為了優化ubuntu軟件安裝/更新速度，我測試了國內幾家apt源的速度，發現北京交大的apt源速度相對最快，然后可以通過以下步驟更新ubuntu源
1) 備份默認的apt源
1 $ cd /etc/apt 2 $ sudo cp sources.list sources.list.backup
2) 編輯
$ sudo gedit sources.list
復制粘貼以下列表：
1 deb http://archive.ubuntu.com/ubuntu/ raring main restricted universe multiverse 2 deb http://archive.ubuntu.com/ubuntu/ raring-security main restricted universe multiverse 3 deb http://archive.ubuntu.com/ubuntu/ raring-updates main restricted universe multiverse 4 deb http://archive.ubuntu.com/ubuntu/ raring-proposed main restricted universe multiverse 5 deb http://archive.ubuntu.com/ubuntu/ raring-backports main restricted universe multiverse 6 deb-src http://archive.ubuntu.com/ubuntu/ raring main restricted universe multiverse 7 deb-src http://archive.ubuntu.com/ubuntu/ raring-security main restricted universe multiverse 8 deb-src http://archive.ubuntu.com/ubuntu/ raring-updates main restricted universe multiverse 9 deb-src http://archive.ubuntu.com/ubuntu/ raring-proposed main restricted universe multiverse 10 deb-src http://archive.ubuntu.com/ubuntu/ raring-backports main restricted universe multiverse
3) 注意，每次修改完apt源，一定要執行一下更新
$ sudo apt-get update
大概花了幾分鍾，更新完成之后，就可以使用apt來安裝應用程序了。
備注：ubuntu apt源列表 http://wiki.ubuntu.org.cn/源列表