最近自己装了个ubuntu kylin 在使用的过程中发现，系统的apt-get 的源有毛病，总是安装不了软件。
感觉应该是传说中的墙的原因，所以准备换到阿里云的源。
下面是步骤：
1、复制原文件备份
sudo cp /etc/apt/source.list /etc/apt/source.list.bak
2、编辑源列表文件
sudo vim /etc/apt/source.list
3、将原来的列表删除，添加如下内容
deb http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse
4、运行sudo apt-get update
5、运行sudo apt-get upgrade
以上就完成了对源的更换。