我使用 Ubuntu 9.04 作为多用途服务器，所以这里没有 GUI。我有一段时间没有使用它了，现在当尝试使用 apt-get 安装或更新软件包时，它会引发错误。
错误消息的摘录：
root@vps609:/home# sudo apt-get update
Err http://security.canonical.com jaunty-security Release.gpg
Could not resolve 'security.canonical.com'
Err http://security.canonical.com jaunty-security/universe Translation-en_US
Could not resolve 'security.canonical.com'
Get:3 http://archive.canonical.com jaunty Release [10.5kB]
Get:4 http://archive.canonical.com jaunty-updates Release [10.5kB]
Fetched 21.4kB in 0s (56.3kB/s)
Reading package lists... Done
W: Failed to fetch http://security.canonical.com/ubuntu/dists/jaunty-security/Release.gpg n_US.bz2 Could not resolve 'security.canonical.com'
W: Failed to fetch http://archive.canonical.com/ubuntu/dists/jaunty-updates/Release Unable to find expected entry universe/binary-amd64/Packages in Meta-index file (malformed Release file?)
W: Some index files failed to …