1.sudo gedit /etc/apt/sources.list
编辑你的源列表，将原来的内容全部删除，添加下面列表中最适合你的源（注意不要全部添加），选择一个最合适你的即可，复制到你的列表中，然后保存列表。
2.sudo apt-get update 更新源列表信息
可以在运行“sudo apt-get update ”时查看一下错误信息，把不能连接的源删除再重新运行“sudo apt-get update ”。
3.sudo apt-get upgrade 升级
或者用ubuntu自带的更新管理器升级也可
Ubuntu 9.10源列表：
台湾
代码:
deb karmic main universe restricted multiverse
deb karmic-updates universe main multiverse restricted
deb karmic-proposed universe main multiverse restricted
deb karmic-security universe main multiverse restricted
deb karmic-backports main multiverse restricted universe
deb-src karmic main universe restricted multiverse
deb-src karmic-security universe main multiverse restricted
deb-src karmic-updates universe main multiverse restricted
deb-src karmic-proposed universe main multiverse restricted
deb-src karmic-backports universe main multiverse restricted
SRT Sources
代码:
deb karmic main restricted universe multiverse
deb karmic-security main restricted universe multiverse
deb karmic-updates main restricted universe multiverse
deb karmic-proposed main restricted universe multiverse
deb karmic-backports main restricted universe multiverse
deb-src karmic main restricted universe multiverse
deb-src karmic-security main restricted universe multiverse
deb-src karmic-updates main restricted universe multiverse
deb-src karmic-proposed main restricted universe multiverse
deb-src karmic-backports main restricted universe multiverse
搜狐（速度很快，稍微不完整）
代码:
deb karmic main restricted
deb-src karmic main restricted
deb karmic-updates main restricted
deb-src karmic-updates main restricted
deb karmic universe
deb-src karmic universe
deb karmic-updates universe
deb-src karmic-updates universe
deb karmic multiverse
deb-src karmic multiverse
deb karmic-updates multiverse
deb-src karmic-updates multiverse
北京交通大学
代码:
deb karmic main multiverse restricted universe
deb karmic-backports main multiverse restricted universe
deb karmic-proposed main multiverse restricted universe
deb karmic-security main multiverse restricted universe
deb karmic-updates main multiverse restricted universe
deb-src karmic main multiverse restricted universe
deb-src karmic-backports main multiverse restricted universe
deb-src karmic-proposed main multiverse restricted universe
deb-src karmic-security main multiverse restricted universe
deb-src karmic-updates main multiverse restricted universe
马来西亚
代码:
deb karmic main restricted universe multiverse
deb karmic-security main restricted universe multiverse
deb karmic-updates main restricted universe multiverse
deb karmic-proposed main restricted universe multiverse
deb karmic-backports main restricted universe multiverse
deb-src karmic main restricted universe multiverse
deb-src karmic-security main restricted universe multiverse
deb-src karmic-updates main restricted universe multiverse
deb-src karmic-proposed main restricted universe multiverse
deb-src karmic-backports main restricted universe multiverse
江苏双线
代码:
deb karmic main restricted universe multiverse
deb karmic-security main restricted universe multiverse
deb karmic-updates main restricted universe multiverse
deb karmic-backports main restricted universe multiverse
deb /ubuntu-cn karmic main restricted universe multiverse
deb / karmic-proposed main restricted universe multiverse
deb-src karmic main restricted universe multiverse
deb-src karmic-security main restricted universe multiverse
deb-src karmic-updates main restricted universe multiverse
deb-src karmic-backports main restricted universe multiverse
deb-src / karmic-proposed main restricted universe multiverse
日本
代码:
deb karmic main universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ karmic-security universe main multiverse restricted
deb karmic-updates universe main multiverse restricted
deb karmic-proposed universe main multiverse restricted
deb-src karmic main universe restricted multiverse
deb-src karmic-proposed universe main multiverse restricted
deb-src karmic-security universe main multiverse restricted
deb-src karmic-updates universe main multiverse restricted
