Ubuntu Update 404 Not Found

提示
W: 无法下载 http://mirrors.aliyun.com/ubuntu/dists/raring-backports/restricted/b inary-i386/Packages 404 Not Found [IP: 112.124.140.210 80]

Ubuntu 11.04 (Natty) 已经停止支持,但可以使用old-releases源了,先备份源列表文件:
sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup

sudo gedit /etc/apt/sources.list
把里面的内容替换为以下内容:
deb http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse

重载源列表,使配置生效:
sudo apt-get update