安装完linux操作系统后，一般需要更改一下软件源，以增强软件安装的下载速度。
Ubuntu的源文件在/etc/apt/sources.list
以Wily(15.10)为例, 编辑/etc/apt/sources.list文件, 在文件最前面添加以下条目(操作前请做好相应备份)
deb http://mirrors.163.com/ubuntu/ wily main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ wily-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ wily-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ wily-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ wily-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ wily main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ wily-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ wily-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ wily-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ wily-backports main restricted universe multiverse
CentOS的源文件在/etc/yum.repos.d/CentOS-Base.repo
直接下载替换即可。
有个问题，切换软件源会导致ubuntu更新有问题，最好还是不要切换。
