ubutnu12.10自带的更新源已经失效，国内各大服务器的更新源，无论是网易、搜狐还是教育网的因此也失效了。附件是ubuntu12.10目前的可用更新源。

将地址中的“us.archive”换成“old-releases”，其它版本的ubuntu类似操作。

#deb cdrom:[Ubuntu 12.10 _Quantal Quetzal_ - Release amd64 (20121017.5)]/ quantal main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://old-releases.ubuntu.com/ubuntu/ quantal main restricted
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://old-releases.ubuntu.com/ubuntu/ quantal-updates main restricted
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal-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://old-releases.ubuntu.com/ubuntu/ quantal universe
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal universe
deb http://old-releases.ubuntu.com/ubuntu/ quantal-updates universe
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal-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://old-releases.ubuntu.com/ubuntu/ quantal multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal multiverse
deb http://old-releases.ubuntu.com/ubuntu/ quantal-updates multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal-updates multiverse

## 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://old-releases.ubuntu.com/ubuntu/ quantal-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ quantal-backports main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu quantal-security main restricted
deb-src http://old-releases.ubuntu.com/ubuntu quantal-security main restricted
deb http://old-releases.ubuntu.com/ubuntu quantal-security universe
deb-src http://old-releases.ubuntu.com/ubuntu quantal-security universe
deb http://old-releases.ubuntu.com/ubuntu quantal-security multiverse
deb-src http://old-releases.ubuntu.com/ubuntu quantal-security multiverse

原更新源网址：http://us.archive.ubuntu.com/ubuntu/
所有ubuntu旧版更新源网址：http://old-releases.ubuntu.com/ubuntu/