The normal version of Ubuntu supports limited time, and after the support time, the update source will be deactivated, such as ubuntu9.10 original source is invalid (including official source, similar to USTC third-party source, because these third-party sources are also synchronized with the official source). Therefore, it is not possible to install the update software directly with the original source list. To solve this problem, Ubuntu officially has a old-release image (http://old-releases.ubuntu.com/) that can be updated with this source. For example, the source list for 9.10 is as follows:
deb http://old-releases.ubuntu.com/ubuntu/ karmic main restricted universe multiversedeb http://old-releases.ubuntu.com/ubuntu/ karmic-security main restricted universe multiversedeb http://old-releases.ubuntu.com/ubuntu/ karmic-updates main Restricted universe multiversedeb http://old-releases.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiversedeb http://old-releases.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiversedeb-src http:// Old-releases.ubuntu.com/ubuntu/ karmic main restricted universe multiversedeb-src http://old-releases.ubuntu.com/ubuntu/ karmic-security main restricted universe multiversedeb-src http://old-releases.ubuntu.com/ubuntu/ karmic-updates main Restricted universe multiversedeb-src http://old-releases.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiversedeb-src http://old-releases.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse
Other versions of the only need to speak karmic changed to its version code. This expires version can also continue to use.
Stop supporting the old version of Ubuntu source list-old-releases