第一种方法:

cd /etc/apt/

cat sources.list |sed s/us.archive/cn.archive/g > a.txt

mv sources.list  sources.list.bak  && touch sources.list && cat a.txt > sources.list  &&  rm a.txt -rf  ##更改源为CN速度更快

 

第二种方法:

 

# deb cdrom:[Ubuntu-Server 11.04 _Natty Narwhal_ - Release amd64 (20110426)]/ natty main restricted

 

#deb cdrom:[Ubuntu-Server 11.04 _Natty Narwhal_ - Release amd64 (20110426)]/ natty main restricted

 

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

# newer versions of the distribution.

deb http://ubuntu.cn99.com/ubuntu/ natty main restricted

deb-src http://ubuntu.cn99.com/ubuntu/ natty main restricted

 

## Major bug fix updates produced after the final release of the

## distribution.

deb http://ubuntu.cn99.com/ubuntu/ natty-updates main restricted

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates main restricted

 

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team.

deb http://ubuntu.cn99.com/ubuntu/ natty universe

deb-src http://ubuntu.cn99.com/ubuntu/ natty universe

deb http://ubuntu.cn99.com/ubuntu/ natty-updates universe

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates universe

 

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 

## team, and may not be under a free licence. Please satisfy yourself as to 

## your rights to use the software. Also, please note that software in 

## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team.

deb http://ubuntu.cn99.com/ubuntu/ natty multiverse

deb-src http://ubuntu.cn99.com/ubuntu/ natty multiverse

deb http://ubuntu.cn99.com/ubuntu/ natty-updates multiverse

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates multiverse

 

## Uncomment the following two lines to add software from the 'backports'

## repository.

## N.B. software from this repository may not have been tested as

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.

# deb http://ubuntu.cn99.com/ubuntu/ natty-backports main restricted universe multiverse

# deb-src http://ubuntu.cn99.com/ubuntu/ natty-backports main restricted universe multiverse

 

deb http://security.ubuntu.com/ubuntu natty-security main restricted

deb-src http://security.ubuntu.com/ubuntu natty-security main restricted

deb http://security.ubuntu.com/ubuntu natty-security universe

deb-src http://security.ubuntu.com/ubuntu natty-security universe

deb http://security.ubuntu.com/ubuntu natty-security multiverse

deb-src http://security.ubuntu.com/ubuntu natty-security multiverse

 

## Uncomment the following two lines to add software from Canonical's

## 'partner' repository.

## This software is not part of Ubuntu, but is offered by Canonical and the

## respective vendors as a service to Ubuntu users.

# deb http://archive.canonical.com/ubuntu natty partner

# deb-src http://archive.canonical.com/ubuntu natty partner

 

## Uncomment the following two lines to add software from Ubuntu's

## 'extras' repository.

## This software is not part of Ubuntu, but is offered by third-party

## developers who want to ship their latest software.

# deb http://extras.ubuntu.com/ubuntu natty main

# deb-src http://extras.ubuntu.com/ubuntu natty main

root@class001:~# cat /etc/apt/sources.list |grep deb*

# deb cdrom:[Ubuntu-Server 11.04 _Natty Narwhal_ - Release amd64 (20110426)]/ natty main restricted

#deb cdrom:[Ubuntu-Server 11.04 _Natty Narwhal_ - Release amd64 (20110426)]/ natty main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

deb http://ubuntu.cn99.com/ubuntu/ natty main restricted

deb-src http://ubuntu.cn99.com/ubuntu/ natty main restricted

deb http://ubuntu.cn99.com/ubuntu/ natty-updates main restricted

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates main restricted

deb http://ubuntu.cn99.com/ubuntu/ natty universe

deb-src http://ubuntu.cn99.com/ubuntu/ natty universe

deb http://ubuntu.cn99.com/ubuntu/ natty-updates universe

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates universe

## team, and may not be under a free licence. Please satisfy yourself as to 

deb http://ubuntu.cn99.com/ubuntu/ natty multiverse

deb-src http://ubuntu.cn99.com/ubuntu/ natty multiverse

deb http://ubuntu.cn99.com/ubuntu/ natty-updates multiverse

deb-src http://ubuntu.cn99.com/ubuntu/ natty-updates multiverse

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

# deb http://ubuntu.cn99.com/ubuntu/ natty-backports main restricted universe multiverse

# deb-src http://ubuntu.cn99.com/ubuntu/ natty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu natty-security main restricted

deb-src http://security.ubuntu.com/ubuntu natty-security main restricted

deb http://security.ubuntu.com/ubuntu natty-security universe

deb-src http://security.ubuntu.com/ubuntu natty-security universe

deb http://security.ubuntu.com/ubuntu natty-security multiverse

deb-src http://security.ubuntu.com/ubuntu natty-security multiverse

# deb http://archive.canonical.com/ubuntu natty partner

# deb-src http://archive.canonical.com/ubuntu natty partner

## developers who want to ship their latest software.

# deb http://extras.ubuntu.com/ubuntu natty main

# deb-src http://extras.ubuntu.com/ubuntu natty main