -1,75 +0,0 @@
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[su-kaiyao]翻译中
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|
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With Apple Watch Unveiled, Could an Ubuntu Smartwatch Be Next?
|
||||
================================================================================
|
||||
**Apple today confirmed its long-rumoured foray into the wearable computing market with the launch of ‘Apple Watch’.**
|
||||
|
||||
|
||||
|
||||
Ubuntu Smartwatch – good idea?
|
||||
|
||||
Backed by a robust set of features, hardware solutions and app partnerships, the wrist mounted device is being heralded by the company as “a new chapter in the relationship people have with technology.”
|
||||
|
||||
But does its arrival, and the uptick in consumer interest it will likely bring, mean Ubuntu should follow with a version of Ubuntu for smartwatches?
|
||||
|
||||
### Big Hand Is On Success ###
|
||||
|
||||
Apple joins the fast growing smart-watch sector at just about the right time. The boundaries of what a wrist-mounted computer can and should do are not yet set in stone. Bad design, poor user interfaces, and weak arguments for the usefulness of wearable technology to mainstream users has seen the hardware category remains sufficiently impressionable — a factor that has allowed Cupertino to take its time with the Apple Watch.
|
||||
|
||||
> ‘More than 22 million smartwatches will be sold this year, say analysts’
|
||||
|
||||
Sales of wearables, including fitness trackers, last year were just shy of 10 million units worldwide. This year the number of devices analysts expect to see shifted will pass 22 million — and that’s without the Apple Watch, which doesn’t hit retail until early 2015.
|
||||
|
||||
It’s easy to see where the growth is going to come from. The IFA 2014 tradeshow held in Berlin at the start of September played host to a swathe of new wearables from major OEMs, including Sony and ASUS. Most are running Google’s newly released Android Wear platform.
|
||||
|
||||
A more mature offering, Android Wear debunks the novelty argument often associated with the form factor to present a consistent and convincing user scenario. Though, as with the new Apple Watch, it is one tightly hinging on an existing smartphone ecosystem.
|
||||
|
||||
Whether it’s a use case a wrist-mounted version Ubuntu can match isn’t (yet) clear.
|
||||
|
||||
#### ‘No Plans for an Ubuntu Smartwatch’ ####
|
||||
|
||||
The versatility of the Ubuntu OS combined with the stringent vision for a multi-device and convergent future has already seen Canonical target smart TVs, tablets and smartphones. Mir, the company’s homegrown display server, was even created to power interfaces on screens of all sizes (though admittedly not 1.5″ ones!).
|
||||
|
||||
At the start of this year then-Canonical community manager Jono Bacon was asked whether there were plans for an Ubuntu watch. Offering his opinion on the subject, Bacon mused: “adding another form factor to the [ubuntu touch] roadmap would only slow things down”.
|
||||
|
||||
As the two year anniversary of the Ubuntu Phone announcement approaches, it’s hard not to agree with him.
|
||||
|
||||
### Tick, Tock, Hedge-Your-Bets O’Clock ###
|
||||
|
||||
But all hope is not lost. In a [press call a few months later][1] Ubuntu founder Mark Shuttleworth mentioned wearable technologies in the same breath as the company’s plans for TVs, tablets and smartphones, saying:
|
||||
|
||||
> “Ubuntu is really unique in that it has this beautiful design on the phone, but it’s also designed at the same time to feed all of those other ecosystems, from wearables to the PC.”
|
||||
|
||||
While far from concrete confirmation, it serves as a pointer; an optimistic hedge in that direction.
|
||||
|
||||
#### Not likely — and here’s why ####
|
||||
|
||||
Canonical is not averse to entering markets with entrenched monopolies. In fact, it’s in the DNA of the company — RHEL on servers, Windows on desktops, Android on smartphones…
|
||||
|
||||
Ubuntu for devices is built as such that it could be expended to and adapted to run on smaller screens, possible even those as small as a watch face. When the common code base is in place for phone, tablet, desktop and TV I’d be surprised if we didn’t see some sort of effort in this direction from the community.
|
||||
|
||||
But reason why I don’t think it’s likely to happen from Canonical’s side, at least not yet, is an echo of Jono Bacon’s personal thoughts earlier this year: time and effort.
|
||||
|
||||
Tim Cook said in his keynote: “*We didn’t take the iPhone and shrink the user interface and strap it on your wrist.*” It’s an obvious statement. Designing a UI and UX model for such a small screen; working through interaction methodologies; complimenting hardware and input models isn’t a simple task.
|
||||
|
||||
Wearable technology is still a nascent market. At this stage Canonical would be wasting development, design and business time in pursuing it. Any benefits would be outweighed by the loss in other, more pressing areas.
|
||||
|
||||
Playing the longer game, waiting it out to see where other efforts succeed and fail, is the harder route, but the one better suited to Ubuntu as it stands today. It’s better for Canonical to focus energies on existing products (which some argue are already arriving late) before throwing newer ones out ahead of them.
|
||||
|
||||
**For an idea of what an Ubuntu smartwatch could be like hit play on the following video which shows an interactive Unity themed skin for the Tizen powered Samsung Galaxy Gear smartwatch.**
|
||||
|
||||
注：youtube视频，发布的时候不行做个链接吧
|
||||
<iframe width="750" height="563" frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/8Zf5dktXzEs?feature=oembed"></iframe>
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.omgubuntu.co.uk/2014/09/ubuntu-smartwatch-apple-iwatch
|
||||
|
||||
作者：[Joey-Elijah Sneddon][a]
|
||||
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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://plus.google.com/117485690627814051450/?rel=author
|
||||
[1]:http://www.omgubuntu.co.uk/2014/03/ubuntu-tablets-coming-year
|
||||
@ -0,0 +1,86 @@
|
||||
What’s wrong with IPv4 and Why we are moving to IPv6
|
||||
================================================================================
|
||||
For the past 10 years or so, this has been the year that IPv6 will become wide spread. It hasn’t happened yet. Consequently, there is little widespread knowledge of what IPv6 is, how to use it, or why it is inevitable.
|
||||
|
||||
|
||||
|
||||
IPv4 and IPv6 Comparison
|
||||
|
||||
### What’s wrong with IPv4? ###
|
||||
|
||||
We’ve been using **IPv4** ever since RFC 791 was published in 1981. At the time, computers were big, expensive, and rare. IPv4 had provision for **4 billion IP** addresses, which seemed like an enormous number compared to the number of computers. Unfortunately, IP addresses are not use consequently. There are gaps in the addressing. For example, a company might have an address space of **254 (2^8-2)** addresses, and only use 25 of them. The remaining 229 are reserved for future expansion. Those addresses cannot be used by anybody else, because of the way networks route traffic. Consequently, what seemed like a large number in 1981 is actually a small number in 2014.
|
||||
|
||||
The Internet Engineering Task Force (**IETF**) recognized this problem in the early 1990s and came up with two solutions: Classless Internet Domain Router (**CIDR**) and private IP addresses. Prior to the invention of CIDR, you could get one of three network sizes: **24 bits** (16,777,214 addresses), **20 bits** (1,048,574 addresses) and **16 bits** (65,534 addresses). Once CIDR was invented, it was possible to split networks into subnetworks.
|
||||
|
||||
So, for example, if you needed **5 IP** addresses, your ISP would give you a network with a size of 3 bits which would give you **6 IP** addresses. So that would allow your ISP to use addresses more efficiently. Private IP addresses allow you to create a network where each machine on the network can easily connect to another machine on the internet, but where it is very difficult for a machine on the internet to connect back to your machine. Your network is private, hidden. Your network could be very large, 16,777,214 addresses, and you could subnet your private network into smaller networks, so that you could manage your own addresses easily.
|
||||
|
||||
You are probably using a private address right now. Check your own IP address: if it is in the range of **10.0.0.0 – 10.255.255.255** or **172.16.0.0 – 172.31.255.255** or **192.168.0.0 – 192.168.255.255**, then you are using a private IP address. These two solutions helped forestall disaster, but they were stopgap measures and now the time of reckoning is upon us.
|
||||
|
||||
Another problem with **IPv4** is that the IPv4 header was variable length. That was acceptable when routing was done by software. But now routers are built with hardware, and processing the variable length headers in hardware is hard. The large routers that allow packets to go all over the world are having problems coping with the load. Clearly, a new scheme was needed with fixed length headers.
|
||||
|
||||
Still another problem with **IPv4** is that, when the addresses were allocated, the internet was an American invention. IP addresses for the rest of the world are fragmented. A scheme was needed to allow addresses to be aggregated somewhat by geography so that the routing tables could be made smaller.
|
||||
|
||||
Yet another problem with IPv4, and this may sound surprising, is that it is hard to configure, and hard to change. This might not be apparent to you, because your router takes care of all of these details for you. But the problems for your ISP drives them nuts.
|
||||
|
||||
All of these problems went into the consideration of the next version of the Internet.
|
||||
|
||||
### About IPv6 and its Features ###
|
||||
|
||||
The **IETF** unveiled the next generation of IP in December 1995. The new version was called IPv6 because the number 5 had been allocated to something else by mistake. Some of the features of IPv6 included.
|
||||
|
||||
- 128 bit addresses (3.402823669×10³⁸ addresses)
|
||||
- A scheme for logically aggregating addresses
|
||||
- Fixed length headers
|
||||
- A protocol for automatically configuring and reconfiguring your network.
|
||||
|
||||
Let’s look at these features one by one:
|
||||
|
||||
#### Addresses ####
|
||||
|
||||
The first thing everybody notices about **IPv6** is that the number of addresses is enormous. Why so many? The answer is that the designers were concerned about the inefficient organization of addresses, so there are so many available addresses that we could allocate inefficiently in order to achieve other goals. So, if you want to build your own IPv6 network, chances are that your ISP will give you a network of **64 bits** (1.844674407×10¹⁹ addresses) and let you subnet that space to your heart’s content.
|
||||
|
||||
#### Aggregation ####
|
||||
|
||||
With so many addresses to use, the address space can be allocated sparsely in order to route packets efficiently. So, your ISP gets a network space of **80 bits**. Of those 80 bits, 16 of them are for the ISPs subnetworks, and 64 bits are for the customer’s networks. So, the ISP can have 65,534 networks.
|
||||
|
||||
However, that address allocation isn’t cast in stone, and if the ISP wants more smaller networks, it can do that (although probably the ISP would probably simply ask for another space of 80 bits). The upper 48 bits is further divided, so that ISPs that are “**close**” to one another have similar network addresses ranges, to allow the networks to be aggregated in the routing tables.
|
||||
|
||||
#### Fixed length Headers ####
|
||||
|
||||
An **IPv4** header has a variable length. An **IPv6** header always has a fixed length of 40 bytes. In IPv4, extra options caused the header to increase in size. In IPv6, if additional information is needed, that additional information is stored in extension headers, which follow the IPv6 header and are generally not processed by the routers, but rather by the software at the destination.
|
||||
|
||||
One of the fields in the IPv6 header is the flow. A flow is a **20 bit** number which is created pseudo-randomly, and it makes it easier for the routers to route packets. If a packet has a flow, then the router can use that flow number as an index into a table, which is fast, rather than a table lookup, which is slow. This feature makes **IPv6** very easy to route.
|
||||
|
||||
#### Automatic Configuration ####
|
||||
|
||||
In **IPv6**, when a machine first starts up, it checks the local network to see if any other machine is using its address. If the address is unused, then the machine next looks for an IPv6 router on the local network. If it finds the router, then it asks the router for an IPv6 address to use. Now, the machine is set and ready to communicate on the internet – it has an IP address for itself and it has a default router.
|
||||
|
||||
If the router should go down, then the machines on the network will detect the problem and repeat the process of looking for an IPv6 router, to find the backup router. That’s actually hard to do in IPv4. Similarly, if the router wants to change the addressing scheme on its network, it can. The machines will query the router from time to time and change their addresses automatically. The router will support both the old and new addresses until all of the machines have switched over to the new configuration.
|
||||
|
||||
IPv6 automatic configuration is not a complete solution. There are some other things that a machine needs in order to use the internet effectively: the name servers, a time server, perhaps a file server. So there is **dhcp6** which does the same thing as dhcp, only because the machine boots in a routable state, one dhcp daemon can service a large number of networks.
|
||||
|
||||
#### There’s one big problem ####
|
||||
|
||||
So if IPv6 is so much better than IPv4, why hasn’t adoption been more widespread (as of **May 2014**, Google estimates that its IPv6 traffic is about **4%** of its total traffic)? The basic problem is which comes first, the **chicken or the egg**? Somebody running a server wants the server to be as widely available as possible, which means it must have an **IPv4** address.
|
||||
|
||||
It could also have an IPv6 address, but few people would use it and you do have to change your software a little to accommodate IPv6. Furthermore, a lot of home networking routers do not support IPv6. A lot of ISPs do not support IPv6. I asked my ISP about it, and I was told that they will provide it when customers ask for it. So I asked how many customers had asked for it. One, including me.
|
||||
|
||||
By way of contrast, all of the major operating systems, Windows, OS X, and Linux support IPv6 “**out of the box**” and have for years. The operating systems even have software that will allow IPv6 packets to “**tunnel**” within IPv4 to a point where the IPv6 packets can be removed from the surrounding IPv4 packet and sent on their way.
|
||||
|
||||
#### Conclusion ####
|
||||
|
||||
IPv4 has served us well for a long time. IPv4 has some limitations which are going to present insurmountable problems in the near future. IPv6 will solve those problems by changing the strategy for allocating addresses, making improvements to ease the routing of packets, and making it easier to configure a machine when it first joins the network.
|
||||
|
||||
However, acceptance and usage of IPv6 has been slow, because change is hard and expensive. The good news is that all operating systems support IPv6, so when you are ready to make the change, your computer will need little effort to convert to the new scheme.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/ipv4-and-ipv6-comparison/
|
||||
|
||||
作者：[Jeff Silverman][a]
|
||||
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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/jeffsilverm/
|
||||
@ -1,3 +1,4 @@
|
||||
Translating by ZTinoZ
|
||||
10 Useful “Squid Proxy Server” Interview Questions and Answers in Linux
|
||||
================================================================================
|
||||
It’s not only to System Administrator and Network Administrator, who listens the phrase Proxy Server every now and then but we too. Proxy Server is now a corporate culture and is the need of the hour. Proxy server now a days is implemented from small schools, cafeteria to large MNCs. Squid (also known as proxy) is such an application which acts as proxy server and one of the most widely used tool of its kind.
|
||||
@ -128,4 +129,4 @@ via: http://www.tecmint.com/squid-interview-questions/
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/avishek/
|
||||
[a]:http://www.tecmint.com/author/avishek/
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
johnhoow translating...
|
||||
Use LaTeX In Ubuntu 14.04 and Linux Mint 17 With Texmaker
|
||||
================================================================================
|
||||
|
||||
@ -42,4 +43,4 @@ via: http://itsfoss.com/install-latex-ubuntu-1404/
|
||||
[1]:http://www.latex-project.org/
|
||||
[2]:http://www.xm1math.net/texmaker/index.html
|
||||
[3]:http://www.xm1math.net/texmaker/download.html#linux
|
||||
[4]:http://itsfoss.com/remarkable-markdown-editor-linux/
|
||||
[4]:http://itsfoss.com/remarkable-markdown-editor-linux/
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
johnhoow translating...
|
||||
Install UberWriter Markdown Editor In Ubuntu 14.04
|
||||
================================================================================
|
||||
Quick tutorial to show you **how to install UberWriter markdown editor in Ubuntu 14.04** for free via official PPA.
|
||||
@ -57,4 +58,4 @@ via: http://itsfoss.com/install-uberwriter-markdown-editor-ubuntu-1404/
|
||||
[3]:http://johnmacfarlane.net/pandoc/
|
||||
[4]:apt://uberwriter
|
||||
[5]:http://itsfoss.com/remarkable-markdown-editor-linux/
|
||||
[6]:http://itsfoss.com/install-latex-ubuntu-1404/
|
||||
[6]:http://itsfoss.com/install-latex-ubuntu-1404/
|
||||
|
||||
@ -0,0 +1,53 @@
|
||||
QuiteRSS: RSS Reader For Desktop Linux
|
||||
================================================================================
|
||||
[QuiteRSS][1] is a free and [open source][2] RSS/Atome reader available for Windows , Linux and Mac. Written in C++/QT, it comes with a number of features.
|
||||
|
||||
The interface of QuiteRSS reminds me of Lotus Notes mail. You have plenty of RSS displayed in right side pane, which you can group together in labels. Clicking on an item, opens the RSS feed in lower panel.
|
||||
|
||||
|
||||
|
||||
Apart from this, it has ad blocker, a newspaper layout view, importing feeds from URL features etc. You can find the full list of features [here][3].
|
||||
|
||||
### Install QuiteRSS in Ubuntu and Linux Mint ###
|
||||
|
||||
QuiteRSS is available in Ubuntu 14.04 and Linux Mint 17. You can install it by simply using the command below:
|
||||
|
||||
sudo apt-get install quiterss
|
||||
|
||||
If you want to have the latest stable version, you can use the official [QuiteRSS PPA][4]:
|
||||
|
||||
sudo add-apt-repository ppa:quiterss/quiterss
|
||||
sudo apt-get update
|
||||
sudo apt-get install quiterss
|
||||
|
||||
The above should work for all Ubuntu based Linux distributions such as Linux Mint, Elementary OS, Linux Lite, Pinguy OS etc. For other Linux distributions and other platforms, you can get the source code and installers from the [download page][5].
|
||||
|
||||
### Uninstall QuiteRSS ###
|
||||
|
||||
To uninstall QuiteRSS, use the following command:
|
||||
|
||||
sudo apt-get remove quiterss
|
||||
|
||||
If you used the PPA, you should also remove the repository from the sources list.
|
||||
|
||||
sudo add-apt-repository --remove ppa:quiterss/quiterss
|
||||
|
||||
QuiteRSS is a fine Open Source RSS reader, though I prefer [Feedly][6]. Though there is no desktop application of Feedly for Linux as of now, you can still use it in web browser apart from your smartphone. I hope you find QuiteRSS worth a try on desktop Linux.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://itsfoss.com/quiterss-rss-reader-desktop-linux/
|
||||
|
||||
作者：[Abhishek][a]
|
||||
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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://itsfoss.com/author/Abhishek/
|
||||
[1]:http://quiterss.org/
|
||||
[2]:http://itsfoss.com/category/open-source-software/
|
||||
[3]:http://quiterss.org/en/about
|
||||
[4]:https://launchpad.net/~quiterss/+archive/ubuntu/quiterss/
|
||||
[5]:http://quiterss.org/en/download
|
||||
[6]:http://feedly.com/
|
||||
@ -0,0 +1,72 @@
|
||||
伴随苹果手表的揭幕，Ubuntu智能手表会成为下一个吗？
|
||||
===
|
||||
|
||||
**今天，苹果借助‘苹果手表’的发布，证实了其进军穿戴式计算设备市场的长期传言**
|
||||
|
||||
|
||||
|
||||
Ubuntu智能手表 - 好的主意？
|
||||
|
||||
拥有一系列稳定功能，硬件解决方案和应用合作伙伴关系的支持，手腕穿戴设备被许多公司预示为“人与技术关系的新篇章”。
|
||||
|
||||
它的到来，以及用户兴趣的提升，有可能意味着Ubuntu需要遵循一个为智能手表定制的Ubuntu版本。
|
||||
|
||||
### 大的方面还是成功的 ###
|
||||
|
||||
苹果在正确时间加入了快速发展的智能手表部门。约束手腕穿戴电脑功能的界限并不是一成不变。失败的设计，不良的用户界面以及主流用户使用穿戴技术功能的弱参数化，这些都见证了硬件种类保持着高效的影响力 － 一个准许Cupertino把时间花费在苹果手表上的因素。
|
||||
|
||||
> ‘分析师说：超过2200万的智能手表将在今年销售’
|
||||
|
||||
去年全球范围内可穿戴设备的销售数量（包括健身追踪器）仅仅1000万。今年，分析师希望设备数量的改变可以超过2200万 － 不包括苹果手表，因为其直到2015年初才开始零售。
|
||||
|
||||
很容易就可以看出增长的来源。今年九月初柏林举办的IFA 2014展览会，展示了一系列来自主要制造商们的可穿戴设备，包括索尼和华硕。大多数搭载着Google最新发布的安卓穿戴系统。
|
||||
|
||||
一个更加成熟的表现：安卓穿戴设备打破了与形式因素保持一致的新奇争论，进而呈现出一致并令人折服的用户方案。和新的苹果手表一样，它紧密地连接在一个现存的智能手机生态系统上。
|
||||
|
||||
可能它只是一个使用案例，Ubuntu手腕穿戴系统是否能匹配它还不清楚。
|
||||
|
||||
#### 目前还没有Ubuntu智能手表的计划 ####
|
||||
|
||||
Ubuntu操作系统的通用性，结合以为多装置设备和趋势性未来定制的严格版本，已经产生了典型目标智能电视，平板电脑和智能手机。Mir,公司的本土显示服务器，被用来运转所有尺寸屏幕上的接口（虽然不是公认1.5"的）
|
||||
|
||||
今年年初，Canonical社区负责人Jono Bacon被询问是否有制作Ubuntu智能手表的打算。Bacon提供了他对这个问题的看法：“增加另一个形式因素到[Ubuntu触摸设备]路线只会减缓其余的东西”。
|
||||
|
||||
在Ubuntu电话发布两周年之际，我们还是挺赞同他的想法的。
|
||||
|
||||
滴答，滴答，对冲你的赌注点(实在不懂什么意思...)
|
||||
|
||||
但是并不是没有希望的。在一个[几个月之后的电话采访][1]中，Ubuntu创始人Mark Shuttleworth提及到可穿戴技术和智能电视，平板电脑，智能手机一样，都在公司计划当中。
|
||||
|
||||
> “Ubuntu因其在电话中的完美设计变得独一无二，但是它同时也被设计成满足其余生态系统的样子，比如从穿戴设备到PC机。”
|
||||
|
||||
然而这还没得到具体的证实，它更像一个指针，在这个方向是给我们提供一个乐观的指引。
|
||||
|
||||
### 不可能 — 这就是原因所在 ###
|
||||
|
||||
Canonical并不反对利用牢固的专利进军市场。事实上，它的重要性犹如公司的DHA — 犹如服务器上的RHEL,桌面上的Windows,智能手机上的安卓...
|
||||
|
||||
设备上的Ubuntu系统被制作成可以在更小的屏幕上扩展和适应性运行。甚至很有可能在和手表一样小的屏幕上运行。当普通的代码基础已经在手机，平板电脑，桌面和TV上准备就绪，我想如果我们没有看到来自社区这一方向上的努力，我会感到奇怪。
|
||||
|
||||
但是我之所以不认为它会从规范社区发生，至少目前还没有，是今年早些时候Jono Bacon个人思想的共鸣：时间和努力。
|
||||
|
||||
Tim Cook在他的主题演讲中说道：“*我们并没有追随iPhone，也没有缩水用户界面，将其强硬捆绑在你的手腕上。*”这是一个很明显的陈述。为如此小的屏幕设计UI和UX模型;通过交互原则工作;对硬件和输入模式的恭维，都不是一件容易的事。
|
||||
|
||||
可穿戴技术仍然是一个新兴的市场。在这个阶段，Canonical将会浪费发展，设计以及进行中的业务。在一些更为紧迫的地区，任何利益的重要性将要超过损失。
|
||||
|
||||
玩一局更久的游戏，等待直到看出那些努力在何地成功和失败，这是一条更难的路线。但是更适合Ubuntu的就是今天。在新产品出现之前，让Canonical把力量用在现存的产品上是更好的选择（这是一些已经来迟的理论）
|
||||
|
||||
想更进一步了解什么是Ubuntu智能手表，点击下面的[视频][2]。它展示了一个互动的主体性皮肤Tizen(它已经支持Samsung Galaxy Gear智能手表)。
|
||||
|
||||
---
|
||||
|
||||
via: http://www.omgubuntu.co.uk/2014/09/ubuntu-smartwatch-apple-iwatch
|
||||
|
||||
作者：[Joey-Elijah Sneddon][a]
|
||||
译者：[su-kaiyao](https://github.com/su-kaiyao)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由[LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:https://plus.google.com/117485690627814051450/?rel=author
|
||||
[1]:http://www.omgubuntu.co.uk/2014/03/ubuntu-tablets-coming-year
|
||||
[2]:https://www.youtube.com/embed/8Zf5dktXzEs?feature=oembed
|
||||
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Block a user