ubuntu server 更换阿里云源（用户更新源）

Ubuntu安装完毕后，默认使用的是官方的源，在国内访问速度很慢，这里介绍更换为阿里云的源方法。

步骤如下：

1.备份源配置文件

sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup

2.用编辑器打开源配置文件

sudo vim /etc/apt/sources.list

3.删除文件内容，更换为以下内容（也可使用其他源）

deb http://mirrors.aliyun.com/ubuntu trusty main restricteddeb-src http://mirrors.aliyun.com/ubuntu trusty main restricted## Major bug fix updates produced after the final release of the## distribution.deb http://mirrors.aliyun.com/ubuntu trusty-updates main restricteddeb-src http://mirrors.aliyun.com/ubuntu trusty-updates main restricted## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu## team. Also, please note that software in universe WILL NOT receive any## review or updates from the Ubuntu security team.deb http://mirrors.aliyun.com/ubuntu trusty universedeb-src http://mirrors.aliyun.com/ubuntu trusty universedeb http://mirrors.aliyun.com/ubuntu trusty-updates universedeb-src http://mirrors.aliyun.com/ubuntu trusty-updates universe## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu## team, and may not be under a free licence. Please satisfy yourself as to## your rights to use the software. Also, please note that software in## multiverse WILL NOT receive any review or updates from the Ubuntu## security team.deb http://mirrors.aliyun.com/ubuntu trusty multiversedeb-src http://mirrors.aliyun.com/ubuntu trusty multiversedeb http://mirrors.aliyun.com/ubuntu trusty-updates multiversedeb-src http://mirrors.aliyun.com/ubuntu trusty-updates multiverse## N.B. software from this repository may not have been tested as## extensively as that contained in the main release, although it includes## newer versions of some applications which may provide useful features.## Also, please note that software in backports WILL NOT receive any review## or updates from the Ubuntu security team.deb http://mirrors.aliyun.com/ubuntu trusty-backports main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu trusty-backports main restricted universe multiversedeb http://security.ubuntu.com/ubuntu trusty-security main restricteddeb-src http://security.ubuntu.com/ubuntu trusty-security main restricteddeb http://security.ubuntu.com/ubuntu trusty-security universedeb-src http://security.ubuntu.com/ubuntu trusty-security universedeb http://security.ubuntu.com/ubuntu trusty-security multiversedeb-src http://security.ubuntu.com/ubuntu trusty-security multiverse ```4.执行以下命令，刷新 ```sudo apt-get cleansudo apt-get update 

zhuan zi : http://www.2cto.com/os/201512/452041.html