安裝完linux操作系統后，一般需要更改一下軟件源，以增強軟件安裝的下載速度。
Ubuntu的源文件在/etc/apt/sources.list
以Wily(15.10)為例, 編輯/etc/apt/sources.list文件, 在文件最前面添加以下條目(操作前請做好相應備份)
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
直接下載替換即可。
有個問題，切換軟件源會導致ubuntu更新有問題，最好還是不要切換。
