安裝ubuntu后為了使下載及更新軟件包更快，需要將自帶的源更換為國內的源。以下以163為例：
1.首先備份下原始自帶源；
sudo cp sources.list /etc/apt/sources.list.backup
2.到http://mirrors.163.com的ubuntu使用幫助文檔中，下載相應版本的sources.list, 覆蓋/etc/apt/sources.list即可；
使用vim編輯器打開sources.list文件，復制粘貼替換掉剛下載好的sources.list.precise(由於本人使用的是precise-ubuntu 12.04版本的），編輯完后保存退出。
deb http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse
3.更新源
sudo apt-get update
P.S. 除了163國內還有其他源可供選擇:
★ 搜狐：http://mirrors.sohu.com/help/ubuntu.html
★ 北京理工大學
★ 中國科技大學
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