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十个非常有趣的 Linux 彩蛋
================================================================================
*制作 Adventure 的程序员悄悄的把一个秘密的功能塞进了游戏里。Atari 并没有对此感到生气，而是给这类“秘密功能”起了个名字——“彩蛋”，因为——你懂的——你会像找复活节彩蛋一样寻找它们。*
![](http://en.wikipedia.org/wiki/File:Adventure_Easteregg.PNG)
*图片来自： Wikipedia*
在1979年的时候，公司为 Atari 2600 开发了一个电子游戏——[Adventure][1]。
制作 Adventure 的程序员悄悄的把这样的一个功能放进了游戏里，当用户把一个“隐形方块”移动到特定的一面墙上时，会让用户进入一个“密室”。那个房间里只有一句话：“Created by [Warren Robinett][2]”——意思是，由 [Warren Robinett][2] 创建。
Atari 有一项反对作者将自己的名字放进他们的游戏里的政策，所以这个无畏的程序员只能偷偷的把自己的名字放进游戏里。Atari 在 Warren Robinett 离开公司之后才发现这个“密室”。Atari 并没有对此感到生气，而是给这类“秘密功能”起了个名字——“彩蛋”，因为——你懂的——你会寻找它们。Atari 还宣布将在之后的游戏中加入更多的“彩蛋”。
这种软件里的“隐藏功能”并不是第一次出现（这类特性的首次出现是在1966年[PDP-10][3]的操作系统上），但这是它第一次有了名字，同时也是第一次真正的被众多电脑用户和游戏玩家所注意。
Linux（以及和Linux相关的软件）也没有被遗忘。这些年来，人们为这个倍受喜爱的操作系统创作了很多非常有趣的彩蛋。下面将介绍我个人最喜爱的彩蛋——以及如何找到它们。
你很快就会想到这些彩蛋大多需要通过终端才能体验到。这是故意的。因为终端比较酷。【我应该借此机机会提醒你一下，如果你想运行我所列出的应用，然而你却还没有安装它们，你是绝对无法运行成功的。你应该先安装好它们的。因为……毕竟只是计算机。】
### Arch : 包管理器（pacman）里的吃豆人（Pac-Man） ###
为了广大的 [Arch Linux][4] 粉丝，我们将以此开篇。你们可以将“[pacman][6]” (Arch 的包管理器)的进度条变成吃豆人吃豆的样子。别问我为什么这不是默认设置。
你需要在你最喜欢的文本编辑器里编辑“/etc/pacman.conf”文件。在“# Misc options”区下面，删除“Color”前的“#”，添加一行“ILoveCandy”。因为吃豆人喜欢糖豆。
没错，这样就行了！下次你在终端里运行pacman管理器时，你就会让这个黄颜色的小家伙吃到些午餐（至少能吃些糖豆）。
### GNU Emacs : 俄罗斯方块（Tetris）以及…… ###
![emacs Tetris](http://www.linux.com/images/stories/41373/emacsTetris.jpg)
*我不喜欢 emacs。一点也不喜欢。但是它确实能玩俄罗斯方块。*
我要坦白一件事：我不喜欢[emacs][7]。一点也不喜欢。
有些东西让我满心欢喜。有些东西能带走我所有伤痛。有些东西能解决我的烦恼。这些[绝对跟 emacs 无关][8]。
但是它确实能玩俄罗斯方块。这可不是件小事。方法如下：
第一步）打开 emacs。（有疑问？输入“emacs”。）
第二步）按下键盘上的Esc和X键。
第三步）输入“tetris”然后按下“Enter”。
玩腻了俄罗斯方块？试试“pong”、“snake”还有其他一堆小游戏（或奇怪的东西）。在“/usr/share/emacs/*/lisp/play”文件中可以看见完整的清单。
### 动物说话了 ###
让动物在终端里说话在 Linux 世界里有着悠久而辉煌的历史。下面这些真的是最应该知道的。
在用基于 Debian 的发行版？试试输入“apt-get moo"。
![apt-get moo](http://www.linux.com/images/stories/41373/AptGetMoo.jpg)
*apt-get moo*
简单？的确。但这是只会说话的牛，所以惹我们喜欢。再试试“aptitude moo”。他会告诉你“There are no Easter Eggs in this program（这个程序里没有彩蛋）”。
关于 [aptitude][9] 有一件事你一定要知道，它是个肮脏、下流的骗子。如果 aptitude 是匹诺曹，那它的鼻子能刺穿月球。在这条命令中添加“-v”选项。不停的添加 v，直到它被逼得投降。
![](http://www.linux.com/images/stories/41373/AptitudeMoo.jpg)
*我猜大家都同意，这是 aptitude 中最重要的功能。*
我猜大家都同意，这是 aptitude 中最重要的功能。但是万一你想把自己的话让一头牛说出来怎么办？这时我们就需要“cowsay”了。
还有，别让“cowsay（牛说）”这个名字把你给骗了。你可以让你的话从各种东西的嘴里说出来。比如一头大象，Calvin，Beavis 甚至可以是 Ghostbusters（捉鬼敢死队）的标志。只需在终端输入“cowsay -l”就能看到所有选项的列表。
![](http://www.linux.com/images/stories/41373/cowsay.jpg)
*你可以让你的话从各种东西的嘴里说出来*
想玩高端点的？你可以用管道把其他应用的输出放到 cowsay 中。试试“fortune | cowsay”。非常有趣。
### Sudo 请无情的侮辱我 ###
当你做错事时希望你的电脑骂你的人请举手。反正，我这样想过。试试这个：
输入“sudo visudo”以打开“sudoers”文件。在文件的开头你很可能会看见几行以“Defaults”开头的文字。在那几行后面添加“Defaults insults”并保存文件。
现在，只要你输错了你的 sudo 密码，你的系统就会骂你。这些可以提高自信的语句包括“听着，煎饼脑袋，我可没时间听这些垃圾。”，“你吃错药了吧？”以及“你被电过以后大脑就跟以前不太一样了是不是？”
把这个设在同事的电脑上会有非常有趣。
### Firefox 是个厚脸皮 ###
这一个不需要终端！太棒了！
打开火狐浏览器。在地址栏填上“about:about”。你将得到火狐浏览器中所有的“about”页。一点也不炫酷，是不是？
现在试试“about:mozilla”，浏览器就会回应你一条从“[Book of Mozilla（Mozilla 之书）][10]”——这本浏览网页的圣经——里引用的话。我的另一个最爱是“about:robots”，这个也很有趣。
![](http://www.linux.com/images/stories/41373/About-Mozilla550.jpg)
*“[Book of Mozilla（Mozilla 之书）][10]”——浏览网页的圣经。*
### 精心调制的混搭日历 ###
是否厌倦了千百年不变的 [Gregorian Calendar（罗马教历）][11]？准备好乱入了吗？试试输入“ddate”。这样会把当前日历以[Discordian Calendar（不和教历）][12]的方式显示出来。你会遇见这样的语句：
“今天是Sweetmorn（甜美的清晨），3181年Discord（不和）季的第18天。”
我听见你在说什么了，“但这根本不是什么彩蛋！”嘘~，闭嘴。只要我想，我就可以把它叫做彩蛋。
### 快速进入黑客行话模式 ###
想不想尝试一下电影里超级黑客的感觉？试试（通过添加“-oS”）把扫描器设置成“[Script Kiddie][13]”模式。然后所有的输出都会变成最3l33t的[黑客范][14]。
例如: “nmap -oS - google.com”
赶快试试。我知道你有多想这么做。你一定会让安吉丽娜·朱莉（Angelina Jolie）[印象深刻][15]
### lolcat彩虹 ###
在你的Linux终端里有很多彩蛋真真是极好的……但是如果你还想要变得……更有魅力些怎么办？输入：lolcat。把任何一个程序的文本输出通过管道输入到lolcat里。你会得到它的超级无敌彩虹版。
![](http://www.linux.com/images/stories/41373/lolcat.jpg)
*把任何一个程序的文本输出通过管道输入到lolcat里。你会得到它的超级无敌彩虹版。*
### 追光标的小家伙 ###
![oneko cat](http://www.linux.com/images/stories/41373/onekocat.jpg)
*“Oneko” -- 经典 “Neko”的Linux移植版本。*
接下来是“Oneko” -- 经典 “[Neko][16]”的Linux移植版本。基本上就是个满屏幕追着你的光标跑的小猫。
虽然严格来它并不算是“彩蛋”，它还是很有趣的。而且感觉上也是很彩蛋的。
你还可以用不同的选项（比如“oneko -dog”）把小猫替代成小狗，或是调成其他样式。用这个对付讨厌的同事有着无限的可能。
就是这些了！一个我最喜欢的Linux彩蛋（或是类似东西）的清单。请尽情的的在下面的评论区留下你的最爱。因为这是互联网。你就能做这些事。
--------------------------------------------------------------------------------
via: http://www.linux.com/news/software/applications/820944-10-truly-amusing-linux-easter-eggs-
作者：[Bryan Lunduke][a]
译者：[H-mudcup](https://github.com/H-mudcup)
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
[a]:http://www.linux.com/community/forums/person/56734
[1]:http://en.wikipedia.org/wiki/Adventure_(Atari_2600)
[2]:http://en.wikipedia.org/wiki/Warren_Robinett
[3]:http://en.wikipedia.org/wiki/PDP-10
[4]:http://en.wikipedia.org/wiki/Arch_Linux
[5]:http://en.wikipedia.org/wiki/Pac-Man
[6]:http://www.linux.com/news/software/applications/820944-10-truly-amusing-linux-easter-eggs-#Pacman
[7]:http://en.wikipedia.org/wiki/GNU_Emacs
[8]:https://www.youtube.com/watch?v=AQ4NAZPi2js
[9]:https://wiki.debian.org/Aptitude
[10]:http://en.wikipedia.org/wiki/The_Book_of_Mozilla
[11]:http://en.wikipedia.org/wiki/Gregorian_calendar
[12]:http://en.wikipedia.org/wiki/Discordian_calendar
[13]:http://nmap.org/book/output-formats-script-kiddie.html
[14]:http://nmap.org/book/output-formats-script-kiddie.html
[15]:https://www.youtube.com/watch?v=Ql1uLyuWra8
[16]:http://en.wikipedia.org/wiki/Neko_%28computer_program%29

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Translating by Love-xuan
动态壁纸给linux发行版添加活力背景
================================================================================
**我们知道你想拥有一个有格调的ubuntu桌面来炫耀一下 ：）**
![Live Wallpaper](http://i.imgur.com/9JIUw5p.gif)
Live Wallpaper
*Live Wallpaper*
在linxu上费一点点劲搭建一个出色的工作环境是很简单的。
今天，我们着重来探讨[重新着重探讨][2]长驻你脑海中那些东西 － 一款自由，开源，能够给你的截图增添光彩的工具。
在linxu上费一点点劲搭建一个出色的工作环境是很简单的。今天，我们（[重新][2]）着重来探讨长驻你脑海中那些东西 ：一款自由，开源，能够给你的截图增添光彩的工具。
它叫 **Live Wallpaper** (正如你猜的那样) ，它用由OpenGL驱动的一款动态桌面背景来代替标准的静态桌面背景。
@ -25,13 +23,13 @@ Live Wallpaper 不是此类软件唯一的一款，但它是最好的一款之
从精细的(‘noise’)到狂热的 (‘nexus’)，包罗万象，甚至有受到Ubuntu Phone欢迎屏幕启发的obligatory锁屏壁纸。
- Circles — 带着‘evolving circle’风格的时钟，灵感来自于Ubuntu Phone
- Galaxy — 支持自定义大小，位置的星系
- Gradient Clock — 覆盖基本梯度的时钟
- Galaxy — 支持自定义大小，位置的旋转星系
- Gradient Clock — 放在倾斜面上的polar时钟
- Nexus — 亮色粒子火花穿越屏幕
- Noise — 类似于iOS动态壁纸的Bokeh设计
- Photoslide — 由文件夹（默认为 ~/Photos）内照片构成的动态网格相册
Live Wallpaper **完全开源** ，所以没有什么能够阻挡天马行空的艺术家用提供的做法（当然还有耐心）来创造他们自己的精美主题。
Live Wallpaper **完全开源**，所以没有什么能够阻挡天马行空的艺术家们用诀窍（当然还有耐心）来创造他们自己的精美主题。
### 设置 & 特点 ###
@ -39,24 +37,24 @@ Live Wallpaper **完全开源** ，所以没有什么能够阻挡天马行空
虽然某些主题与其它主题相比有更多的选项，但每款主题都可以通过某些方式来配置或者定制。
例如, Nexus主题中 (上图所示) 你可以更改脉冲粒子的数量，颜色，大小和出现频率。
例如，Nexus主题中 (上图所示) 你可以更改脉冲粒子的数量，颜色，大小和出现频率。
首选项提供了 **通用选项** 适用于所有主题，包括:
- 设置登陆界面的动态壁纸
- 设置登录界面的动态壁纸
- 自定义动画背景
- 调节 FPS (包括在屏幕上显示FPS)
- 指定多显示器行为
- 指定多显示器的行为
有如此多的选项，diy适用于你自己的桌面背景是很容易的。
### 缺陷 ###
#### 没有桌面图标 ####
Live Wallpaper在运行时，你无法在桌面添加，打开或者是编辑文件和文件夹。
首选项程序提供了一个选项来让你这样做（只是猜测）。也许是它只能在老版本中使用，在我们的测试中－测试环境为Ununtu 14.10,它并没有用。
在测试中发现当把桌面壁纸设置成格式为png的图片文件时，这个选项有用，不需要是透明的png图片文件，只要是png图片文件就行了。
首选项程序提供了一个选项来让你这样做（只是猜测）。也许是它只能在老版本中使用，在我们的测试中－测试环境为Ununtu 14.10，它不工作。但在测试中发现当把桌面壁纸设置成格式为png的图片文件时，这个选项有用，不需要是透明的png图片文件，只要是png图片文件就行了。
#### 资源占用 ####
@ -68,9 +66,9 @@ Live Wallpaper在运行时，你无法在桌面添加，打开或者是编辑文
对我来说最大的“bug”绝对是没有“退出”选项。
当然，Sure, 动态壁纸可以通过托盘图标和首选项完全退出，那退出托盘图标呢？没办法。只能在终端执行命令‘pkill livewallpaper’。
当然，动态壁纸可以通过托盘图标和首选项完全退出，那退出托盘图标呢？没办法。只能在终端执行命令‘pkill livewallpaper’。
### 怎么在 Ubuntu 14.04 LTS +上安装 Live Wallpaper ###
### 怎么在 Ubuntu 14.04 LTS+ 上安装 Live Wallpaper ###
![](http://www.omgubuntu.co.uk/wp-content/uploads/2015/05/terminal-command-750x146.jpg)
@ -81,7 +79,7 @@ Live Wallpaper在运行时，你无法在桌面添加，打开或者是编辑文
sudo apt-get update && sudo apt-get install livewallpaper
你还需要安装 indicator applet, 这样可以方便快速的打开或是关闭动态壁纸，从菜单选择主题，另外图形配置工具可以让你基于你自己的口味来配置每款主题。
你还需要安装 indicator applet，这样可以方便快速的打开或是关闭动态壁纸，从菜单选择主题，另外图形配置工具可以让你基于你自己的口味来配置每款主题。
sudo apt-get install livewallpaper-config livewallpaper-indicator
@ -89,11 +87,11 @@ Live Wallpaper在运行时，你无法在桌面添加，打开或者是编辑文
![](http://www.omgubuntu.co.uk/wp-content/uploads/2015/05/live-wallpaper-app-launcher.png)
让人不爽的是，安装完成后，程序不会自动打开托盘图标，而仅仅将它自己加入自动启动项，所以，快速来个注消 > 登陆它就会出现啦。
让人不爽的是，安装完成后，程序不会自动打开托盘图标，而仅仅将它自己加入自动启动项，所以，快速来个注销 -> 登陆它就会出现啦。
### 总结 ###
如果你正处在无聊呆板的桌面中，幻想有一个更有活力的生活，不防试试。另外，告诉我们你想看到什么样的动态壁纸！
如果你正处在无聊呆板的桌面中，幻想有一个更有活力的生活，不妨试试。另外，告诉我们你想看到什么样的动态壁纸！
--------------------------------------------------------------------------------
@ -101,7 +99,7 @@ via: http://www.omgubuntu.co.uk/2015/05/animated-wallpaper-adds-live-backgrounds
作者：[Joey-Elijah Sneddon][a]
译者：[Love-xuan](https://github.com/Love-xuan)
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](https://linux.cn/) 荣誉推出

43
translated/tech/20150603 Installing Ruby on Rails using rbenv on Ubuntu 15.04.md → published/20150603 Installing Ruby on Rails using rbenv on Ubuntu 15.04.md
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在Ubuntu 15.04中安装RUby on Rails
在Ubuntu 15.04中安装Ruby on Rails
================================================================================
本篇我们会学习如何用rbenv在Ubuntu 15.04中安装Ruby on Rails。我们选择Ubuntu作为操作系统因为Ubuntu是Linux发行版中自带很多包和完整文档的操作系统，因此我认为这是正确的选择。如果你不想安装最新的Ubuntu，你可以从[下载iso文件][1]开始。
本篇我们会学习如何用rbenv在Ubuntu 15.04中安装Ruby on Rails。我们选择Ubuntu作为操作系统是因为Ubuntu是Linux发行版中自带很多包和完整文档的操作系统，因此我认为这是正确的选择。如果你还没有安装最新的Ubuntu，你可以从[下载iso文件][1]开始。
### 安装 Ruby ###
@ -9,9 +10,9 @@
sudo apt-get update
sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev
有三种方法来安装Ruby比如rbenv,rvm和从源码安装。每种都有各自的好处，但是这些天开发者们更倾向使用rbenv而不是rvm和源码来安装。我们将安装最新的Ruby版本，2.2.2。
有三种方法来安装Ruby：rbenv、rvm和从源码安装。每种都有各自的好处，但是近来开发者们更倾向使用rbenv而不是rvm和源码来安装。我们将安装最新的Ruby版本，2.2.2。
用rbenv来安装只有简单的两步。第一步安装rbenv接着是ruby-build：
用rbenv来安装只有简单的两步。第一步安装rbenv，接着是ruby-build：
cd
git clone git://github.com/sstephenson/rbenv.git .rbenv
@ -28,23 +29,23 @@
rbenv global 2.2.2
ruby -v
我们需要安装Bundler但是我们要在安装之前告诉rubygems不要为每个包本地安装文档。
我们需要安装Bundler，但是我们要在安装之前告诉rubygems不要为每个包安装本地文档。
echo "gem: --no-ri --no-rdoc" > ~/.gemrc
gem install bundler
### 配置 GIT ###
配置git之前，你要创建一个github账号，你可以注册[git][2]。我们需要git作为版本控制系统，因此我们要设置来匹配github账号。
配置git之前，你要创建一个github账号，你可以注册一个[github 账号][2]。我们需要git作为版本控制系统，因此我们要设置它来匹配github账号。
用户的github账号来代替下面的**Name** 和 **Email address** 。
用户的github账号来替换下面的**Name** 和 **Email address** 。
git config --global color.ui true
git config --global user.name "YOUR NAME"
git config --global user.email "YOUR@EMAIL.com"
ssh-keygen -t rsa -C "YOUR@EMAIL.com"
接下来用新生成的ssh key添加到github账号中。这样你需要复制下面命令的输出并[粘贴在这][3]。
接下来用新生成的ssh key添加到github账号中。这样你需要复制下面命令的输出并[粘贴在Github的设置页面里面][3]。
cat ~/.ssh/id_rsa.pub
@ -58,7 +59,7 @@
### 安装 Rails ###
我们需要安装javascript运行时，像NodeJS因为这些天Rails带来很多依赖。这样我们可以结合并缩小你的javascript来提供一个更快的生产环境。
我们需要安装像NodeJS这样的javascript运行时环境，因为近来Rails的依赖越来越多了。这样我们可以合并和压缩你的javascript，从而提供一个更快的生产环境。
我们需要添加PPA来安装nodeJS。
@ -66,7 +67,7 @@
sudo apt-get update
sudo apt-get install nodejs
如果在更新是晕倒了问题，你可以试试这个命令：
如果在更新时遇到了问题，你可以试试这个命令：
# Note the new setup script name for Node.js v0.12
curl -sL https://deb.nodesource.com/setup_0.12 | sudo bash -
@ -74,15 +75,15 @@
# Then install with:
sudo apt-get install -y nodejs
下一步，用这个命令：
下一步，用这个命令安装 rails：
gem install rails -v 4.2.1
因为我们正在使用rbenv，用下面的命令来安装rails。
因为我们正在使用rbenv，用下面的命令来让rails的执行程序可以使用。
rbenv rehash
要确保rails已经正确安炸u哪个，你可以运行rails -v，显示如下：
要确保rails已经正确安装，你可以运行rails -v，显示如下：
rails -v
# Rails 4.2.1
@ -91,25 +92,25 @@
### 设置 MySQL ###
或许你已经熟悉MySQL了，你可以从Ubuntu的仓库中安装MySQL的客户端与服务端。你可以在安装时设置root用户密码。这个信息将来会进入你rails程序的database.yml文件中、用下面的命令来安装mysql。
或许你已经熟悉MySQL了，你可以从Ubuntu的仓库中安装MySQL的客户端与服务端。你可以在安装时设置root用户密码。这个信息将来会进入你rails程序的database.yml文件中。用下面的命令来安装mysql。
sudo apt-get install mysql-server mysql-client libmysqlclient-dev
安装libmysqlclient-dev用于提供在设置rails程序时，rails在连接mysql所需要用到的用于编译mysql2 gem的文件。
安装libmysqlclient-dev用于mysql2 gem的编译；在设置rails程序时，rails通过它来连接mysql。
### 最后一步 ###
让我们尝试创建你的第一个rails程序：
# Use MySQL
# 使用 MySQL 数据库
rails new myapp -d mysql
# Move into the application directory
# 进入到应用目录
cd myapp
# Create Database
# 创建数据库
rake db:create
@ -125,7 +126,7 @@
nano config/database.yml
接着输入MySql root用户的密码。
接着填入MySql root用户的密码。
![](http://blog.linoxide.com/wp-content/uploads/2015/05/root_passw.png)
@ -133,7 +134,7 @@
### 总结 ###
Rails是用Ruby写的， 也就是随着rails一起使用的编程语言。在Ubuntu 15.04中Ruby on Rails可以用rbenv、 rvm和源码的方式来安装。本篇我们使用的是rbenv方式并用了MySQL作为数据库。有任何的问题或建议，请在评论栏指出。
Rails是用Ruby写的， 也是随着rails一起使用的编程语言。在Ubuntu 15.04中Ruby on Rails可以用rbenv、 rvm和源码的方式来安装。本篇我们使用的是rbenv方式并用了MySQL作为数据库。有任何的问题或建议，请在评论栏指出。
--------------------------------------------------------------------------------
@ -141,7 +142,7 @@ via: http://linoxide.com/ubuntu-how-to/installing-ruby-rails-using-rbenv-ubuntu-
作者：[Obet][a]
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) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出

69
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@ -0,0 +1,69 @@
原子(Atom)代码编辑器的视频短片介绍
================================================================================
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/06/Atom_stable.png)
[Atom 1.0][1]时代来临。作为[最好的开源代码编辑器]之一，Atom已公开使用快一年了，近段时间，第一个稳定版本的原子编辑器的发布却引起了广大用户的谈论。这个[Github][4]上的项目随着“为21世纪破解文本编辑器”活动的兴起，已近被下载了150万余次，积累35万活跃用户。
### 这是个漫长的过程 ###
滴水穿石，非一日之功，Atom同样经历一个漫长的过程。从2008年首次提出概念到这个月第一个稳定版本的发布，主创人员和全球各地的贡献者，这几年来不断地致力于Atom核心的开发。我们通过下面这张图来了解一下Atom的发展过程：
![Image credit: Atom](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/06/Atom_stable_timeline.jpeg)
*图片来源：Atom*
### 回到未来 ###
Atom 1.0 通过流行的视频发布方式，展示了这款编辑器的潜能。这个视屏就像70年代的科幻连续剧一样，今天你将会看到一个极其酷炫的视屏：
注：youtube视频，不行做个链接吧
<iframe width="640" height="390" frameborder="0" allowfullscreen="true" src="http://www.youtube.com/embed/Y7aEiVwBAdk?version=3&amp;rel=1&amp;fs=1&amp;showsearch=0&amp;showinfo=1&amp;iv_load_policy=1&amp;wmode=transparent" type="text/html" class="youtube-player"></iframe>
### 原子编辑器特点 ###
- 跨平台编辑
- 实现包管理
- 智能化、自动化
- 文件系统视图
- 多窗操作
- 支持查找更换
- 高度个性化
- 界面更新颖
### Atom 1.0起来 ###
Atom 1.0 支持Linux，Windows和Mac OS X。对于基于Debian的Linux，例如Ubuntu和Linux Mint，Atom提供了deb包。对于Fedora，同样有rpm包。如果你愿意，你可以下载源代码。通过下面的链接下载最新的版本。
- [Atom .deb][5]
- [Atom .rpm][6]
- [Atom Source Code][7]
如果你愿意，你可以[通过PPA在Ubuntu上安装Atom]。PPA并不是官方解决方案。
注：下面是一个调查，可以发布的时候在文章内发布个调查
#### 你对Atom感兴趣吗？ ####
- 噢，当然！这是程序员的福音。
- 我并不这样认为。我见过更好的编辑器。
- 并不关心，我的默认编辑器就能胜任我的工作。
--------------------------------------------------------------------------------
via: http://itsfoss.com/atom-stable-released/
作者：[Abhishek][a]
译者：[sevenot](https://github.com/sevenot)
校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
[a]:http://itsfoss.com/author/abhishek/
[1]:http://blog.atom.io/2015/06/25/atom-1-0.html
[2]:http://itsfoss.com/best-modern-open-source-code-editors-for-linux/
[3]:https://atom.io/
[4]:https://github.com/
[5]:https://atom.io/download/deb
[6]:https://atom.io/download/rpm
[7]:https://github.com/atom/atom/blob/master/docs/build-instructions/linux.md
[8]:http://itsfoss.com/install-atom-text-editor-ubuntu-1404-linux-mint-17/

12
translated/tech/20150709 Linux FAQs with Answers--How to fix 'tar--Exiting with failure status due to previous errors'.md → published/20150709 Linux FAQs with Answers--How to fix 'tar--Exiting with failure status due to previous errors'.md
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@ -1,6 +1,7 @@
Linux常见问题解答--如何修复"tar：由于前一个错误导致于失败状态中退出"("Exiting with failure status due to previous errors")
Linux常见问题解答--如何修复"tar：由于前一个错误导致于失败状态中退出"
================================================================================
> **问题**: 当我想试着用tar命令来创建一个压缩文件时，总在执行过程中失败，并且抛出一个错误说明"tar：由于前一个错误导致于失败状态中退出"("Exiting with failure status due to previous errors"). 什么导致这个错误的发生，要如何解决？
![](https://farm9.staticflickr.com/8863/17631029953_1140fe2dd3_b.jpg)
如果当你执行tar命令时，遇到了下面的错误，那么最有可能的原因是对于你想用tar命令压缩的某个文件中，你并不具备其读权限。
@ -13,21 +14,20 @@ Linux常见问题解答--如何修复"tar：由于前一个错误导致于失败
$ tar cvzfz backup.tgz my_program/ > /dev/null
然后你会看到tar输出的标准错误(stderr)信息。
然后你会看到tar输出的标准错误(stderr)信息。（LCTT 译注：自然，不用 v 参数也可以。）
tar: my_program/src/lib/.conf.db.~lock~: Cannot open: Permission denied
tar: Exiting with failure status due to previous errors
你可以从上面的例子中看到，引起错误的原因的确是“读权限不允许”（denied read permission.)
要解决这个问题，只要简单地更改(或移除)问题文件的权限，然后重新执行tar命令即可。
你可以从上面的例子中看到，引起错误的原因的确是“读权限不允许”（denied read permission.)要解决这个问题，只要简单地更改(或移除)问题文件的权限，然后重新执行tar命令即可。
--------------------------------------------------------------------------------
via: http://ask.xmodulo.com/tar-exiting-with-failure-status-due-to-previous-errors.html
作者：[Dan Nanni][a]
译者：[XLCYun(袖里藏云)](https://github.com/译者ID)
校对：[校对者ID](https://github.com/校对者ID)
译者：[XLCYun(袖里藏云)](https://github.com/XLCYun)
校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出

8
translated/tech/20150709 Linux FAQs with Answers--How to open multiple tabs in a GNOME terminal on Ubuntu 15.04.md → published/20150709 Linux FAQs with Answers--How to open multiple tabs in a GNOME terminal on Ubuntu 15.04.md
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@ -1,8 +1,8 @@
Linux 答疑--如何在 Ubuntu 15.04 的 GNOME 终端中开启多个标签
Linux有问必答：如何在 Ubuntu 15.04 的 GNOME 终端中开启多个标签
================================================================================
> **问**: 我以前可以在我的 Ubuntu 台式机中的 gnome-terminal 中开启多个标签。但升到 Ubuntu 15.04 后，我就无法再在 gnome-terminal 窗口中打开新标签了。要怎样做才能在 Ubuntu 15.04 的 gnome-terminal 中打开标签呢？
在 Ubuntu 14.10 或之前的版本中，gnome-terminal 允许你在终端窗口中开启一个新标签或一个终端窗口。但从 Ubuntu 15.04开始，gnome-terminal 移除了“新标签”选项。这实际上并不是一个 bug，而是一个合并新标签和新窗口的举措。GNOME 3.12 引入了 [单独的“开启终端”选项][1]。开启新终端标签的功能从终端菜单移动到了首选项中。
在 Ubuntu 14.10 或之前的版本中，gnome-terminal 允许你在终端窗口中开启一个新标签或一个终端窗口。但从 Ubuntu 15.04开始，gnome-terminal 移除了“新标签”选项。这实际上并不是一个 bug，而是一个合并新标签和新窗口的举措。GNOME 3.12 引入了[单独的“开启终端”选项][1]。开启新终端标签的功能从终端菜单移动到了首选项中。
![](https://farm1.staticflickr.com/562/19286510971_f0abe3e7fb_b.jpg)
@ -29,8 +29,8 @@ Linux 答疑--如何在 Ubuntu 15.04 的 GNOME 终端中开启多个标签
via: http://ask.xmodulo.com/open-multiple-tabs-gnome-terminal-ubuntu.html
作者：[Dan Nanni][a]
译者：[KevSJ](https://github.com/KevSJ)
校对：[校对者ID](https://github.com/校对者ID)
译者：[KevinSJ](https://github.com/KevinSJ)
校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出

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为什么 mysql 里的 ibdata1 文件不断的增长？
================================================================================
![ibdata1 file](https://www.percona.com/blog/wp-content/uploads/2013/08/ibdata1-file.jpg)
我们在 [Percona 支持栏目][1]经常收到关于 MySQL 的 ibdata1 文件的这个问题。
当监控服务器发送一个关于 MySQL 服务器存储的报警时，恐慌就开始了 —— 就是说磁盘快要满了。
一番调查后你意识到大多数地盘空间被 InnoDB 的共享表空间 ibdata1 使用。而你已经启用了 [innodb_file_per_table][2]，所以问题是：
### ibdata1存了什么？ ###
当你启用了 `innodb_file_per_table`，表被存储在他们自己的表空间里，但是共享表空间仍然在存储其它的 InnoDB 内部数据：
- 数据字典，也就是 InnoDB 表的元数据
- 变更缓冲区
- 双写缓冲区
- 撤销日志
其中的一些在 [Percona 服务器][3]上可以被配置来避免增长过大的。例如你可以通过 [innodb_ibuf_max_size][4] 设置最大变更缓冲区，或设置 [innodb_doublewrite_file][5] 来将双写缓冲区存储到一个分离的文件。
MySQL 5.6 版中你也可以创建外部的撤销表空间，所以它们可以放到自己的文件来替代存储到 ibdata1。可以看看这个[文档][6]。
### 什么引起 ibdata1 增长迅速？ ###
当 MySQL 出现问题通常我们需要执行的第一个命令是：
SHOW ENGINE INNODB STATUS/G
这将展示给我们一些很有价值的信息。我们从** TRANSACTION（事务）**部分开始检查，然后我们会发现这个：
---TRANSACTION 36E, ACTIVE 1256288 sec
MySQL thread id 42, OS thread handle 0x7f8baaccc700, query id 7900290 localhost root
show engine innodb status
Trx read view will not see trx with id >= 36F, sees < 36F
这是一个最常见的原因，一个14天前创建的相当老的事务。这个状态是**活动的**，这意味着 InnoDB 已经创建了一个数据的快照，所以需要在**撤销**日志中维护旧页面，以保障数据库的一致性视图，直到事务开始。如果你的数据库有大量的写入任务，那就意味着存储了大量的撤销页。
如果你找不到任何长时间运行的事务，你也可以监控INNODB STATUS 中的其他的变量，“**History list length（历史记录列表长度）**”展示了一些等待清除操作。这种情况下问题经常发生，因为清除线程（或者老版本的主线程）不能像这些记录进来的速度一样快地处理撤销。
### 我怎么检查什么被存储到了 ibdata1 里了？ ###
很不幸，MySQL 不提供查看什么被存储到 ibdata1 共享表空间的信息，但是有两个工具将会很有帮助。第一个是马克·卡拉汉制作的一个修改版 innochecksum ，它发布在[这个漏洞报告][7]里。
它相当易于使用：
# ./innochecksum /var/lib/mysql/ibdata1
0 bad checksum
13 FIL_PAGE_INDEX
19272 FIL_PAGE_UNDO_LOG
230 FIL_PAGE_INODE
1 FIL_PAGE_IBUF_FREE_LIST
892 FIL_PAGE_TYPE_ALLOCATED
2 FIL_PAGE_IBUF_BITMAP
195 FIL_PAGE_TYPE_SYS
1 FIL_PAGE_TYPE_TRX_SYS
1 FIL_PAGE_TYPE_FSP_HDR
1 FIL_PAGE_TYPE_XDES
0 FIL_PAGE_TYPE_BLOB
0 FIL_PAGE_TYPE_ZBLOB
0 other
3 max index_id
全部的 20608 中有 19272 个撤销日志页。**这占用了表空间的 93%**。
第二个检查表空间内容的方式是杰里米·科尔制作的 [InnoDB Ruby 工具][8]。它是个检查 InnoDB 的内部结构的更先进的工具。例如我们可以使用 space-summary 参数来得到每个页面及其数据类型的列表。我们可以使用标准的 Unix 工具来统计**撤销日志**页的数量：
# innodb_space -f /var/lib/mysql/ibdata1 space-summary | grep UNDO_LOG | wc -l
19272
尽管这种特殊的情况下，innochedcksum 更快更容易使用，但是我推荐你使用杰里米的工具去了解更多的 InnoDB 内部的数据分布及其内部结构。
好，现在我们知道问题所在了。下一个问题：
### 我该怎么解决问题？ ###
这个问题的答案很简单。如果你还能提交语句，就做吧。如果不能的话，你必须要杀掉线程开始回滚过程。那将停止 ibdata1 的增长，但是很显然，你的软件会出现漏洞，有些人会遇到错误。现在你知道如何去鉴定问题所在，你需要使用你自己的调试工具或普通的查询日志来找出谁或者什么引起的问题。
如果问题发生在清除线程，解决方法通常是升级到新版本，新版中使用一个独立的清除线程替代主线程。更多信息查看该[文档][9]
### 有什么方法回收已使用的空间么？ ###
没有，目前还没有一个容易并且快速的方法。InnoDB 表空间从不收缩...参见[10 年之久的漏洞报告][10]，最新更新自詹姆斯·戴（谢谢）：
当你删除一些行，这个页被标为已删除稍后重用，但是这个空间从不会被回收。唯一的方法是使用新的 ibdata1 启动数据库。要做这个你应该需要使用 mysqldump 做一个逻辑全备份，然后停止 MySQL 并删除所有数据库、ib_logfile*、ibdata1* 文件。当你再启动 MySQL 的时候将会创建一个新的共享表空间。然后恢复逻辑备份。
### 总结 ###
当 ibdata1 文件增长太快，通常是 MySQL 里长时间运行的被遗忘的事务引起的。尝试去解决问题越快越好（提交或者杀死事务），因为不经过痛苦缓慢的 mysqldump 过程，你就不能回收浪费的磁盘空间。
也是非常推荐监控数据库以避免这些问题。我们的 [MySQL 监控插件][11]包括一个 Nagios 脚本，如果发现了一个太老的运行事务它可以提醒你。
--------------------------------------------------------------------------------
via: https://www.percona.com/blog/2013/08/20/why-is-the-ibdata1-file-continuously-growing-in-mysql/
作者：[Miguel Angel Nieto][a]
译者：[wyangsun](https://github.com/wyangsun)
校对：[wxy](https://github.com/wxy)
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
[a]:https://www.percona.com/blog/author/miguelangelnieto/
[1]:https://www.percona.com/products/mysql-support
[2]:http://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html#sysvar_innodb_file_per_table
[3]:https://www.percona.com/software/percona-server
[4]:https://www.percona.com/doc/percona-server/5.5/scalability/innodb_insert_buffer.html#innodb_ibuf_max_size
[5]:https://www.percona.com/doc/percona-server/5.5/performance/innodb_doublewrite_path.html?id=percona-server:features:percona_innodb_doublewrite_path#innodb_doublewrite_file
[6]:http://dev.mysql.com/doc/refman/5.6/en/innodb-performance.html#innodb-undo-tablespace
[7]:http://bugs.mysql.com/bug.php?id=57611
[8]:https://github.com/jeremycole/innodb_ruby
[9]:http://dev.mysql.com/doc/innodb/1.1/en/innodb-improved-purge-scheduling.html
[10]:http://bugs.mysql.com/bug.php?id=1341
[11]:https://www.percona.com/software/percona-monitoring-plugins

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Translating by H-mudcup
10 Truly Amusing Easter Eggs in Linux
================================================================================
![](http://en.wikipedia.org/wiki/File:Adventure_Easteregg.PNG)
The programmer working on Adventure slipped a secret feature into the game. Instead of getting upset about it, Atari decided to give these sorts of “secret features” a name -- “Easter Eggs” because… you know… you hunt for them. Image credit: Wikipedia.
Back in 1979, a video game was being developed for the Atari 2600 -- [Adventure][1].
The programmer working on Adventure slipped a secret feature into the game which, when the user moved an “invisible square” to a particular wall, allowed entry into a “secret room”. That room contained a simple phrase: “Created by [Warren Robinett][2]”.
Atari had a policy against putting author credits in their games, so this intrepid programmer put his John Hancock on the game by being, well, sneaky. Atari only found out about the “secret room” after Warren Robinett had left the company. Instead of getting upset about it, Atari decided to give these sorts of “secret features” a name -- “Easter Eggs” because… you know… you hunt for them -- and declared that they would be putting more of these “Easter Eggs” in future games.
This wasn’t the first such “hidden feature” built into a piece of software (that distinction goes to an operating system for the [PDP-10][3] from 1966, but this was the first time it was given a name. And it was the first time it really grabbed the attention of most computer users and gamers.
Linux (and Linux related software) has not been left out. Some truly amusing Easter Eggs have been created for our beloved operating system over the years. Here are some of my personal favorites -- with how to achieve them.
You’ll notice, rather quickly, that most of these are experienced via a terminal. That’s on purpose. Because terminals are cool. [I should also take this moment to say that if you try to run an application I list, and you do not have it installed, it will not work. You should install it first. Because… computers.]
### Arch : Pac-Man in pacman ###
We’re going to start with one just for the [Arch Linux][4] fans out there. You can add a [Pac-Man][5]-esque character to your progress bars in “[pacman][6]” (the Arch package manager). Why this isn’t enabled by default is beyond me.
To do this you’ll want to edit “/etc/pacman.conf” in your favorite text editor. Under the “# Misc options” section, remove the “#” in front of “Color” and add the line “ILoveCandy”. Because Pac-Man loves candy.
That’s it! Next time you fire up a terminal and run pacman, you’ll help the little yellow guy get some lunch (or at least some candy).
### GNU Emacs : Tetris and such ###
![emacs Tetris](http://www.linux.com/images/stories/41373/emacsTetris.jpg)
I don’t like emacs. Not even a little bit. But it does play Tetris.
I have a confession to make: I don’t like [emacs][7]. Not even a little bit.
Some things fill my heart with gladness. Some things take away all my sadness. Some things ease my troubles. That’s [not what emacs does][8].
But it does play Tetris. And that’s not nothing. Here’s how:
Step 1) Launch emacs. (When in doubt, type “emacs”.)
Step 2) Hit Escape then X on your keyboard.
Step 3) Type “tetris” and hit Enter.
Bored of Tetris? Try “pong”, “snake” and a whole host of other little games (and novelties). Take a look in “/usr/share/emacs/*/lisp/play” for the full list.
### Animals Saying Things ###
The Linux world has a long and glorious history of animals saying things in a terminal. Here are the ones that are the most important to know by heart.
On a Debian-based distro? Try typing “apt-get moo".
![apt-get moo](http://www.linux.com/images/stories/41373/AptGetMoo.jpg)
apt-get moo
Simple, sure. But it’s a talking cow. So we like it. Then try “aptitude moo”. It will inform you that “There are no Easter Eggs in this program”.
If there’s one thing you should know about [aptitude][9], it’s that it’s a dirty, filthy liar. If aptitude were wearing pants, the fire could be seen from space. Add a “-v” option to that same command. Keep adding more v’s until you force aptitude to come clean.
![](http://www.linux.com/images/stories/41373/AptitudeMoo.jpg)
I think we can all agree, that this is probably the most important feature in aptitude.
I think we can all agree, that this is probably the most important feature in aptitude. But what if you want to put your own words into the mouth of a cow? That’s where “cowsay” comes in.
And, don’t let the name “cowsay” fool you. You can put words into so much more than just a cow. Like an elephant, Calvin, Beavis and even the Ghostbusters logo. Just do a “cowsay -l” from the terminal to get a complete list of options.
![](http://www.linux.com/images/stories/41373/cowsay.jpg)
You can put words into so much more than just a cow.
Want to get really tricky? You can pipe the output of other applications into cowsay. Try “fortune | cowsay”. Lots of fun can be had.
### Sudo Insult Me Please ###
Raise your hand if you’ve always wanted your computer to insult you when you do something wrong. Hell. I know I have. Try this:
Type “sudo visudo” to open the “sudoers” file. In the top of that file you’ll likely see a few lines that start with “Defaults”. At the bottom of that list add “Defaults insults” and save the file.
Now, whenever you mistype your sudo password, your system will lob insults at you. Confidence boosting phrases such as “Listen, burrito brains, I don’t have time to listen to this trash.”, “Are you on drugs?” and “You’re mind just hasn’t been the same since the electro-shocks, has it?”.
This one has the side-effect of being a rather fun thing to set on a co-worker's computer.
### Firefox is cheeky ###
Here’s one that isn’t done from the Terminal! Huzzah!
Open up Firefox. In the URL bar type “about:about”. That will give you a list of all of the “about” pages in Firefox. Nothing too fancy there, right?
Now try “about:mozilla” and you’ll be greeted with a quote from the “[Book of Mozilla][10]” -- the holy book of web browsing. One of my other favorites, “about:robots”, is also quite excellent.
![](http://www.linux.com/images/stories/41373/About-Mozilla550.jpg)
The “Book of Mozilla” -- the holy book of web browsing.
### Carefully Crafted Calendar Concoctions ###
Tired of the boring old [Gregorian Calendar][11]? Ready to mix things up a little bit? Try typing “ddate”. This will print the current date on the [Discordian Calendar][12]. You will be greeted by something that looks like this:
“Today is Sweetmorn, the 18th day of Discord in the YOLD 3181”
I hear what you’re saying, “But, this isn’t an Easter Egg!” Shush. I’ll call it an Easter Egg if I want to.
### Instant l33t Hacker Mode ###
Want to feel like you’re a super-hacker from a movie? Try setting nmap into “[Script Kiddie][13]” mode (by adding “-oS”) and all of the output will be rendered in the most 3l33t [h@x0r-y way][14] possible.
Example: “nmap -oS - google.com”
Do it. You know you want to. Angelina Jolie would be [super impressed][15].
### The lolcat Rainbow ###
Having awesome Easter Eggs and goodies in your Linux terminal is fine and dandy… but what if you want it to have a little more… pizazz? Enter: lolcat. Take the text output of any program and pipe it through lolcat to super-duper-rainbow-ize it.
![](http://www.linux.com/images/stories/41373/lolcat.jpg)
Take the text output of any program and pipe it through lolcat to super-duper-rainbow-ize it.
### Cursor Chasing Critter ###
![oneko cat](http://www.linux.com/images/stories/41373/onekocat.jpg)
“Oneko” -- the Linux port of the classic “Neko”.
“Oneko” -- the Linux port of the classic “[Neko][16]”.
And that brings us to “oneko” -- the Linux port of the classic “Neko”. Basically a little cat that chases your cursor around the screen.
While this may not qualify as an “Easter Egg” in the strictest sense of the word, it’s still fun. And it feels Easter Egg-y.
You can also use different options (such as “oneko -dog”) to use a little dog instead of a cat and a few other tweaks and options. Lots of possibilities for annoying co-workers with this one.
There you have it! A list of my favorite Linux Easter Eggs (and things of that ilk). Feel free to add your own favorite in the comments section below. Because this is the Internet. And you can do that sort of thing.
--------------------------------------------------------------------------------
via: http://www.linux.com/news/software/applications/820944-10-truly-amusing-linux-easter-eggs-
作者：[Bryan Lunduke][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.linux.com/community/forums/person/56734
[1]:http://en.wikipedia.org/wiki/Adventure_(Atari_2600)
[2]:http://en.wikipedia.org/wiki/Warren_Robinett
[3]:http://en.wikipedia.org/wiki/PDP-10
[4]:http://en.wikipedia.org/wiki/Arch_Linux
[5]:http://en.wikipedia.org/wiki/Pac-Man
[6]:http://www.linux.com/news/software/applications/820944-10-truly-amusing-linux-easter-eggs-#Pacman
[7]:http://en.wikipedia.org/wiki/GNU_Emacs
[8]:https://www.youtube.com/watch?v=AQ4NAZPi2js
[9]:https://wiki.debian.org/Aptitude
[10]:http://en.wikipedia.org/wiki/The_Book_of_Mozilla
[11]:http://en.wikipedia.org/wiki/Gregorian_calendar
[12]:http://en.wikipedia.org/wiki/Discordian_calendar
[13]:http://nmap.org/book/output-formats-script-kiddie.html
[14]:http://nmap.org/book/output-formats-script-kiddie.html
[15]:https://www.youtube.com/watch?v=Ql1uLyuWra8
[16]:http://en.wikipedia.org/wiki/Neko_%28computer_program%29

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Backup with these DeDuplicating Encryption Tools
================================================================================
Data is growing both in volume and value. It is becoming increasingly important to be able to back up and restore this information quickly and reliably. As society has adapted to technology and learned how to depend on computers and mobile devices, there are few that can deal with the reality of losing important data. Of firms that suffer the loss of data, 30% fold within a year, 70% cease trading within five years. This highlights the value of data.
With data growing in volume, improving storage utilization is pretty important. In computing, data deduplication is a specialized data compression technique for eliminating duplicate copies of repeating data. This technique therefore improves storage utilization.
Data is not only of interest to its creator. Governments, competitors, criminals, snoopers may be very keen to access your data. They might want to steal your data, extort money from you, or see what you are up to. Enryption is essential to protect your data.
So the solution is a deduplicating encrypting backup software.
Making file backups is an essential activity for all users, yet many users do not take adequate steps to protect their data. Whether a computer is being used in a corporate environment, or for private use, the machine's hard disk may fail without any warning signs. Alternatively, some data loss occurs as a result of human error. Without regular backups being made, data will inevitably be lost even if the services of a specialist recovery organisation are used.
This article provides a quick roundup of 6 deduplicating encryption backup tools.
----------
### Attic ###
Attic is a deduplicating, encrypted, authenticated and compressed backup program written in Python. The main goal of Attic is to provide an efficient and secure way to backup data. The data deduplication technique used makes Attic suitable for daily backups since only the changes are stored.
Features include:
- Easy to use
- Space efficient storage variable block size deduplication is used to reduce the number of bytes stored by detecting redundant data
- Optional data encryption using 256-bit AES encryption. Data integrity and authenticity is verified using HMAC-SHA256
- Off-site backups with SDSH
- Backups mountable as filesystems
Website: [attic-backup.org][1]
----------
### Borg ###
Borg is a fork of Attic. It is a secure open source backup program designed for efficient data storage where only new or modified data is stored.
The main goal of Borg is to provide an efficient and secure way to backup data. The data deduplication technique used makes Borg suitable for daily backups since only the changes are stored. The authenticated encryption makes it suitable for backups to not fully trusted targets.
Borg is written in Python. Borg was created in May 2015 in response to the difficulty of getting new code or larger changes incorporated into Attic.
Features include:
- Easy to use
- Space efficient storage variable block size deduplication is used to reduce the number of bytes stored by detecting redundant data
- Optional data encryption using 256-bit AES encryption. Data integrity and authenticity is verified using HMAC-SHA256
- Off-site backups with SDSH
- Backups mountable as filesystems
Borg is not compatible with Attic.
Website: [borgbackup.github.io/borgbackup][2]
----------
### Obnam ###
Obnam (OBligatory NAMe) is an easy to use, secure Python based backup program. Backups can be stored on local hard disks, or online via the SSH SFTP protocol. The backup server, if used, does not require any special software, on top of SSH.
Obnam performs de-duplication by splitting up file data into chunks, and storing those individually. Generations are incremental backups; Every backup generation looks like a fresh snapshot, but is really incremental. Obnam is developed by Lars Wirzenius.
Features include:
- Easy to use
- Snapshot backups
- Data de-duplication, across files, and backup generations
- Encrypted backups, using GnuPG
- Backup multiple clients to a single repository
- Backup checkpoints (creates a "save" every 100MBs or so)
- Number of options for performance tuning including lru-size and/or upload-queue-size
- MD5 checksum algorithm for recognising duplicate data chunks
- Store backups to a server via SFTP
- Supports both push (i.e. Run on the client) and pull (i.e. Run on the server) methods
Website: [obnam.org][3]
----------
### Duplicity ###
Duplicity incrementally backs up files and directory by encrypting tar-format volumes with GnuPG and uploading them to a remote (or local) file server. To transmit data it can use ssh/scp, local file access, rsync, ftp, and Amazon S3.
Because duplicity uses librsync, the incremental archives are space efficient and only record the parts of files that have changed since the last backup. As the software uses GnuPG to encrypt and/or sign these archives, they will be safe from spying and/or modification by the server.
Currently duplicity supports deleted files, full unix permissions, directories, symbolic links, fifos, etc.
The duplicity package also includes the rdiffdir utility. Rdiffdir is an extension of librsync's rdiff to directories; it can be used to produce signatures and deltas of directories as well as regular files.
Features include:
- Simple to use
- Encrypted and signed archives (using GnuPG)
- Bandwidth and space efficient, using the rsync algorithm
- Standard file format
- Choice of remote protocol
- Local storage
- scp/ssh
- ftp
- rsync
- HSI
- WebDAV
- Amazon S3
Website: [duplicity.nongnu.org][4]
----------
### ZBackup ###
ZBackup is a versatile globally-deduplicating backup tool.
Features include:
- Parallel LZMA or LZO compression of the stored data. You can mix LZMA and LZO in a repository
- Built-in AES encryption of the stored data
- Possibility to delete old backup data
- Use of a 64-bit rolling hash, keeping the amount of soft collisions to zero
- Repository consists of immutable files. No existing files are ever modified
- Written in C++ only with only modest library dependencies
- Safe to use in production
- Possibility to exchange data between repos without recompression
- Uses a 64-bit modified Rabin-Karp rolling hash
Website: [zbackup.org][5]
----------
### bup ###
bup is a program written in Python that backs things up. It's short for "backup". It provides an efficient way to backup a system based on the git packfile format, providing fast incremental saves and global deduplication (among and within files, including virtual machine images).
bup is released under the LGPL version 2 license.
Features include:
- Global deduplication (among and within files, including virtual machine images)
- Uses a rolling checksum algorithm (similar to rsync) to split large files into chunks
- Uses the packfile format from git
- Writes packfiles directly offering fast incremental saves
- Can use "par2" redundancy to recover corrupted backups
- Mount your bup repository as a FUSE filesystem
Website: [bup.github.io][6]
--------------------------------------------------------------------------------
via: http://www.linuxlinks.com/article/20150628060000607/BackupTools.html
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](https://linux.cn/) 荣誉推出
[1]:https://attic-backup.org/
[2]:https://borgbackup.github.io/borgbackup/
[3]:http://obnam.org/
[4]:http://duplicity.nongnu.org/
[5]:http://zbackup.org/
[6]:https://bup.github.io/

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sevenot translating
First Stable Version Of Atom Code Editor Has Been Released
================================================================================
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/06/Atom_stable.png)
[Atom 1.0][1] is here. One of the [best open source code editors][2], [Atom][3] was available for public uses for almost a year but this is the first stable version of the most talked about text/code editor of recent times. Promoted as the “hackable text editor for 21st century”, this project of [Github][4] has already been downloaded 1.5 million times in the past and currently it has over 350,000 monthly active users.
### It’s been a long time ###
Rome was not built in a day and neither was Atom. Since it was first conceptualized in 2008 till the first stable release this month, it has taken several years and hundreds of contributors from across the globe, along with main developers working on Atom core. A quick look at the journey of Atom can be seen in the picture below:
![Image credit: Atom](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/06/Atom_stable_timeline.jpeg)
Image credit: Atom
### Back to the future ###
This launch of Atom 1.0 is announced with a retro video showing the capabilities of the editor. Resembling to 70’s science fiction TV series, this will be the coolest video you are going to watch today :)
注：youtube视频，不行做个链接吧
<iframe width="640" height="390" frameborder="0" allowfullscreen="true" src="http://www.youtube.com/embed/Y7aEiVwBAdk?version=3&amp;rel=1&amp;fs=1&amp;showsearch=0&amp;showinfo=1&amp;iv_load_policy=1&amp;wmode=transparent" type="text/html" class="youtube-player"></iframe>
### Features of Atom text editor ###
- Cross-platform editing
- Built-in package manager
- Smart autocompletion
- File system browser
- Multiple panes
- Find and replace
- Highly customizable
- Modern look
### Get Atom 1.0 ###
Atom 1.0 is available for Linux, Windows and Mac OS X. For Debian based Linux distributions such as Ubuntu and Linux Mint, Atom provides .deb binaries. For Fedora, it also has .rpm binaries. You can also get the source code, if you like. The links below will let you download the latest stable version.
- [Atom .deb][5]
- [Atom .rpm][6]
- [Atom Source Code][7]
If you prefer, you can [install Atom in Ubuntu using PPA][8]. The PPA is not official though.
注：下面是一个调查，可以发布的时候在文章内发布个调查
#### Are you excited about Atom? ####
- Oh Yes! This is the best thing that could happen to programmers.
- Not really. I have seen better editors.
- Don't care. My default text editor does the job just fine.
--------------------------------------------------------------------------------
via: http://itsfoss.com/atom-stable-released/
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](https://linux.cn/) 荣誉推出
[a]:http://itsfoss.com/author/abhishek/
[1]:http://blog.atom.io/2015/06/25/atom-1-0.html
[2]:http://itsfoss.com/best-modern-open-source-code-editors-for-linux/
[3]:https://atom.io/
[4]:https://github.com/
[5]:https://atom.io/download/deb
[6]:https://atom.io/download/rpm
[7]:https://github.com/atom/atom/blob/master/docs/build-instructions/linux.md
[8]:http://itsfoss.com/install-atom-text-editor-ubuntu-1404-linux-mint-17/

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Translating by H-mudcup
Defending the Free Linux World
================================================================================
![](http://www.linuxinsider.com/ai/908455/open-invention-network.jpg)
@ -122,4 +124,4 @@ via: http://www.linuxinsider.com/story/Defending-the-Free-Linux-World-81512.html
[2]:http://www.redhat.com/
[3]:http://www.law.uh.edu/
[4]:http://www.chaoticmoon.com/
[5]:http://www.ieee.org/
[5]:http://www.ieee.org/

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sevenot translating
10 Top Distributions in Demand to Get Your Dream Job
================================================================================
We are coming up with a series of five articles which aims at making you aware of the top skills which will help you in getting yours dream job. In this competitive world you can not rely on one skill. You need to have balanced set of skills. There is no measure of a balanced skill set except a few conventions and statistics which changes from time-to-time.

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XLCYun translating.
Syncthing: A Private, And Secure Tool To Sync Files/Folders Between Computers
================================================================================
### Introduction ###
@ -204,4 +205,4 @@ via: http://www.unixmen.com/syncthing-private-secure-tool-sync-filesfolders-comp
[a]:http://www.unixmen.com/author/sk/
[1]:https://github.com/syncthing/syncthing/releases/tag/v0.10.20
[2]:http://syncthing.net/
[2]:http://syncthing.net/

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ictlyh Translating
PHP Security
================================================================================
![](http://www.codeproject.com/KB/PHP/363897/php_security.jpg)

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How to manage Vim plugins
================================================================================
Vim is a versatile, lightweight text editor on Linux. While its initial learning curve can be overwhelming for an average Linux user, its benefits are completely worthy. As far as the functionality goes, Vim is fully customizable by means of plugins. Due to its high level of configuration, though, you need to spend some time with its plugin system to be able to personalize Vim in an effective way. Luckily, we have several tools that make our life with Vim plugins easier. The one I use on a daily basis is Vundle.
### What is Vundle? ###
[Vundle][1], which stands for Vim Bundle, is a Vim plugin manager. Vundle allows you to install, update, search and clean up Vim plugins very easily. It can also manage your runtime and help with tags. In this tutorial, I am going to show how to install and use Vundle.
### Installing Vundle ###
First, [install Git][2] if you don't have it on your Linux system.
Next, create a directory where Vim plugins will be downloaded and installed. By default, this directory is located at ~/.vim/bundle
$ mkdir -p ~/.vim/bundle
Now go ahead and install Vundle as follows. Note that Vundle itself is another Vim plugin. Thus we install Vundle under ~/.vim/bundle we created earlier.
$ git clone https://github.com/gmarik/Vundle.vim.git ~/.vim/bundle/Vundle.vim
### Configuring Vundle ###
Now set up you .vimrc file as follows:
set nocompatible " This is required
filetype off " This is required
" Here you set up the runtime path
set rtp+=~/.vim/bundle/Vundle.vim
" Initialize vundle
call vundle#begin()
" This should always be the first
Plugin 'gmarik/Vundle.vim'
" This examples are from https://github.com/gmarik/Vundle.vim README
Plugin 'tpope/vim-fugitive'
" Plugin from http://vim-scripts.org/vim/scripts.html
Plugin 'L9'
"Git plugin not hosted on GitHub
Plugin 'git://git.wincent.com/command-t.git'
"git repos on your local machine (i.e. when working on your own plugin)
Plugin 'file:///home/gmarik/path/to/plugin'
" The sparkup vim script is in a subdirectory of this repo called vim.
" Pass the path to set the runtimepath properly.
Plugin 'rstacruz/sparkup', {'rtp': 'vim/'}
" Avoid a name conflict with L9
Plugin 'user/L9', {'name': 'newL9'}
"Every Plugin should be before this line
call vundle#end() " required
Let me explain the above configuration a bit. By default, Vundle downloads and installs Vim plugins from github.com or vim-scripts.org. You can modify the default behavior.
To install from Github:
Plugin 'user/plugin'
To install from http://vim-scripts.org/vim/scripts.html:
Plugin 'plugin_name'
To install from another git repo:
Plugin 'git://git.another_repo.com/plugin'
To install from a local file:
Plugin 'file:///home/user/path/to/plugin'
Also you can customize others such as the runtime path of you plugins, which is really useful if you are programming a plugin yourself, or just want to load it from another directory that is not ~/.vim.
Plugin 'rstacruz/sparkup', {'rtp': 'another_vim_path/'}
If you have plugins with the same names, you can rename you plugin so that it doesn't conflict.
Plugin 'user/plugin', {'name': 'newPlugin'}
### Using Vum Commands ###
Once you have set up you plugins with Vundle, you can use it to to install, update, search and clean unused plugins using several Vundle commands.
#### Installing a new plugin ####
The PluginInstall command will install all plugins listed in your .vimrc file. You can also install just one specific plugin by passing its name.
:PluginInstall
:PluginInstall <plugin-name>
![](https://farm1.staticflickr.com/559/18998707843_438cd55463_c.jpg)
#### Cleaning up an unused plugin ####
If you have any unused plugin, you can remove it by using the PluginClean command.
:PluginClean
![](https://farm4.staticflickr.com/3814/19433047689_17d9822af6_c.jpg)
#### Searching for a plugin ####
If you want to install a plugin from a plugin list provided, search functionality can be useful.
:PluginSearch <text-list>
![](https://farm1.staticflickr.com/541/19593459846_75b003443d_c.jpg)
While searching, you can install, clean, research or reload the same list on the interactive split. Installing plugins won't load your plugins automatically. To do so, add them to you .vimrc file.
### Conclusion ###
Vim is an amazing tool. It can not only be a great default text editor that can make your work flow faster and smoother, but also be turned into an IDE for almost any programming language available. Vundle can be a big help in personalizing the powerful Vim environment quickly and easily.
Note that there are several sites that allow you to find the right Vim plugins for you. Always check [http://www.vim-scripts.org][3], Github or [http://www.vimawesome.com][4] for new scripts or plugins. Also remember to use the help provider for you plugin.
Keep rocking with your favorite text editor!
--------------------------------------------------------------------------------
via: http://xmodulo.com/manage-vim-plugins.html
作者：[Christopher Valerio][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)
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[1]:https://github.com/VundleVim/Vundle.vim
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struggling 翻译中
Introduction to RAID, Concepts of RAID and RAID Levels – Part 1
================================================================================
RAID is a Redundant Array of Inexpensive disks, but nowadays it is called Redundant Array of Independent drives. Earlier it is used to be very costly to buy even a smaller size of disk, but nowadays we can buy a large size of disk with the same amount like before. Raid is just a collection of disks in a pool to become a logical volume.
![RAID in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/RAID.jpg)
Understanding RAID Setups in Linux
Raid contains groups or sets or Arrays. A combine of drivers make a group of disks to form a RAID Array or RAID set. It can be a minimum of 2 number of disk connected to a raid controller and make a logical volume or more drives can be in a group. Only one Raid level can be applied in a group of disks. Raid are used when we need excellent performance. According to our selected raid level, performance will differ. Saving our data by fault tolerance & high availability.
This series will be titled Preparation for the setting up RAID ‘s through Parts 1-9 and covers the following topics.
- Part 1: Introduction to RAID, Concepts of RAID and RAID Levels
- Part 2: How to setup RAID0 (Stripe) in Linux
- Part 3: How to setup RAID1 (Mirror) in Linux
- Part 4: How to setup RAID5 (Striping with Distributed Parity) in Linux
- Part 5: How to setup RAID6 (Striping with Double Distributed Parity) in Linux
- Part 6: Setting Up RAID 10 or 1+0 (Nested) in Linux
- Part 7: Growing an Existing RAID Array and Removing Failed Disks in Raid
- Part 8: Recovering (Rebuilding) failed drives in RAID
- Part 9: Managing RAID in Linux
This is the Part 1 of a 9-tutorial series, here we will cover the introduction of RAID, Concepts of RAID and RAID Levels that are required for the setting up RAID in Linux.
### Software RAID and Hardware RAID ###
Software RAID have low performance, because of consuming resource from hosts. Raid software need to load for read data from software raid volumes. Before loading raid software, OS need to get boot to load the raid software. No need of Physical hardware in software raids. Zero cost investment.
Hardware RAID have high performance. They are dedicated RAID Controller which is Physically built using PCI express cards. It won’t use the host resource. They have NVRAM for cache to read and write. Stores cache while rebuild even if there is power-failure, it will store the cache using battery power backups. Very costly investments needed for a large scale.
Hardware RAID Card will look like below:
![Hardware RAID](http://www.tecmint.com/wp-content/uploads/2014/10/Hardware-RAID.jpg)
Hardware RAID
#### Featured Concepts of RAID ####
- Parity method in raid regenerate the lost content from parity saved information’s. RAID 5, RAID 6 Based on Parity.
- Stripe is sharing data randomly to multiple disk. This won’t have full data in a single disk. If we use 3 disks half of our data will be in each disks.
- Mirroring is used in RAID 1 and RAID 10. Mirroring is making a copy of same data. In RAID 1 it will save the same content to the other disk too.
- Hot spare is just a spare drive in our server which can automatically replace the failed drives. If any one of the drive failed in our array this hot spare drive will be used and rebuild automatically.
- Chunks are just a size of data which can be minimum from 4KB and more. By defining chunk size we can increase the I/O performance.
RAID’s are in various Levels. Here we will see only the RAID Levels which is used mostly in real environment.
- RAID0 = Striping
- RAID1 = Mirroring
- RAID5 = Single Disk Distributed Parity
- RAID6 = Double Disk Distributed Parity
- RAID10 = Combine of Mirror & Stripe. (Nested RAID)
RAID are managed using mdadm package in most of the Linux distributions. Let us get a Brief look into each RAID Levels.
#### RAID 0 (or) Striping ####
Striping have a excellent performance. In Raid 0 (Striping) the data will be written to disk using shared method. Half of the content will be in one disk and another half will be written to other disk.
Let us assume we have 2 Disk drives, for example, if we write data “TECMINT” to logical volume it will be saved as ‘T‘ will be saved in first disk and ‘E‘ will be saved in Second disk and ‘C‘ will be saved in First disk and again ‘M‘ will be saved in Second disk and it continues in round-robin process.
In this situation if any one of the drive fails we will loose our data, because with half of data from one of the disk can’t use to rebuilt the raid. But while comparing to Write Speed and performance RAID 0 is Excellent. We need at least minimum 2 disks to create a RAID 0 (Striping). If you need your valuable data don’t use this RAID LEVEL.
- High Performance.
- There is Zero Capacity Loss in RAID 0
- Zero Fault Tolerance.
- Write and Reading will be good performance.
#### RAID 1 (or) Mirroring ####
Mirroring have a good performance. Mirroring can make a copy of same data what we have. Assuming we have two numbers of 2TB Hard drives, total there we have 4TB, but in mirroring while the drives are behind the RAID Controller to form a Logical drive Only we can see the 2TB of logical drive.
While we save any data, it will write to both 2TB Drives. Minimum two drives are needed to create a RAID 1 or Mirror. If a disk failure occurred we can reproduce the raid set by replacing a new disk. If any one of the disk fails in RAID 1, we can get the data from other one as there was a copy of same content in the other disk. So there is zero data loss.
- Good Performance.
- Here Half of the Space will be lost in total capacity.
- Full Fault Tolerance.
- Rebuilt will be faster.
- Writing Performance will be slow.
- Reading will be good.
- Can be used for operating systems and database for small scale.
#### RAID 5 (or) Distributed Parity ####
RAID 5 is mostly used in enterprise levels. RAID 5 work by distributed parity method. Parity info will be used to rebuild the data. It rebuilds from the information left on the remaining good drives. This will protect our data from drive failure.
Assume we have 4 drives, if one drive fails and while we replace the failed drive we can rebuild the replaced drive from parity informations. Parity information’s are Stored in all 4 drives, if we have 4 numbers of 1TB hard-drive. The parity information will be stored in 256GB in each drivers and other 768GB in each drives will be defined for Users. RAID 5 can be survive from a single Drive failure, If drives fails more than 1 will cause loss of data’s.
- Excellent Performance
- Reading will be extremely very good in speed.
- Writing will be Average, slow if we won’t use a Hardware RAID Controller.
- Rebuild from Parity information from all drives.
- Full Fault Tolerance.
- 1 Disk Space will be under Parity.
- Can be used in file servers, web servers, very important backups.
#### RAID 6 Two Parity Distributed Disk ####
RAID 6 is same as RAID 5 with two parity distributed system. Mostly used in a large number of arrays. We need minimum 4 Drives, even if there 2 Drive fails we can rebuild the data while replacing new drives.
Very slower than RAID 5, because it writes data to all 4 drivers at same time. Will be average in speed while we using a Hardware RAID Controller. If we have 6 numbers of 1TB hard-drives 4 drives will be used for data and 2 drives will be used for Parity.
- Poor Performance.
- Read Performance will be good.
- Write Performance will be Poor if we not using a Hardware RAID Controller.
- Rebuild from 2 Parity Drives.
- Full Fault tolerance.
- 2 Disks space will be under Parity.
- Can be Used in Large Arrays.
- Can be use in backup purpose, video streaming, used in large scale.
#### RAID 10 (or) Mirror & Stripe ####
RAID 10 can be called as 1+0 or 0+1. This will do both works of Mirror & Striping. Mirror will be first and stripe will be the second in RAID 10. Stripe will be the first and mirror will be the second in RAID 01. RAID 10 is better comparing to 01.
Assume, we have 4 Number of drives. While I’m writing some data to my logical volume it will be saved under All 4 drives using mirror and stripe methods.
If I’m writing a data “TECMINT” in RAID 10 it will save the data as follow. First “T” will write to both disks and second “E” will write to both disk, this step will be used for all data write. It will make a copy of every data to other disk too.
Same time it will use the RAID 0 method and write data as follow “T” will write to first disk and “E” will write to second disk. Again “C” will write to first Disk and “M” to second disk.
- Good read and write performance.
- Here Half of the Space will be lost in total capacity.
- Fault Tolerance.
- Fast rebuild from copying data.
- Can be used in Database storage for high performance and availability.
### Conclusion ###
In this article we have seen what is RAID and which levels are mostly used in RAID in real environment. Hope you have learned the write-up about RAID. For RAID setup one must know about the basic Knowledge about RAID. The above content will fulfil basic understanding about RAID.
In the next upcoming articles I’m going to cover how to setup and create a RAID using Various Levels, Growing a RAID Group (Array) and Troubleshooting with failed Drives and much more.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/understanding-raid-setup-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/

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struggling 翻译中
Creating Software RAID0 (Stripe) on ‘Two Devices’ Using ‘mdadm’ Tool in Linux – Part 2
================================================================================
RAID is Redundant Array of Inexpensive disks, used for high availability and reliability in large scale environments, where data need to be protected than normal use. Raid is just a collection of disks in a pool to become a logical volume and contains an array. A combine drivers makes an array or called as set of (group).
RAID can be created, if there are minimum 2 number of disk connected to a raid controller and make a logical volume or more drives can be added in an array according to defined RAID Levels. Software Raid are available without using Physical hardware those are called as software raid. Software Raid will be named as Poor man raid.
![Setup RAID0 in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Raid0-in-Linux.jpg)
Setup RAID0 in Linux
Main concept of using RAID is to save data from Single point of failure, means if we using a single disk to store the data and if it’s failed, then there is no chance of getting our data back, to stop the data loss we need a fault tolerance method. So, that we can use some collection of disk to form a RAID set.
#### What is Stripe in RAID 0? ####
Stripe is striping data across multiple disk at the same time by dividing the contents. Assume we have two disks and if we save content to logical volume it will be saved under both two physical disks by dividing the content. For better performance RAID 0 will be used, but we can’t get the data if one of the drive fails. So, it isn’t a good practice to use RAID 0. The only solution is to install operating system with RAID0 applied logical volumes to safe your important files.
- RAID 0 has High Performance.
- Zero Capacity Loss in RAID 0. No Space will be wasted.
- Zero Fault Tolerance ( Can’t get back the data if any one of disk fails).
- Write and Reading will be Excellent.
#### Requirements ####
Minimum number of disks are allowed to create RAID 0 is 2, but you can add more disk but the order should be twice as 2, 4, 6, 8. If you have a Physical RAID card with enough ports, you can add more disks.
Here we are not using a Hardware raid, this setup depends only on Software RAID. If we have a physical hardware raid card we can access it from it’s utility UI. Some motherboard by default in-build with RAID feature, there UI can be accessed using Ctrl+I keys.
If you’re new to RAID setups, please read our earlier article, where we’ve covered some basic introduction of about RAID.
- [Introduction to RAID and RAID Concepts][1]
**My Server Setup**
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.225
Two Disks : 20 GB each
This article is Part 2 of a 9-tutorial RAID series, here in this part, we are going to see how we can create and setup Software RAID0 or striping in Linux systems or servers using two 20GB disks named sdb and sdc.
### Step 1: Updating System and Installing mdadm for Managing RAID ###
1. Before setting up RAID0 in Linux, let’s do a system update and then install ‘mdadm‘ package. The mdadm is a small program, which will allow us to configure and manage RAID devices in Linux.
# yum clean all && yum update
# yum install mdadm -y
![install mdadm in linux](http://www.tecmint.com/wp-content/uploads/2014/10/install-mdadm-in-linux.png)
Install mdadm Tool
### Step 2: Verify Attached Two 20GB Drives ###
2. Before creating RAID 0, make sure to verify that the attached two hard drives are detected or not, using the following command.
# ls -l /dev | grep sd
![Check Hard Drives in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Check-Hard-Drives.png)
Check Hard Drives
3. Once the new hard drives detected, it’s time to check whether the attached drives are already using any existing raid with the help of following ‘mdadm’ command.
# mdadm --examine /dev/sd[b-c]
![Check RAID Devices in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Check-Drives-using-RAID.png)
Check RAID Devices
In the above output, we come to know that none of the RAID have been applied to these two sdb and sdc drives.
### Step 3: Creating Partitions for RAID ###
4. Now create sdb and sdc partitions for raid, with the help of following fdisk command. Here, I will show how to create partition on sdb drive.
# fdisk /dev/sdb
Follow below instructions for creating partitions.
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition.
- Next select the partition number as 1.
- Give the default value by just pressing two times Enter key.
- Next press ‘P‘ to print the defined partition.
![Create Partitions in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Create-Partitions-in-Linux.png)
Create Partitions
Follow below instructions for creating Linux raid auto on partitions.
- Press ‘L‘ to list all available types.
- Type ‘t‘to choose the partitions.
- Choose ‘fd‘ for Linux raid auto and press Enter to apply.
- Then again use ‘P‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Create RAID Partitions](http://www.tecmint.com/wp-content/uploads/2014/10/Create-RAID-Partitions.png)
Create RAID Partitions in Linux
**Note**: Please follow same above instructions to create partition on sdc drive now.
5. After creating partitions, verify both the drivers are correctly defined for RAID using following command.
# mdadm --examine /dev/sd[b-c]
# mdadm --examine /dev/sd[b-c]1
![Verify RAID Partitions](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-RAID-Partitions.png)
Verify RAID Partitions
### Step 4: Creating RAID md Devices ###
6. Now create md device (i.e. /dev/md0) and apply raid level using below command.
# mdadm -C /dev/md0 -l raid0 -n 2 /dev/sd[b-c]1
# mdadm --create /dev/md0 --level=stripe --raid-devices=2 /dev/sd[b-c]1
- -C – create
- -l – level
- -n – No of raid-devices
7. Once md device has been created, now verify the status of RAID Level, Devices and Array used, with the help of following series of commands as shown.
# cat /proc/mdstat
![Verify RAID Level](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-RAID-Level.png)
Verify RAID Level
# mdadm -E /dev/sd[b-c]1
![Verify RAID Device](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-RAID-Device.png)
Verify RAID Device
# mdadm --detail /dev/md0
![Verify RAID Array](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-RAID-Array.png)
Verify RAID Array
### Step 5: Assiging RAID Devices to Filesystem ###
8. Create a ext4 filesystem for a RAID device /dev/md0 and mount it under /dev/raid0.
# mkfs.ext4 /dev/md0
![Create ext4 Filesystem in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Create-ext4-Filesystem.png)
Create ext4 Filesystem
9. Once ext4 filesystem has been created for Raid device, now create a mount point directory (i.e. /mnt/raid0) and mount the device /dev/md0 under it.
# mkdir /mnt/raid0
# mount /dev/md0 /mnt/raid0/
10. Next, verify that the device /dev/md0 is mounted under /mnt/raid0 directory using df command.
# df -h
11. Next, create a file called ‘tecmint.txt‘ under the mount point /mnt/raid0, add some content to the created file and view the content of a file and directory.
# touch /mnt/raid0/tecmint.txt
# echo "Hi everyone how you doing ?" > /mnt/raid0/tecmint.txt
# cat /mnt/raid0/tecmint.txt
# ls -l /mnt/raid0/
![Verify Mount Device](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-Mount-Device.png)
Verify Mount Device
12. Once you’ve verified mount points, it’s time to create an fstab entry in /etc/fstab file.
# vim /etc/fstab
Add the following entry as described. May vary according to your mount location and filesystem you using.
/dev/md0 /mnt/raid0 ext4 deaults 0 0
![Add Device to Fstab](http://www.tecmint.com/wp-content/uploads/2014/10/Add-Device-to-Fstab.png)
Add Device to Fstab
13. Run mount ‘-a‘ to check if there is any error in fstab entry.
# mount -av
![Check Errors in Fstab](http://www.tecmint.com/wp-content/uploads/2014/10/Check-Errors-in-Fstab.png)
Check Errors in Fstab
### Step 6: Saving RAID Configurations ###
14. Finally, save the raid configuration to one of the file to keep the configurations for future use. Again we use ‘mdadm’ command with ‘-s‘ (scan) and ‘-v‘ (verbose) options as shown.
# mdadm -E -s -v >> /etc/mdadm.conf
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
# cat /etc/mdadm.conf
![Save RAID Configurations](http://www.tecmint.com/wp-content/uploads/2014/10/Save-RAID-Configurations.png)
Save RAID Configurations
That’s it, we have seen here, how to configure RAID0 striping with raid levels by using two hard disks. In next article, we will see how to setup RAID5.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/create-raid0-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/
[1]:http://www.tecmint.com/understanding-raid-setup-in-linux/

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struggling 翻译中
Setting up RAID 1 (Mirroring) using ‘Two Disks’ in Linux – Part 3
================================================================================
RAID Mirroring means an exact clone (or mirror) of the same data writing to two drives. A minimum two number of disks are more required in an array to create RAID1 and it’s useful only, when read performance or reliability is more precise than the data storage capacity.
![Create Raid1 in Linux](http://www.tecmint.com/wp-content/uploads/2014/10/Create-RAID1-in-Linux.jpeg)
Setup Raid1 in Linux
Mirrors are created to protect against data loss due to disk failure. Each disk in a mirror involves an exact copy of the data. When one disk fails, the same data can be retrieved from other functioning disk. However, the failed drive can be replaced from the running computer without any user interruption.
### Features of RAID 1 ###
- Mirror has Good Performance.
- 50% of space will be lost. Means if we have two disk with 500GB size total, it will be 1TB but in Mirroring it will only show us 500GB.
- No data loss in Mirroring if one disk fails, because we have the same content in both disks.
- Reading will be good than writing data to drive.
#### Requirements ####
Minimum Two number of disks are allowed to create RAID 1, but you can add more disks by using twice as 2, 4, 6, 8. To add more disks, your system must have a RAID physical adapter (hardware card).
Here we’re using software raid not a Hardware raid, if your system has an inbuilt physical hardware raid card you can access it from it’s utility UI or using Ctrl+I key.
Read Also: [Basic Concepts of RAID in Linux][1]
#### My Server Setup ####
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.226
Hostname : rd1.tecmintlocal.com
Disk 1 [20GB] : /dev/sdb
Disk 2 [20GB] : /dev/sdc
This article will guide you through a step-by-step instructions on how to setup a software RAID 1 or Mirror using mdadm (creates and manages raid) on Linux Platform. Although the same instructions also works on other Linux distributions such as RedHat, CentOS, Fedora, etc.
### Step 1: Installing Prerequisites and Examine Drives ###
1. As I said above, we’re using mdadm utility for creating and managing RAID in Linux. So, let’s install the mdadm software package on Linux using yum or apt-get package manager tool.
# yum install mdadm [on RedHat systems]
# apt-get install mdadm [on Debain systems]
2. Once ‘mdadm‘ package has been installed, we need to examine our disk drives whether there is already any raid configured using the following command.
# mdadm -E /dev/sd[b-c]
![Check RAID on Disks](http://www.tecmint.com/wp-content/uploads/2014/10/Check-RAID-on-Disks.png)
Check RAID on Disks
As you see from the above screen, that there is no any super-block detected yet, means no RAID defined.
### Step 2: Drive Partitioning for RAID ###
3. As I mentioned above, that we’re using minimum two partitions /dev/sdb and /dev/sdc for creating RAID1. Let’s create partitions on these two drives using ‘fdisk‘ command and change the type to raid during partition creation.
# fdisk /dev/sdb
Follow the below instructions
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition.
- Next select the partition number as 1.
- Give the default full size by just pressing two times Enter key.
- Next press ‘p‘ to print the defined partition.
- Press ‘L‘ to list all available types.
- Type ‘t‘to choose the partitions.
- Choose ‘fd‘ for Linux raid auto and press Enter to apply.
- Then again use ‘p‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Create Disk Partitions](http://www.tecmint.com/wp-content/uploads/2014/10/Create-Disk-Partitions.png)
Create Disk Partitions
After ‘/dev/sdb‘ partition has been created, next follow the same instructions to create new partition on /dev/sdc drive.
# fdisk /dev/sdc
![Create Second Partitions](http://www.tecmint.com/wp-content/uploads/2014/10/Create-Second-Partitions.png)
Create Second Partitions
4. Once both the partitions are created successfully, verify the changes on both sdb & sdc drive using the same ‘mdadm‘ command and also confirm the RAID type as shown in the following screen grabs.
# mdadm -E /dev/sd[b-c]
![Verify Partitions Changes](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-Partitions-Changes.png)
Verify Partitions Changes
![Check RAID Type](http://www.tecmint.com/wp-content/uploads/2014/10/Check-RAID-Type.png)
Check RAID Type
**Note**: As you see in the above picture, there is no any defined RAID on the sdb1 and sdc1 drives so far, that’s the reason we are getting as no super-blocks detected.
### Step 3: Creating RAID1 Devices ###
5. Next create RAID1 Device called ‘/dev/md0‘ using the following command and verity it.
# mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sd[b-c]1
# cat /proc/mdstat
![Create RAID Device](http://www.tecmint.com/wp-content/uploads/2014/10/Create-RAID-Device.png)
Create RAID Device
6. Next check the raid devices type and raid array using following commands.
# mdadm -E /dev/sd[b-c]1
# mdadm --detail /dev/md0
![Check RAID Device type](http://www.tecmint.com/wp-content/uploads/2014/10/Check-RAID-Device-type.png)
Check RAID Device type
![Check RAID Device Array](http://www.tecmint.com/wp-content/uploads/2014/10/Check-RAID-Device-Array.png)
Check RAID Device Array
From the above pictures, one can easily understand that raid1 have been created and using /dev/sdb1 and /dev/sdc1 partitions and also you can see the status as resyncing.
### Step 4: Creating File System on RAID Device ###
7. Create file system using ext4 for md0 and mount under /mnt/raid1.
# mkfs.ext4 /dev/md0
![Create RAID Device Filesystem](http://www.tecmint.com/wp-content/uploads/2014/10/Create-RAID-Device-Filesystem.png)
Create RAID Device Filesystem
8. Next, mount the newly created filesystem under ‘/mnt/raid1‘ and create some files and verify the contents under mount point.
# mkdir /mnt/raid1
# mount /dev/md0 /mnt/raid1/
# touch /mnt/raid1/tecmint.txt
# echo "tecmint raid setups" > /mnt/raid1/tecmint.txt
![Mount Raid Device](http://www.tecmint.com/wp-content/uploads/2014/10/Mount-RAID-Device.png)
Mount Raid Device
9. To auto-mount RAID1 on system reboot, you need to make an entry in fstab file. Open ‘/etc/fstab‘ file and add the following line at the bottom of the file.
/dev/md0 /mnt/raid1 ext4 defaults 0 0
![Raid Automount Device](http://www.tecmint.com/wp-content/uploads/2014/10/RAID-Automount-Filesystem.png)
Raid Automount Device
10. Run ‘mount -a‘ to check whether there are any errors in fstab entry.
# mount -av
![Check Errors in fstab](http://www.tecmint.com/wp-content/uploads/2014/10/Check-Errors-in-fstab.png)
Check Errors in fstab
11. Next, save the raid configuration manually to ‘mdadm.conf‘ file using the below command.
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
![Save Raid Configuration](http://www.tecmint.com/wp-content/uploads/2014/10/Save-Raid-Configuration.png)
Save Raid Configuration
The above configuration file is read by the system at the reboots and load the RAID devices.
### Step 5: Verify Data After Disk Failure ###
12. Our main purpose is, even after any of hard disk fail or crash our data needs to be available. Let’s see what will happen when any of disk disk is unavailable in array.
# mdadm --detail /dev/md0
![Raid Device Verify](http://www.tecmint.com/wp-content/uploads/2014/10/Raid-Device-Verify.png)
Raid Device Verify
In the above image, we can see there are 2 devices available in our RAID and Active Devices are 2. Now let us see what will happen when a disk plugged out (removed sdc disk) or fails.
# ls -l /dev | grep sd
# mdadm --detail /dev/md0
![Test RAID Devices](http://www.tecmint.com/wp-content/uploads/2014/10/Test-RAID-Devices.png)
Test RAID Devices
Now in the above image, you can see that one of our drive is lost. I unplugged one of the drive from my Virtual machine. Now let us check our precious data.
# cd /mnt/raid1/
# cat tecmint.txt
![Verify RAID Data](http://www.tecmint.com/wp-content/uploads/2014/10/Verify-RAID-Data.png)
Verify RAID Data
Did you see our data is still available. From this we come to know the advantage of RAID 1 (mirror). In next article, we will see how to setup a RAID 5 striping with distributed Parity. Hope this helps you to understand how the RAID 1 (Mirror) Works.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/create-raid1-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/
[1]:http://www.tecmint.com/understanding-raid-setup-in-linux/

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Creating RAID 5 (Striping with Distributed Parity) in Linux – Part 4
================================================================================
In RAID 5, data strips across multiple drives with distributed parity. The striping with distributed parity means it will split the parity information and stripe data over the multiple disks, which will have good data redundancy.
![Setup Raid 5 in CentOS](http://www.tecmint.com/wp-content/uploads/2014/11/setup-raid-5-in-linux.jpg)
Setup Raid 5 in Linux
For RAID Level it should have at least three hard drives or more. RAID 5 are being used in the large scale production environment where it’s cost effective and provide performance as well as redundancy.
#### What is Parity? ####
Parity is a simplest common method of detecting errors in data storage. Parity stores information in each disks, Let’s say we have 4 disks, in 4 disks one disk space will be split to all disks to store the parity information’s. If any one of the disks fails still we can get the data by rebuilding from parity information after replacing the failed disk.
#### Pros and Cons of RAID 5 ####
- Gives better performance
- Support Redundancy and Fault tolerance.
- Support hot spare options.
- Will loose a single disk capacity for using parity information.
- No data loss if a single disk fails. We can rebuilt from parity after replacing the failed disk.
- Suits for transaction oriented environment as the reading will be faster.
- Due to parity overhead, writing will be slow.
- Rebuild takes long time.
#### Requirements ####
Minimum 3 hard drives are required to create Raid 5, but you can add more disks, only if you’ve a dedicated hardware raid controller with multi ports. Here, we are using software RAID and ‘mdadm‘ package to create raid.
mdadm is a package which allow us to configure and manage RAID devices in Linux. By default there is no configuration file is available for RAID, we must save the configuration file after creating and configuring RAID setup in separate file called mdadm.conf.
Before moving further, I suggest you to go through the following articles for understanding the basics of RAID in Linux.
- [Basic Concepts of RAID in Linux – Part 1][1]
- [Creating RAID 0 (Stripe) in Linux – Part 2][2]
- [Setting up RAID 1 (Mirroring) in Linux – Part 3][3]
#### My Server Setup ####
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.227
Hostname : rd5.tecmintlocal.com
Disk 1 [20GB] : /dev/sdb
Disk 2 [20GB] : /dev/sdc
Disk 3 [20GB] : /dev/sdd
This article is a Part 4 of a 9-tutorial RAID series, here we are going to setup a software RAID 5 with distributed parity in Linux systems or servers using three 20GB disks named /dev/sdb, /dev/sdc and /dev/sdd.
### Step 1: Installing mdadm and Verify Drives ###
1. As we said earlier, that we’re using CentOS 6.5 Final release for this raid setup, but same steps can be followed for RAID setup in any Linux based distributions.
# lsb_release -a
# ifconfig | grep inet
![Setup Raid 5 in CentOS](http://www.tecmint.com/wp-content/uploads/2014/11/CentOS-6.5-Summary.png)
CentOS 6.5 Summary
2. If you’re following our raid series, we assume that you’ve already installed ‘mdadm‘ package, if not, use the following command according to your Linux distribution to install the package.
# yum install mdadm [on RedHat systems]
# apt-get install mdadm [on Debain systems]
3. After the ‘mdadm‘ package installation, let’s list the three 20GB disks which we have added in our system using ‘fdisk‘ command.
# fdisk -l | grep sd
![Install mdadm Tool in CentOS](http://www.tecmint.com/wp-content/uploads/2014/11/Install-mdadm-Tool.png)
Install mdadm Tool
4. Now it’s time to examine the attached three drives for any existing RAID blocks on these drives using following command.
# mdadm -E /dev/sd[b-d]
# mdadm --examine /dev/sdb /dev/sdc /dev/sdd
![Examine Drives For Raid](http://www.tecmint.com/wp-content/uploads/2014/11/Examine-Drives-For-Raid.png)
Examine Drives For Raid
**Note**: From the above image illustrated that there is no any super-block detected yet. So, there is no RAID defined in all three drives. Let us start to create one now.
### Step 2: Partitioning the Disks for RAID ###
5. First and foremost, we have to partition the disks (/dev/sdb, /dev/sdc and /dev/sdd) before adding to a RAID, So let us define the partition using ‘fdisk’ command, before forwarding to the next steps.
# fdisk /dev/sdb
# fdisk /dev/sdc
# fdisk /dev/sdd
#### Create /dev/sdb Partition ####
Please follow the below instructions to create partition on /dev/sdb drive.
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition. Here we are choosing Primary because there is no partitions defined yet.
- Then choose ‘1‘ to be the first partition. By default it will be 1.
- Here for cylinder size we don’t have to choose the specified size because we need the whole partition for RAID so just Press Enter two times to choose the default full size.
- Next press ‘p‘ to print the created partition.
- Change the Type, If we need to know the every available types Press ‘L‘.
- Here, we are selecting ‘fd‘ as my type is RAID.
- Next press ‘p‘ to print the defined partition.
- Then again use ‘p‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Create sdb Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdb-Partition1.png)
Create sdb Partition
**Note**: We have to follow the steps mentioned above to create partitions for sdc & sdd drives too.
#### Create /dev/sdc Partition ####
Now partition the sdc and sdd drives by following the steps given in the screenshot or you can follow above steps.
# fdisk /dev/sdc
![Create sdc Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdc-Partition1.png)
Create sdc Partition
#### Create /dev/sdd Partition ####
# fdisk /dev/sdd
![Create sdd Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdd-Partition1.png)
Create sdd Partition
6. After creating partitions, check for changes in all three drives sdb, sdc, & sdd.
# mdadm --examine /dev/sdb /dev/sdc /dev/sdd
or
# mdadm -E /dev/sd[b-c]
![Check Partition Changes](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Changes-on-Partitions.png)
Check Partition Changes
**Note**: In the above pic. depict the type is fd i.e. for RAID.
7. Now Check for the RAID blocks in newly created partitions. If no super-blocks detected, than we can move forward to create a new RAID 5 setup on these drives.
![Check Raid on Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-on-Partitions.png)
Check Raid on Partition
### Step 3: Creating md device md0 ###
8. Now create a Raid device ‘md0‘ (i.e. /dev/md0) and include raid level on all newly created partitions (sdb1, sdc1 and sdd1) using below command.
# mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1
or
# mdadm -C /dev/md0 -l=5 -n=3 /dev/sd[b-d]1
9. After creating raid device, check and verify the RAID, devices included and RAID Level from the mdstat output.
# cat /proc/mdstat
![Verify Raid Device](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Raid-Device.png)
Verify Raid Device
If you want to monitor the current building process, you can use ‘watch‘ command, just pass through the ‘cat /proc/mdstat‘ with watch command which will refresh screen every 1 second.
# watch -n1 cat /proc/mdstat
![Monitor Raid Process](http://www.tecmint.com/wp-content/uploads/2014/11/Monitor-Raid-Process.png)
Monitor Raid 5 Process
![Raid 5 Process Summary](http://www.tecmint.com/wp-content/uploads/2014/11/Raid-Process-Summary.png)
Raid 5 Process Summary
10. After creation of raid, Verify the raid devices using the following command.
# mdadm -E /dev/sd[b-d]1
![Verify Raid Level](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Raid-Level.png)
Verify Raid Level
**Note**: The Output of the above command will be little long as it prints the information of all three drives.
11. Next, verify the RAID array to assume that the devices which we’ve included in the RAID level are running and started to re-sync.
# mdadm --detail /dev/md0
![Verify Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Raid-Array.png)
Verify Raid Array
### Step 4: Creating file system for md0 ###
12. Create a file system for ‘md0‘ device using ext4 before mounting.
# mkfs.ext4 /dev/md0
![Create md0 Filesystem](http://www.tecmint.com/wp-content/uploads/2014/11/Create-md0-Filesystem.png)
Create md0 Filesystem
13. Now create a directory under ‘/mnt‘ then mount the created filesystem under /mnt/raid5 and check the files under mount point, you will see lost+found directory.
# mkdir /mnt/raid5
# mount /dev/md0 /mnt/raid5/
# ls -l /mnt/raid5/
14. Create few files under mount point /mnt/raid5 and append some text in any one of the file to verify the content.
# touch /mnt/raid5/raid5_tecmint_{1..5}
# ls -l /mnt/raid5/
# echo "tecmint raid setups" > /mnt/raid5/raid5_tecmint_1
# cat /mnt/raid5/raid5_tecmint_1
# cat /proc/mdstat
![Mount Raid 5 Device](http://www.tecmint.com/wp-content/uploads/2014/11/Mount-Raid-Device.png)
Mount Raid Device
15. We need to add entry in fstab, else will not display our mount point after system reboot. To add an entry, we should edit the fstab file and append the following line as shown below. The mount point will differ according to your environment.
# vim /etc/fstab
/dev/md0 /mnt/raid5 ext4 defaults 0 0
![Raid 5 Automount](http://www.tecmint.com/wp-content/uploads/2014/11/Raid-Device-Automount.png)
Raid 5 Automount
16. Next, run ‘mount -av‘ command to check whether any errors in fstab entry.
# mount -av
![Check Fstab Errors](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Fstab-Errors.png)
Check Fstab Errors
### Step 5: Save Raid 5 Configuration ###
17. As mentioned earlier in requirement section, by default RAID don’t have a config file. We have to save it manually. If this step is not followed RAID device will not be in md0, it will be in some other random number.
So, we must have to save the configuration before system reboot. If the configuration is saved it will be loaded to the kernel during the system reboot and RAID will also gets loaded.
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
![Save Raid 5 Configuration](http://www.tecmint.com/wp-content/uploads/2014/11/Save-Raid-5-Configuration.png)
Save Raid 5 Configuration
Note: Saving the configuration will keep the RAID level stable in md0 device.
### Step 6: Adding Spare Drives ###
18. What the use of adding a spare drive? its very useful if we have a spare drive, if any one of the disk fails in our array, this spare drive will get active and rebuild the process and sync the data from other disk, so we can see a redundancy here.
For more instructions on how to add spare drive and check Raid 5 fault tolerance, read #Step 6 and #Step 7 in the following article.
- [Add Spare Drive to Raid 5 Setup][4]
### Conclusion ###
Here, in this article, we have seen how to setup a RAID 5 using three number of disks. Later in my upcoming articles, we will see how to troubleshoot when a disk fails in RAID 5 and how to replace for recovery.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/create-raid-5-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/
[1]:http://www.tecmint.com/understanding-raid-setup-in-linux/
[2]:http://www.tecmint.com/create-raid0-in-linux/
[3]:http://www.tecmint.com/create-raid1-in-linux/
[4]:http://www.tecmint.com/create-raid-6-in-linux/

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Setup RAID Level 6 (Striping with Double Distributed Parity) in Linux – Part 5
================================================================================
RAID 6 is upgraded version of RAID 5, where it has two distributed parity which provides fault tolerance even after two drives fails. Mission critical system still operational incase of two concurrent disks failures. It’s alike RAID 5, but provides more robust, because it uses one more disk for parity.
In our earlier article, we’ve seen distributed parity in RAID 5, but in this article we will going to see RAID 6 with double distributed parity. Don’t expect extra performance than any other RAID, if so we have to install a dedicated RAID Controller too. Here in RAID 6 even if we loose our 2 disks we can get the data back by replacing a spare drive and build it from parity.
![Setup RAID 6 in CentOS](http://www.tecmint.com/wp-content/uploads/2014/11/Setup-RAID-6-in-Linux.jpg)
Setup RAID 6 in Linux
To setup a RAID 6, minimum 4 numbers of disks or more in a set are required. RAID 6 have multiple disks even in some set it may be have some bunch of disks, while reading, it will read from all the drives, so reading would be faster whereas writing would be poor because it has to stripe over multiple disks.
Now, many of us comes to conclusion, why we need to use RAID 6, when it doesn’t perform like any other RAID. Hmm… those who raise this question need to know that, if they need high fault tolerance choose RAID 6. In every higher environments with high availability for database, they use RAID 6 because database is the most important and need to be safe in any cost, also it can be useful for video streaming environments.
#### Pros and Cons of RAID 6 ####
- Performance are good.
- RAID 6 is expensive, as it requires two independent drives are used for parity functions.
- Will loose a two disks capacity for using parity information (double parity).
- No data loss, even after two disk fails. We can rebuilt from parity after replacing the failed disk.
- Reading will be better than RAID 5, because it reads from multiple disk, But writing performance will be very poor without dedicated RAID Controller.
#### Requirements ####
Minimum 4 numbers of disks are required to create a RAID 6. If you want to add more disks, you can, but you must have dedicated raid controller. In software RAID, we will won’t get better performance in RAID 6. So we need a physical RAID controller.
Those who are new to RAID setup, we recommend to go through RAID articles below.
- [Basic Concepts of RAID in Linux – Part 1][1]
- [Creating Software RAID 0 (Stripe) in Linux – Part 2][2]
- [Setting up RAID 1 (Mirroring) in Linux – Part 3][3]
#### My Server Setup ####
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.228
Hostname : rd6.tecmintlocal.com
Disk 1 [20GB] : /dev/sdb
Disk 2 [20GB] : /dev/sdc
Disk 3 [20GB] : /dev/sdd
Disk 4 [20GB] : /dev/sde
This article is a Part 5 of a 9-tutorial RAID series, here we are going to see how we can create and setup Software RAID 6 or Striping with Double Distributed Parity in Linux systems or servers using four 20GB disks named /dev/sdb, /dev/sdc, /dev/sdd and /dev/sde.
### Step 1: Installing mdadm Tool and Examine Drives ###
1. If you’re following our last two Raid articles (Part 2 and Part 3), where we’ve already shown how to install ‘mdadm‘ tool. If you’re new to this article, let me explain that ‘mdadm‘ is a tool to create and manage Raid in Linux systems, let’s install the tool using following command according to your Linux distribution.
# yum install mdadm [on RedHat systems]
# apt-get install mdadm [on Debain systems]
2. After installing the tool, now it’s time to verify the attached four drives that we are going to use for raid creation using the following ‘fdisk‘ command.
# fdisk -l | grep sd
![Check Hard Disk in Linux](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Linux-Disks.png)
Check Disks in Linux
3. Before creating a RAID drives, always examine our disk drives whether there is any RAID is already created on the disks.
# mdadm -E /dev/sd[b-e]
# mdadm --examine /dev/sdb /dev/sdc /dev/sdd /dev/sde
![Check Raid on Disk](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Disk-Raid.png)
Check Raid on Disk
**Note**: In the above image depicts that there is no any super-block detected or no RAID is defined in four disk drives. We may move further to start creating RAID 6.
### Step 2: Drive Partitioning for RAID 6 ###
4. Now create partitions for raid on ‘/dev/sdb‘, ‘/dev/sdc‘, ‘/dev/sdd‘ and ‘/dev/sde‘ with the help of following fdisk command. Here, we will show how to create partition on sdb drive and later same steps to be followed for rest of the drives.
**Create /dev/sdb Partition**
# fdisk /dev/sdb
Please follow the instructions as shown below for creating partition.
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition.
- Next choose the partition number as 1.
- Define the default value by just pressing two times Enter key.
- Next press ‘P‘ to print the defined partition.
- Press ‘L‘ to list all available types.
- Type ‘t‘ to choose the partitions.
- Choose ‘fd‘ for Linux raid auto and press Enter to apply.
- Then again use ‘P‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Create sdb Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdb-Partition.png)
Create /dev/sdb Partition
**Create /dev/sdb Partition**
# fdisk /dev/sdc
![Create sdc Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdc-Partition.png)
Create /dev/sdc Partition
**Create /dev/sdd Partition**
# fdisk /dev/sdd
![Create sdd Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sdd-Partition.png)
Create /dev/sdd Partition
**Create /dev/sde Partition**
# fdisk /dev/sde
![Create sde Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-sde-Partition.png)
Create /dev/sde Partition
5. After creating partitions, it’s always good habit to examine the drives for super-blocks. If super-blocks does not exist than we can go head to create a new RAID setup.
# mdadm -E /dev/sd[b-e]1
or
# mdadm --examine /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
![Check Raid on New Partitions](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-on-New-Partitions.png)
Check Raid on New Partitions
### Step 3: Creating md device (RAID) ###
6. Now it’s time to create Raid device ‘md0‘ (i.e. /dev/md0) and apply raid level on all newly created partitions and confirm the raid using following commands.
# mdadm --create /dev/md0 --level=6 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
# cat /proc/mdstat
![Create Raid 6 Device](http://www.tecmint.com/wp-content/uploads/2014/11/Create-Raid-6-Device.png)
Create Raid 6 Device
7. You can also check the current process of raid using watch command as shown in the screen grab below.
# watch -n1 cat /proc/mdstat
![Check Raid 6 Process](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-6-Process.png)
Check Raid 6 Process
8. Verify the raid devices using the following command.
# mdadm -E /dev/sd[b-e]1
**Note**:: The above command will be display the information of the four disks, which is quite long so not possible to post the output or screen grab here.
9. Next, verify the RAID array to confirm that the re-syncing is started.
# mdadm --detail /dev/md0
![Check Raid 6 Array](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-6-Array.png)
Check Raid 6 Array
### Step 4: Creating FileSystem on Raid Device ###
10. Create a filesystem using ext4 for ‘/dev/md0‘ and mount it under /mnt/raid5. Here we’ve used ext4, but you can use any type of filesystem as per your choice.
# mkfs.ext4 /dev/md0
![Create File System on Raid](http://www.tecmint.com/wp-content/uploads/2014/11/Create-File-System-on-Raid.png)
Create File System on Raid 6
11. Mount the created filesystem under /mnt/raid6 and verify the files under mount point, we can see lost+found directory.
# mkdir /mnt/raid6
# mount /dev/md0 /mnt/raid6/
# ls -l /mnt/raid6/
12. Create some files under mount point and append some text in any one of the file to verify the content.
# touch /mnt/raid6/raid6_test.txt
# ls -l /mnt/raid6/
# echo "tecmint raid setups" > /mnt/raid6/raid6_test.txt
# cat /mnt/raid6/raid6_test.txt
![Verify Raid Content](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Raid-Content.png)
Verify Raid Content
13. Add an entry in /etc/fstab to auto mount the device at the system startup and append the below entry, mount point may differ according to your environment.
# vim /etc/fstab
/dev/md0 /mnt/raid6 ext4 defaults 0 0
![Automount Raid 6 Device](http://www.tecmint.com/wp-content/uploads/2014/11/Automount-Raid-Device.png)
Automount Raid 6 Device
14. Next, execute ‘mount -a‘ command to verify whether there is any error in fstab entry.
# mount -av
![Verify Raid Automount](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Automount-Raid-Devices.png)
Verify Raid Automount
### Step 5: Save RAID 6 Configuration ###
15. Please note by default RAID don’t have a config file. We have to save it by manually using below command and then verify the status of device ‘/dev/md0‘.
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
# mdadm --detail /dev/md0
![Save Raid 6 Configuration](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-Status.png)
Save Raid 6 Configuration
![Check Raid 6 Status](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-Status.png)
Check Raid 6 Status
### Step 6: Adding a Spare Drives ###
16. Now it has 4 disks and there are two parity information’s available. In some cases, if any one of the disk fails we can get the data, because there is double parity in RAID 6.
May be if the second disk fails, we can add a new one before loosing third disk. It is possible to add a spare drive while creating our RAID set, But I have not defined the spare drive while creating our raid set. But, we can add a spare drive after any drive failure or while creating the RAID set. Now we have already created the RAID set now let me add a spare drive for demonstration.
For the demonstration purpose, I’ve hot-plugged a new HDD disk (i.e. /dev/sdf), let’s verify the attached disk.
# ls -l /dev/ | grep sd
![Check New Disk](http://www.tecmint.com/wp-content/uploads/2014/11/Check-New-Disk.png)
Check New Disk
17. Now again confirm the new attached disk for any raid is already configured or not using the same mdadm command.
# mdadm --examine /dev/sdf
![Check Raid on New Disk](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-on-New-Disk.png)
Check Raid on New Disk
**Note**: As usual, like we’ve created partitions for four disks earlier, similarly we’ve to create new partition on the new plugged disk using fdisk command.
# fdisk /dev/sdf
![Create sdf Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Create-Partition-on-sdf.png)
Create /dev/sdf Partition
18. Again after creating new partition on /dev/sdf, confirm the raid on the partition, include the spare drive to the /dev/md0 raid device and verify the added device.
# mdadm --examine /dev/sdf
# mdadm --examine /dev/sdf1
# mdadm --add /dev/md0 /dev/sdf1
# mdadm --detail /dev/md0
![Verify Raid on sdf Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-Raid-on-sdf.png)
Verify Raid on sdf Partition
![Add sdf Partition to Raid](http://www.tecmint.com/wp-content/uploads/2014/11/Add-sdf-Partition-to-Raid.png)
Add sdf Partition to Raid
![Verify sdf Partition Details](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-sdf-Details.png)
Verify sdf Partition Details
### Step 7: Check Raid 6 Fault Tolerance ###
19. Now, let us check whether spare drive works automatically, if anyone of the disk fails in our Array. For testing, I’ve personally marked one of the drive is failed.
Here, we’re going to mark /dev/sdd1 as failed drive.
# mdadm --manage --fail /dev/md0 /dev/sdd1
![Check Raid 6 Fault Tolerance](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-6-Failover.png)
Check Raid 6 Fault Tolerance
20. Let me get the details of RAID set now and check whether our spare started to sync.
# mdadm --detail /dev/md0
![Check Auto Raid Syncing](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Auto-Raid-Syncing.png)
Check Auto Raid Syncing
**Hurray!** Here, we can see the spare got activated and started rebuilding process. At the bottom we can see the faulty drive /dev/sdd1 listed as faulty. We can monitor build process using following command.
# cat /proc/mdstat
![Raid 6 Auto Syncing](http://www.tecmint.com/wp-content/uploads/2014/11/Raid-6-Auto-Syncing.png)
Raid 6 Auto Syncing
### Conclusion: ###
Here, we have seen how to setup RAID 6 using four disks. This RAID level is one of the expensive setup with high redundancy. We will see how to setup a Nested RAID 10 and much more in the next articles. Till then, stay connected with TECMINT.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/create-raid-6-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/
[1]:http://www.tecmint.com/understanding-raid-setup-in-linux/
[2]:http://www.tecmint.com/create-raid0-in-linux/
[3]:http://www.tecmint.com/create-raid1-in-linux/

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struggling 翻译中
Setting Up RAID 10 or 1+0 (Nested) in Linux – Part 6
================================================================================
RAID 10 is a combine of RAID 0 and RAID 1 to form a RAID 10. To setup Raid 10, we need at least 4 number of disks. In our earlier articles, we’ve seen how to setup a RAID 0 and RAID 1 with minimum 2 number of disks.
Here we will use both RAID 0 and RAID 1 to perform a Raid 10 setup with minimum of 4 drives. Assume, that we’ve some data saved to logical volume, which is created with RAID 10. Just for an example, if we are saving a data “apple” this will be saved under all 4 disk by this following method.
![Create Raid 10 in Linux](http://www.tecmint.com/wp-content/uploads/2014/11/raid10.jpg)
Create Raid 10 in Linux
Using RAID 0 it will save as “A” in first disk and “p” in the second disk, then again “p” in first disk and “l” in second disk. Then “e” in first disk, like this it will continue the Round robin process to save the data. From this we come to know that RAID 0 will write the half of the data to first disk and other half of the data to second disk.
In RAID 1 method, same data will be written to other 2 disks as follows. “A” will write to both first and second disks, “P” will write to both disk, Again other “P” will write to both the disks. Thus using RAID 1 it will write to both the disks. This will continue in round robin process.
Now you all came to know that how RAID 10 works by combining of both RAID 0 and RAID 1. If we have 4 number of 20 GB size disks, it will be 80 GB in total, but we will get only 40 GB of Storage capacity, the half of total capacity will be lost for building RAID 10.
#### Pros and Cons of RAID 5 ####
- Gives better performance.
- We will loose two of the disk capacity in RAID 10.
- Reading and writing will be very good, because it will write and read to all those 4 disk at the same time.
- It can be used for Database solutions, which needs a high I/O disk writes.
#### Requirements ####
In RAID 10, we need minimum of 4 disks, the first 2 disks for RAID 0 and other 2 Disks for RAID 1. Like I said before, RAID 10 is just a Combine of RAID 0 & 1. If we need to extended the RAID group, we must increase the disk by minimum 4 disks.
**My Server Setup**
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.229
Hostname : rd10.tecmintlocal.com
Disk 1 [20GB] : /dev/sdd
Disk 2 [20GB] : /dev/sdc
Disk 3 [20GB] : /dev/sdd
Disk 4 [20GB] : /dev/sde
There are two ways to setup RAID 10, but here I’m going to show you both methods, but I prefer you to follow the first method, which makes the work lot easier for setting up a RAID 10.
### Method 1: Setting Up Raid 10 ###
1. First, verify that all the 4 added disks are detected or not using the following command.
# ls -l /dev | grep sd
2. Once the four disks are detected, it’s time to check for the drives whether there is already any raid existed before creating a new one.
# mdadm -E /dev/sd[b-e]
# mdadm --examine /dev/sdb /dev/sdc /dev/sdd /dev/sde
![Verify 4 Added Disks](http://www.tecmint.com/wp-content/uploads/2014/11/Verify-4-Added-Disks.png)
Verify 4 Added Disks
**Note**: In the above output, you see there isn’t any super-block detected yet, that means there is no RAID defined in all 4 drives.
#### Step 1: Drive Partitioning for RAID ####
3. Now create a new partition on all 4 disks (/dev/sdb, /dev/sdc, /dev/sdd and /dev/sde) using the ‘fdisk’ tool.
# fdisk /dev/sdb
# fdisk /dev/sdc
# fdisk /dev/sdd
# fdisk /dev/sde
**Create /dev/sdb Partition**
Let me show you how to partition one of the disk (/dev/sdb) using fdisk, this steps will be the same for all the other disks too.
# fdisk /dev/sdb
Please use the below steps for creating a new partition on /dev/sdb drive.
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition.
- Then choose ‘1‘ to be the first partition.
- Next press ‘p‘ to print the created partition.
- Change the Type, If we need to know the every available types Press ‘L‘.
- Here, we are selecting ‘fd‘ as my type is RAID.
- Next press ‘p‘ to print the defined partition.
- Then again use ‘p‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Disk sdb Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Disk-sdb-Partition.png)
Disk sdb Partition
**Note**: Please use the above same instructions for creating partitions on other disks (sdc, sdd sdd sde).
4. After creating all 4 partitions, again you need to examine the drives for any already existing raid using the following command.
# mdadm -E /dev/sd[b-e]
# mdadm -E /dev/sd[b-e]1
OR
# mdadm --examine /dev/sdb /dev/sdc /dev/sdd /dev/sde
# mdadm --examine /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
![Check All Disks for Raid](http://www.tecmint.com/wp-content/uploads/2014/11/Check-All-Disks-for-Raid.png)
Check All Disks for Raid
**Note**: The above outputs shows that there isn’t any super-block detected on all four newly created partitions, that means we can move forward to create RAID 10 on these drives.
#### Step 2: Creating ‘md’ RAID Device ####
5. Now it’s time to create a ‘md’ (i.e. /dev/md0) device, using ‘mdadm’ raid management tool. Before, creating device, your system must have ‘mdadm’ tool installed, if not install it first.
# yum install mdadm [on RedHat systems]
# apt-get install mdadm [on Debain systems]
Once ‘mdadm’ tool installed, you can now create a ‘md’ raid device using the following command.
# mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/sd[b-e]1
6. Next verify the newly created raid device using the ‘cat’ command.
# cat /proc/mdstat
![Create md raid Device](http://www.tecmint.com/wp-content/uploads/2014/11/Create-md-raid-Device.png)
Create md raid Device
7. Next, examine all the 4 drives using the below command. The output of the below command will be long as it displays the information of all 4 disks.
# mdadm --examine /dev/sd[b-e]1
8. Next, check the details of Raid Array with the help of following command.
# mdadm --detail /dev/md0
![Check Raid Array Details](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-Array-Details.png)
Check Raid Array Details
**Note**: You see in the above results, that the status of Raid was active and re-syncing.
#### Step 3: Creating Filesystem ####
9. Create a file system using ext4 for ‘md0′ and mount it under ‘/mnt/raid10‘. Here, I’ve used ext4, but you can use any filesystem type if you want.
# mkfs.ext4 /dev/md0
![Create md Filesystem](http://www.tecmint.com/wp-content/uploads/2014/11/Create-md-Filesystem.png)
Create md Filesystem
10. After creating filesystem, mount the created file-system under ‘/mnt/raid10‘ and list the contents of the mount point using ‘ls -l’ command.
# mkdir /mnt/raid10
# mount /dev/md0 /mnt/raid10/
# ls -l /mnt/raid10/
Next, add some files under mount point and append some text in any one of the file and check the content.
# touch /mnt/raid10/raid10_files.txt
# ls -l /mnt/raid10/
# echo "raid 10 setup with 4 disks" > /mnt/raid10/raid10_files.txt
# cat /mnt/raid10/raid10_files.txt
![Mount md Device](http://www.tecmint.com/wp-content/uploads/2014/11/Mount-md-Device.png)
Mount md Device
11. For automounting, open the ‘/etc/fstab‘ file and append the below entry in fstab, may be mount point will differ according to your environment. Save and quit using wq!.
# vim /etc/fstab
/dev/md0 /mnt/raid10 ext4 defaults 0 0
![AutoMount md Device](http://www.tecmint.com/wp-content/uploads/2014/11/AutoMount-md-Device.png)
AutoMount md Device
12. Next, verify the ‘/etc/fstab‘ file for any errors before restarting the system using ‘mount -a‘ command.
# mount -av
![Check Errors in Fstab](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Errors-in-Fstab.png)
Check Errors in Fstab
#### Step 4: Save RAID Configuration ####
13. By default RAID don’t have a config file, so we need to save it manually after making all the above steps, to preserve these settings during system boot.
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
![Save Raid10 Configuration](http://www.tecmint.com/wp-content/uploads/2014/11/Save-Raid10-Configuration.png)
Save Raid10 Configuration
That’s it, we have created RAID 10 using method 1, this method is the easier one. Now let’s move forward to setup RAID 10 using method 2.
### Method 2: Creating RAID 10 ###
1. In method 2, we have to define 2 sets of RAID 1 and then we need to define a RAID 0 using those created RAID 1 sets. Here, what we will do is to first create 2 mirrors (RAID1) and then striping over RAID0.
First, list the disks which are all available for creating RAID 10.
# ls -l /dev | grep sd
![List 4 Devices](http://www.tecmint.com/wp-content/uploads/2014/11/List-4-Devices.png)
List 4 Devices
2. Partition the all 4 disks using ‘fdisk’ command. For partitioning, you can follow #step 3 above.
# fdisk /dev/sdb
# fdisk /dev/sdc
# fdisk /dev/sdd
# fdisk /dev/sde
3. After partitioning all 4 disks, now examine the disks for any existing raid blocks.
# mdadm --examine /dev/sd[b-e]
# mdadm --examine /dev/sd[b-e]1
![Examine 4 Disks](http://www.tecmint.com/wp-content/uploads/2014/11/Examine-4-Disks.png)
Examine 4 Disks
#### Step 1: Creating RAID 1 ####
4. First let me create 2 sets of RAID 1 using 4 disks ‘sdb1′ and ‘sdc1′ and other set using ‘sdd1′ & ‘sde1′.
# mdadm --create /dev/md1 --metadata=1.2 --level=1 --raid-devices=2 /dev/sd[b-c]1
# mdadm --create /dev/md2 --metadata=1.2 --level=1 --raid-devices=2 /dev/sd[d-e]1
# cat /proc/mdstat
![Creating Raid 1](http://www.tecmint.com/wp-content/uploads/2014/11/Creating-Raid-1.png)
Creating Raid 1
![Check Details of Raid 1](http://www.tecmint.com/wp-content/uploads/2014/11/Creating-Raid-1.png)
Check Details of Raid 1
#### Step 2: Creating RAID 0 ####
5. Next, create the RAID 0 using md1 and md2 devices.
# mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/md1 /dev/md2
# cat /proc/mdstat
![Creating Raid 0](http://www.tecmint.com/wp-content/uploads/2014/11/Creating-Raid-0.png)
Creating Raid 0
#### Step 3: Save RAID Configuration ####
6. We need to save the Configuration under ‘/etc/mdadm.conf‘ to load all raid devices in every reboot times.
# mdadm --detail --scan --verbose >> /etc/mdadm.conf
After this, we need to follow #step 3 Creating file system of method 1.
That’s it! we have created RAID 1+0 using method 2. We will loose two disks space here, but the performance will be excellent compared to any other raid setups.
### Conclusion ###
Here we have created RAID 10 using two methods. RAID 10 has good performance and redundancy too. Hope this helps you to understand about RAID 10 Nested Raid level. Let us see how to grow an existing raid array and much more in my upcoming articles.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/create-raid-10-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/

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struggling 翻译中
Growing an Existing RAID Array and Removing Failed Disks in Raid – Part 7
================================================================================
Every newbies will get confuse of the word array. Array is just a collection of disks. In other words, we can call array as a set or group. Just like a set of eggs containing 6 numbers. Likewise RAID Array contains number of disks, it may be 2, 4, 6, 8, 12, 16 etc. Hope now you know what Array is.
Here we will see how to grow (extend) an existing array or raid group. For example, if we are using 2 disks in an array to form a raid 1 set, and in some situation if we need more space in that group, we can extend the size of an array using mdadm –grow command, just by adding one of the disk to the existing array. After growing (adding disk to an existing array), we will see how to remove one of the failed disk from array.
![Grow Raid Array in Linux](http://www.tecmint.com/wp-content/uploads/2014/11/Growing-Raid-Array.jpg)
Growing Raid Array and Removing Failed Disks
Assume that one of the disk is little weak and need to remove that disk, till it fails let it under use, but we need to add one of the spare drive and grow the mirror before it fails, because we need to save our data. While the weak disk fails we can remove it from array this is the concept we are going to see in this topic.
#### Features of RAID Growth ####
- We can grow (extend) the size of any raid set.
- We can remove the faulty disk after growing raid array with new disk.
- We can grow raid array without any downtime.
Requirements
- To grow an RAID array, we need an existing RAID set (Array).
- We need extra disks to grow the Array.
- Here I’m using 1 disk to grow the existing array.
Before we learn about growing and recovering of Array, we have to know about the basics of RAID levels and setups. Follow the below links to know about those setups.
- [Understanding Basic RAID Concepts – Part 1][1]
- [Creating a Software Raid 0 in Linux – Part 2][2]
#### My Server Setup ####
Operating System : CentOS 6.5 Final
IP Address : 192.168.0.230
Hostname : grow.tecmintlocal.com
2 Existing Disks : 1 GB
1 Additional Disk : 1 GB
Here, my already existing RAID has 2 number of disks with each size is 1GB and we are now adding one more disk whose size is 1GB to our existing raid array.
### Growing an Existing RAID Array ###
1. Before growing an array, first list the existing Raid array using the following command.
# mdadm --detail /dev/md0
![Check Existing Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Existing-Raid-Array.png)
Check Existing Raid Array
**Note**: The above output shows that I’ve already has two disks in Raid array with raid1 level. Now here we are adding one more disk to an existing array,
2. Now let’s add the new disk “sdd” and create a partition using ‘fdisk‘ command.
# fdisk /dev/sdd
Please use the below instructions to create a partition on /dev/sdd drive.
- Press ‘n‘ for creating new partition.
- Then choose ‘P‘ for Primary partition.
- Then choose ‘1‘ to be the first partition.
- Next press ‘p‘ to print the created partition.
- Here, we are selecting ‘fd‘ as my type is RAID.
- Next press ‘p‘ to print the defined partition.
- Then again use ‘p‘ to print the changes what we have made.
- Use ‘w‘ to write the changes.
![Create New Partition in Linux](http://www.tecmint.com/wp-content/uploads/2014/11/Create-New-sdd-Partition.png)
Create New sdd Partition
3. Once new sdd partition created, you can verify it using below command.
# ls -l /dev/ | grep sd
![Confirm sdd Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Confirm-sdd-Partition.png)
Confirm sdd Partition
4. Next, examine the newly created disk for any existing raid, before adding to the array.
# mdadm --examine /dev/sdd1
![Check Raid on sdd Partition](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Raid-on-sdd-Partition.png)
Check Raid on sdd Partition
**Note**: The above output shows that the disk has no super-blocks detected, means we can move forward to add a new disk to an existing array.
4. To add the new partition /dev/sdd1 in existing array md0, use the following command.
# mdadm --manage /dev/md0 --add /dev/sdd1
![Add Disk To Raid-Array](http://www.tecmint.com/wp-content/uploads/2014/11/Add-Disk-To-Raid-Array.png)
Add Disk To Raid-Array
5. Once the new disk has been added, check for the added disk in our array using.
# mdadm --detail /dev/md0
![Confirm Disk Added to Raid](http://www.tecmint.com/wp-content/uploads/2014/11/Confirm-Disk-Added-To-Raid.png)
Confirm Disk Added to Raid
**Note**: In the above output, you can see the drive has been added as a spare. Here, we already having 2 disks in the array, but what we are expecting is 3 devices in array for that we need to grow the array.
6. To grow the array we have to use the below command.
# mdadm --grow --raid-devices=3 /dev/md0
![Grow Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Grow-Raid-Array.png)
Grow Raid Array
Now we can see the third disk (sdd1) has been added to array, after adding third disk it will sync the data from other two disks.
# mdadm --detail /dev/md0
![Confirm Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Confirm-Raid-Array.png)
Confirm Raid Array
**Note**: For large size disk it will take hours to sync the contents. Here I have used 1GB virtual disk, so its done very quickly within seconds.
### Removing Disks from Array ###
7. After the data has been synced to new disk ‘sdd1‘ from other two disks, that means all three disks now have same contents.
As I told earlier let’s assume that one of the disk is weak and needs to be removed, before it fails. So, now assume disk ‘sdc1‘ is weak and needs to be removed from an existing array.
Before removing a disk we have to mark the disk as failed one, then only we can able to remove it.
# mdadm --fail /dev/md0 /dev/sdc1
# mdadm --detail /dev/md0
![Disk Fail in Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Disk-Fail-in-Raid-Array.png)
Disk Fail in Raid Array
From the above output, we clearly see that the disk was marked as faulty at the bottom. Even its faulty, we can see the raid devices are 3, failed 1 and state was degraded.
Now we have to remove the faulty drive from the array and grow the array with 2 devices, so that the raid devices will be set to 2 devices as before.
# mdadm --remove /dev/md0 /dev/sdc1
![Remove Disk in Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Remove-Disk-in-Raid-Array.png)
Remove Disk in Raid Array
8. Once the faulty drive is removed, now we’ve to grow the raid array using 2 disks.
# mdadm --grow --raid-devices=2 /dev/md0
# mdadm --detail /dev/md0
![Grow Disks in Raid Array](http://www.tecmint.com/wp-content/uploads/2014/11/Grow-Disks-in-Raid-Array.png)
Grow Disks in Raid Array
From the about output, you can see that our array having only 2 devices. If you need to grow the array again, follow the same steps as described above. If you need to add a drive as spare, mark it as spare so that if the disk fails, it will automatically active and rebuild.
### Conclusion ###
In the article, we’ve seen how to grow an existing raid set and how to remove a faulty disk from an array after re-syncing the existing contents. All these steps can be done without any downtime. During data syncing, system users, files and applications will not get affected in any case.
In next, article I will show you how to manage the RAID, till then stay tuned to updates and don’t forget to add your comments.
--------------------------------------------------------------------------------
via: http://www.tecmint.com/grow-raid-array-in-linux/
作者：[Babin Lonston][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](https://linux.cn/) 荣誉推出
[a]:http://www.tecmint.com/author/babinlonston/
[1]:http://www.tecmint.com/understanding-raid-setup-in-linux/
[2]:http://www.tecmint.com/create-raid0-in-linux/

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XLCYun translating.
How To Fix System Program Problem Detected In Ubuntu 14.04
================================================================================
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/07/system_program_Problem_detected.jpeg)
@ -79,4 +82,4 @@ via: http://itsfoss.com/how-to-fix-system-program-problem-detected-ubuntu/
[a]:http://itsfoss.com/author/abhishek/
[1]:http://itsfoss.com/how-to-solve-sorry-ubuntu-12-04-has-experienced-an-internal-error/
[2]:https://launchpad.net/
[2]:https://launchpad.net/

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使用去重加密工具来备份
================================================================================
在体积和价值方面，数据都在增长。快速而可靠地备份和恢复数据正变得越来越重要。社会已经适应了技术的广泛使用，并懂得了如何依靠电脑和移动设备，但很少有人能够处理丢失重要数据的现实。在遭受数据损失的公司中，30% 的公司将在一年内损失一半市值，70% 的公司将在五年内停止交易。这更加凸显了数据的价值。
随着数据在体积上的增长，提高存储利用率尤为重要。In Computing(注:这里不知如何翻译)，数据去重是一种特别的数据压缩技术，因为它可以消除重复数据的拷贝，所以这个技术可以提高存储利用率。
数据并不仅仅只有其创造者感兴趣。政府、竞争者、犯罪分子、偷窥者可能都热衷于获取你的数据。他们或许想偷取你的数据，从你那里进行敲诈，或看你正在做什么。对于保护你的数据，加密是非常必要的。
所以，解决方法是我们需要一个去重加密备份软件。
对于所有的用户而言，做文件备份是一件非常必要的事，至今为止许多用户还没有采取足够的措施来保护他们的数据。一台电脑不论是工作在一个合作的环境中，还是供私人使用，机器的硬盘可能在没有任何警告的情况下挂掉。另外，有些数据丢失可能是人为的错误所引发的。如果没有做经常性的备份，数据也可能不可避免地失去掉，即使请了专业的数据恢复公司来帮忙。
这篇文章将对 6 个去重加密备份工具进行简要的介绍。
----------
### Attic ###
Attic 是一个可用于去重、加密，验证完整性的用 Python 写的压缩备份程序。Attic 的主要目标是提供一个高效且安全的方式来备份数据。Attic 使用的数据去重技术使得它适用于每日备份，因为只需存储改变的数据。
其特点有:
- 易用
- 可高效利用存储空间，通过检查冗余的数据，数据块大小的去重被用来减少存储所用的空间
- 可选的数据加密，使用 256 位的 AES 加密算法。数据的完整性和可靠性使用 HMAC-SHA256 来检查
- 使用 SDSH 来进行离线备份
- 备份可作为文件系统来挂载
网站: [attic-backup.org][1]
----------
### Borg ###
Borg 是 Attic 的分支。它是一个安全的开源备份程序，被设计用来高效地存储那些新的或修改过的数据。
Borg 的主要目标是提供一个高效、安全的方式来存储数据。Borg 使用的数据去重技术使得它适用于每日备份，因为只需存储改变的数据。认证加密使得它适用于不完全可信的目标的存储。
Borg 由 Python 写成。Borg 于 2015 年 5 月被创造出来，为了回应让新的代码或重大的改变带入 Attic 的困难。
其特点包括:
- 易用
- 可高效利用存储空间，通过检查冗余的数据，数据块大小的去重被用来减少存储所用的空间
- 可选的数据加密，使用 256 位的 AES 加密算法。数据的完整性和可靠性使用 HMAC-SHA256 来检查
- 使用 SDSH 来进行离线备份
- 备份可作为文件系统来挂载
Borg 与 Attic 不兼容。
网站: [borgbackup.github.io/borgbackup][2]
----------
### Obnam ###
Obnam (OBligatory NAMe) 是一个易用、安全的基于 Python 的备份程序。备份可被存储在本地硬盘或通过 SSH SFTP 协议存储到网上。若使用了备份服务器，它并不需要任何特殊的软件，只需要使用 SSH 即可。
Obnam 通过将数据数据分成数据块，并单独存储它们来达到去重的目的，每次通过增量备份来生成备份，每次备份的生成就像是一次新的快照，但事实上是真正的增量备份。Obnam 由 Lars Wirzenius 开发。
其特点有:
- 易用
- 快照备份
- 数据去重，跨文件，生成备份
- 可使用 GnuPG 来加密备份
- 向一个单独的仓库中备份多个客户端的数据
- 备份检查点 (创建一个保存点，以每 100MB 或其他容量)
- 包含多个选项来调整性能，包括调整 lru-size 或 upload-queue-size
- 支持 MD5 校验和算法来识别重复的数据块
- 通过 SFTP 将备份存储到一个服务器上
- 同时支持 push(即在客户端上运行) 和 pull(即在服务器上运行)
网站: [obnam.org][3]
----------
### Duplicity ###
Duplicity 持续地以 tar 文件格式备份文件和目录，并使用 GnuPG 来进行加密，同时将它们上传到远程(或本地)的文件服务器上。它可以使用 ssh/scp, 本地文件获取, rsync, ftp, 和 Amazon S3 等来传递数据。
因为 duplicity 使用了 librsync， 增加的存档高效地利用了存储空间，且只记录自从上次备份依赖改变的那部分文件。由于该软件使用 GnuPG 来机密或对这些归档文件进行进行签名，这使得它们免于服务器的监视或修改。
当前 duplicity 支持备份删除的文件，全部的 unix 权限，目录，符号链接， fifo 等。
duplicity 软件包还包含有 rdiffdir 工具。 Rdiffdir 是 librsync 的 rdiff 针对目录的扩展。它可以用来生成对目录的签名和差异，对普通文件也有效。
其特点有:
- 使用简单
- 对归档进行加密和签名(使用 GnuPG)
- 高效使用带宽和存储空间，使用 rsync 的算法
- 标准的文件格式
- 可选择多种远程协议
- 本地存储
- scp/ssh
- ftp
- rsync
- HSI
- WebDAV
- Amazon S3
网站: [duplicity.nongnu.org][4]
----------
### ZBackup ###
ZBackup 是一个通用的全局去重备份工具。
其特点包括:
- 存储数据的并行 LZMA 或 LZO 压缩，在一个仓库中，你还可以混合使用 LZMA 和 LZO
- 内置对存储数据的 AES 加密
- 可选择地删除旧的备份数据
- 可以使用 64 位的滚动哈希算法，使得文件冲突的数量几乎为零
- Repository consists of immutable files. No existing files are ever modified ====
- 用 C++ 写成，只需少量的库文件依赖
- 在生成环境中可以安全使用
- 可以在不同仓库中进行数据交换而不必再进行压缩
- 可以使用 64 位改进型 Rabin-Karp 滚动哈希算法
网站: [zbackup.org][5]
----------
### bup ###
bup 是一个用 Python 写的备份程序，其名称是 "backup" 的缩写。在 git packfile 文件的基础上， bup 提供了一个高效的方式来备份一个系统，提供快速的增量备份和全局去重(在文件中或文件里，甚至包括虚拟机镜像)。
bup 在 LGPL 版本 2 协议下发行。
其特点包括:
- 全局去重 (在文件中或文件里，甚至包括虚拟机镜像)
- 使用一个滚动的校验和算法(类似于 rsync) 来将大文件分为多个数据块
- 使用来自 git 的 packfile 格式
- 直接写入 packfile 文件，以此提供快速的增量备份
- 可以使用 "par2" 冗余来恢复冲突的备份
- 可以作为一个 FUSE 文件系统来挂载你的 bup 仓库
网站: [bup.github.io][6]
--------------------------------------------------------------------------------
via: http://www.linuxlinks.com/article/20150628060000607/BackupTools.html
译者：[FSSlc](https://github.com/FSSlc)
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](https://linux.cn/) 荣誉推出
[1]:https://attic-backup.org/
[2]:https://borgbackup.github.io/borgbackup/
[3]:http://obnam.org/
[4]:http://duplicity.nongnu.org/
[5]:http://zbackup.org/
[6]:https://bup.github.io/

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为什么mysql里的ibdata1文件不断的增长？
================================================================================
![ibdata1 file](https://www.percona.com/blog/wp-content/uploads/2013/08/ibdata1-file.jpg)
我们在[Percona支持][1]经常收到关于MySQL的ibdata1文件的这个问题。
当监控服务器发送一个关于MySQL服务器存储的报警恐慌就开始了 - 就是说磁盘快要满了。
一番调查后你意识到大多数地盘空间被InnDB的共享表空间ibdata1使用。你已经启用了[innodb_file_per_table][2]，所以问题是：
### ibdata1存了什么？ ###
当你启用了innodb_file_per_table，表被存储在他们自己的表空间里，但是共享表空间仍然在存储其他InnoDB的内部数据：
- 数据字典也就是InnoDB表的元数据
- 交换缓冲区
- 双写缓冲区
- 撤销日志
在[Percona服务器][3]上有一些是可以被配置来避免增长过大的。例如你可以通过[innodb_ibuf_max_size][4]设置最大交换缓冲区或设置[innodb_doublewrite_file][5]存储双写缓冲区到一个分离的文件。
MySQL 5.6版中你也可以创建额外的撤销表空间所以他们将会有他们自己的文件来替代存储到ibdata1。照着[文档链接][6]检查。
### 什么引起ibdata1增长迅速？ ###
当MySQL出现问题通常我们需要执行的第一个命令是：
SHOW ENGINE INNODB STATUSG（这里我觉得应该是STATUS/G）
这将展示给我们一些很有价值的信息。我们开始检查**事务**部分，然后我们会发现这个：
---TRANSACTION 36E, ACTIVE 1256288 sec
MySQL thread id 42, OS thread handle 0x7f8baaccc700, query id 7900290 localhost root
show engine innodb status
Trx read view will not see trx with id >= 36F, sees < 36F
这是一个最常见的原因，一个14天前创建的相当老的老事务。这个状态是**活动的**，这意味着InnoDB已经创建了一个快照数据，所以需要在**撤销**日志中维护旧页面，以保障数据库的一致性视图，直到事务开始。如果你的数据库是写负载大，那就意味着大量的撤销页已经被存储了。
如果你找不到任何长时间运行的事务，你也可以监控INNODB状态中的其他的变量，“**历史记录列表长度**”展示了一些等待清除操作。这种情况下问题经常发生，因为清除线程（或者老版本的主线程）不能以这些记录进来的速度处理撤销。
### 我怎么检查什么被存储到了ibdata1里了？ ###
很不幸MySQL不提供什么被存储到ibdata1共享表空间的信息但是有两个工具将会很有帮助。第一个是马克·卡拉汉制作的一个修订版本的innochecksum并且发布在[这个漏洞报告][7]。
它相当易于使用：
# ./innochecksum /var/lib/mysql/ibdata1
0 bad checksum
13 FIL_PAGE_INDEX
19272 FIL_PAGE_UNDO_LOG
230 FIL_PAGE_INODE
1 FIL_PAGE_IBUF_FREE_LIST
892 FIL_PAGE_TYPE_ALLOCATED
2 FIL_PAGE_IBUF_BITMAP
195 FIL_PAGE_TYPE_SYS
1 FIL_PAGE_TYPE_TRX_SYS
1 FIL_PAGE_TYPE_FSP_HDR
1 FIL_PAGE_TYPE_XDES
0 FIL_PAGE_TYPE_BLOB
0 FIL_PAGE_TYPE_ZBLOB
0 other
3 max index_id
全部的20608中有19272个撤销日志页。**这是表空间的93%**。
第二个检查表空间内容的方式是杰里米科尔制作的[InnoDB Ruby工具][8]。它是个更先进的工具来检查InnoDB的内部结构。例如我们可以使用space-summary参数来得到每个页面及其数据类型的列表。我们可以使用标准的Unix工具**撤销日志**页的数量：
# innodb_space -f /var/lib/mysql/ibdata1 space-summary | grep UNDO_LOG | wc -l
19272
尽管这种特殊的情况innochedcksum更快更容易使用，我推荐你使用杰里米的工具去学习更多的InnoDB内部数据分布和内部结构。
好，现在我们知道问题所在。下一个问题：
### 我能怎么解决问题？ ###
这个问题的答案很简单。如果你还能提交语句，就做吧。如果不能你必须要杀掉进程开始回滚进程。那将停止ibdata1的增长但是很清楚你的软件有一个漏洞或者出了一些错误。现在你知道如何去鉴定问题所在，你需要使用你自己的调试工具或普通语句日志找出谁或者什么引起的问题。
如果问题发生在清除线程，解决方法通常是升级到新版本，新版中使用一个独立的清除线程替代主线程。更多信息查看[文档链接][9]
### 有什么方法恢复已使用的空间么？ ###
没有，目前不可能有一个容易并且快速的方法。InnoDB表空间从不收缩...见[10年老漏洞报告][10]最新更新自詹姆斯（谢谢）：
当你删除一些行，这个页被标为已删除稍后重用，但是这个空间从不会被恢复。只有一种方式来启动数据库使用新的ibdata1。做这个你应该需要使用mysqldump做一个逻辑全备份。然后停止MySQL并删除所有数据库、ib_logfile*、ibdata1*文件。当你再启动MySQL的时候将会创建一个新的共享表空间。然后恢复逻辑仓库。
### 总结 ###
当ibdata1文件增长太快，通常是MySQL里长时间运行的被遗忘的事务引起的。尝试去解决问题越快越好（提交或者杀死事务）因为没有痛苦缓慢的mysqldump执行你不能恢复浪费的磁盘空间。
监控数据库避免这些问题也是非常推荐的。我们的[MySQL监控插件][11]包括一个Nagios脚本，如果发现了一个太老的运行事务它可以提醒你。
--------------------------------------------------------------------------------
via: https://www.percona.com/blog/2013/08/20/why-is-the-ibdata1-file-continuously-growing-in-mysql/
作者：[Miguel Angel Nieto][a]
译者：[wyangsun](https://github.com/wyangsun)
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](https://linux.cn/) 荣誉推出
[a]:https://www.percona.com/blog/author/miguelangelnieto/
[1]:https://www.percona.com/products/mysql-support
[2]:http://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html#sysvar_innodb_file_per_table
[3]:https://www.percona.com/software/percona-server
[4]:https://www.percona.com/doc/percona-server/5.5/scalability/innodb_insert_buffer.html#innodb_ibuf_max_size
[5]:https://www.percona.com/doc/percona-server/5.5/performance/innodb_doublewrite_path.html?id=percona-server:features:percona_innodb_doublewrite_path#innodb_doublewrite_file
[6]:http://dev.mysql.com/doc/refman/5.6/en/innodb-performance.html#innodb-undo-tablespace
[7]:http://bugs.mysql.com/bug.php?id=57611
[8]:https://github.com/jeremycole/innodb_ruby
[9]:http://dev.mysql.com/doc/innodb/1.1/en/innodb-improved-purge-scheduling.html
[10]:http://bugs.mysql.com/bug.php?id=1341
[11]:https://www.percona.com/software/percona-monitoring-plugins

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如何修复ubuntu 14.04中检测到系统程序错误的问题
================================================================================
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/07/system_program_Problem_detected.jpeg)
在过去的几个星期，（几乎）每次都有消息 **Ubuntu 15.04在启动时检测到系统程序错误（system program problem detected on startup in Ubuntu 15.04)** 跑出来“欢迎”我。那时我是直接忽略掉它的，但是这种情况到了某个时刻，它就让人觉得非常烦人了！
> 检测到系统程序错误(System program problem detected)
>
> 你想立即报告这个问题吗？
>
> ![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/07/System_Program_Problem_Detected.png)
我肯定地知道如果你是一个Ubuntu用户，你可能曾经也遇到过这个恼人的弹窗。在本文中，我们将探讨在Ubuntu 14.04和15.04中遇到"检测到系统程序错误(system program problem detected)"时 应该怎么办。
### 怎么解决Ubuntu中"检测到系统程序错误"的错误 ###
#### 那么这个通知到底是关于什么的？ ####
大体上讲，它是在告知你，你的系统的一部分崩溃了。可别因为“崩溃”这个词而恐慌。这不是一个严重的问题，你的系统还是完完全全可用的。只是在以前的某个时刻某个程序崩溃了，而Ubuntu想让你决定要不要把这个问题报告给开发者，这样他们就能够修复这个问题。
#### 那么，我们点了“报告错误”的按钮后，它以后就不再显示了？####
不，不是的！即使你点了“报告错误”按钮，最后你还是会被一个如下的弹窗再次“欢迎”：
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/07/Ubuntu_Internal_error.png)
[对不起，Ubuntu发生了一个内部错误(Sorry, Ubuntu has experienced an internal error)][1]是一个Apport(Apport是Ubuntu中错误信息的收集报告系统,详见Ubuntu Wiki中的Apport篇,译者注)，它将会进一步的打开网页浏览器，然后你可以通过登录或创建[Launchpad][2]帐户来填写一份漏洞（Bug)报告文件。你看,这是一个复杂的过程,它要花整整四步来完成.
#### 但是我想帮助开发者，让他们知道这个漏洞啊 !####
你这样想的确非常地周到体贴,而且这样做也是正确的。但是这样做的话，存在两个问题。第一，存在非常高的概率，这个漏洞已经被报告过了；第二，即使你报告了个这次崩溃，也无法保证你不会再看到它。
#### 那么，你的意思就是说别报告这次崩溃了？####
对，也不对。如果你想的话，在你第一次看到它的时候报告它。你可以在上面图片显示的“显示细节（Show Details)”中，查看崩溃的程序。但是如果你总是看到它，或者你不想报告漏洞（Bug)，那么我建议你还是一次性摆脱这个问题吧。
### 修复Ubuntu中“检测到系统程序错误”的错误 ###
这些错误报告被存放在Ubuntu中目录/var/crash中。如果你翻看这个目录的话，应该可以看到有一些以crash结尾的文件。
![](http://itsfoss.itsfoss.netdna-cdn.com/wp-content/uploads/2015/07/Crash_reports_Ubuntu.jpeg)
我的建议是删除这些错误报告。打开一个终端，执行下面的命令：
sudo rm /var/crash/*
这个操作会删除所有在/var/crash目录下的所有内容。这样你就不会再被这些报告以前程序错误的弹窗所扰。但是如果有一个程序又崩溃了，你就会再次看到“检测到系统程序错误”的错误。你可以再次删除这些报告文件，或者你可以禁用Apport来彻底地摆脱这个错误弹窗。
#### 彻底地摆脱Ubuntu中的系统错误弹窗 ####
如果你这样做，系统中任何程序崩溃时，系统都不会再通知你。如果你想问问我的看法的话，我会说，这不是一件坏事，除非你愿意填写错误报告。如果你不想填写错误报告，那么这些错误通知存不存在都不会有什么区别。
要禁止Apport，并且彻底地摆脱Ubuntu系统中的程序崩溃报告，打开一个终端，输入以下命令：
gksu gedit /etc/default/apport
这个文件的内容是：
# set this to 0 to disable apport, or to 1 to enable it
# 设置0表示禁用Apportw，或者1开启它。译者注，下同。
# you can temporarily override this with
# 你可以用下面的命令暂时关闭它：
# sudo service apport start force_start=1
enabled=1
把**enabled=1**改为**enabled=0**.保存并关闭文件。完成之后你就再也不会看到弹窗报告错误了。很显然，如果我们想重新开启错误报告功能，只要再打开这个文件，把enabled设置为1就可以了。
#### 你的有效吗？ ####
我希望这篇教程能够帮助你修复Ubuntu 14.04和Ubuntu 15.04中检测到系统程序错误的问题。如果这个小窍门帮你摆脱了这个烦人的问题，请让我知道。
--------------------------------------------------------------------------------
via: http://itsfoss.com/how-to-fix-system-program-problem-detected-ubuntu/
作者：[Abhishek][a]
译者：[XLCYun](https://github.com/XLCYun)
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](https://linux.cn/) 荣誉推出
[a]:http://itsfoss.com/author/abhishek/
[1]:http://itsfoss.com/how-to-solve-sorry-ubuntu-12-04-has-experienced-an-internal-error/
[2]:https://launchpad.net/

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如何管理Vim插件
================================================================================
Vim是Linux上一个轻量级的通用文本编辑器。虽然它开始时的学习曲线对于一般的Linux用户来说可能很困难，但比起它的好处，这些付出完全是值得的。随着功能的增长，在插件工具的应用下，Vim是完全可定制的。但是，由于它高级的功能配置，你需要花一些时间去了解它的插件系统，然后才能够有效地去个性化定置Vim。幸运的是，我们已经有一些工具能够使我们在使用Vim插件时更加轻松。而我日常所使用的就是Vundle.
### 什么是Vundle ###
[Vundle][1]是一个vim插件管理器，用于支持Vim包。Vundle能让你很简单地实现插件的安装，升级，搜索或者清除。它还能管理你的运行环境并且在标签方面提供帮助。
### 安装Vundle ###
首先，如果你的Linux系统上没有Git的话，先[安装Git][2].
接着，创建一个目录，Vim的插件将会被下载并且安装在这个目录上。默认情况下，这个目录为~/.vim/bundle。
$ mkdir -p ~/.vim/bundle
现在，安装Vundle如下。注意Vundle本身也是一个vim插件。因此我们同样把vundle安装到之前创建的目录~/.vim/bundle下。
$ git clone https://github.com/gmarik/Vundle.vim.git ~/.vim/bundle/Vundle.vim
### 配置Vundle　###
现在配置你的.vimrc文件如下：
set nocompatible " This is required
" 这是被要求的。（译注：中文注释为译者所加，下同。）
filetype off " This is required
" 这是被要求的。
" Here you set up the runtime path　
" 在这里设置你的运行时环境的路径。
set rtp+=~/.vim/bundle/Vundle.vim
" Initialize vundle　
" 初始化vundle
call vundle#begin()
" This should always be the first　
" 这一行应该永远放在前面。
Plugin 'gmarik/Vundle.vim'
" This examples are from https://github.com/gmarik/Vundle.vim README
" 这个示范来自https://github.com/gmarik/Vundle.vim README
Plugin 'tpope/vim-fugitive'
" Plugin from http://vim-scripts.org/vim/scripts.html
" 取自http://vim-scripts.org/vim/scripts.html的插件
Plugin 'L9'
"　Git plugin not hosted on GitHub
"　Git插件，但并不在GitHub上。
Plugin 'git://git.wincent.com/command-t.git'
"git repos on your local machine (i.e. when working on your own plugin)
"本地计算机上的Git仓库路径　（例如，当你在开发你自己的插件时）
Plugin 'file:///home/gmarik/path/to/plugin'
" The sparkup vim script is in a subdirectory of this repo called vim.
" Pass the path to set the runtimepath properly.
" vim脚本sparkup存放在这个名叫vim的仓库下的一个子目录中。
" 提交这个路径来正确地设置运行时路径
Plugin 'rstacruz/sparkup', {'rtp': 'vim/'}
" Avoid a name conflict with L9
"　避免与L9发生名字上的冲突
Plugin 'user/L9', {'name': 'newL9'}
"Every Plugin should be before this line
"所有的插件都应该在这一行之前。
call vundle#end() " required　被要求的
容我简单解释一下上面的设置：默认情况下，Vundle将从github.com或者vim-scripts.org下载和安装vim插件。你也可以改变这个默认行为。
要从github安装（安装插件，译者注，下同）:
Plugin 'user/plugin'
要从http://vim-scripts.org/vim/scripts.html处安装:
Plugin 'plugin_name'
要从另外一个git仓库中安装:
Plugin 'git://git.another_repo.com/plugin'
从本地文件中安装：
Plugin 'file:///home/user/path/to/plugin'
你同样可以定制其它东西，例如你的插件运行时路径，当你自己在编写一个插件时，或者你只是想从其它目录——而不是~/.vim——中加载插件时，这样做就非常有用。
Plugin 'rstacruz/sparkup', {'rtp': 'another_vim_path/'}
如果你有同名的插件，你可以重命名你的插件，这样它们就不会发生冲突了。
Plugin 'user/plugin', {'name': 'newPlugin'}
### 使用Vum命令 ###
一旦你用vundle设置好你的插件，你就可以通过几个vundle命令来安装，升级，搜索插件，或者清除没有用的插件。
#### 安装一个新的插件 ####
所有列在你的.vimrc文件中的插件，都会被PluginInstall命令安装。你也可以通递一个插件名给它，来安装某个的特定插件。
:PluginInstall
:PluginInstall <插件名>
![](https://farm1.staticflickr.com/559/18998707843_438cd55463_c.jpg)
#### 清除没有用的插件 ####
如果你有任何没有用到的插件,你可以通过PluginClean命令来删除它.
:PluginClean
![](https://farm4.staticflickr.com/3814/19433047689_17d9822af6_c.jpg)
#### 查找一个插件 ####
如果你想从提供的插件清单中安装一个插件,搜索功能会很有用
:PluginSearch <文本>
![](https://farm1.staticflickr.com/541/19593459846_75b003443d_c.jpg)
在搜索的时候,你可以在交互式分割窗口中安装,清除,重新搜索或者重新加载插件清单.安装后的插件不会自动加载生效,要使其加载生效,可以将它们添加进你的.vimrc文件中.
### 总结 ###
Vim是一个妙不可言的工具.它不单单是一个能够使你的工作更加顺畅高效的默认文本编辑器,同时它还能够摇身一变,成为现存的几乎任何一门编程语言的IDE.
注意,有一些网站能帮你找到适合的vim插件.猛击[http://www.vim-scripts.org][3], Github或者 [http://www.vimawesome.com][4] 获取新的脚本或插件.同时记得为你的插件使用帮助供应程序.
和你最爱的编辑器一起嗨起来吧!
--------------------------------------------------------------------------------
via: http://xmodulo.com/manage-vim-plugins.html
作者：[Christopher Valerio][a]
译者：[XLCYun(袖里藏云)](https://github.com/XLCYun)
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](https://linux.cn/) 荣誉推出
[a]:http://xmodulo.com/author/valerio
[1]:https://github.com/VundleVim/Vundle.vim
[2]:http://ask.xmodulo.com/install-git-linux.html
[3]:http://www.vim-scripts.org/
[4]:http://www.vimawesome.com/