我在虚拟主机上运行 Ubuntu 11.10。我尝试通过运行升级到较新的版本do-release-upgrade，但升级过程失败并出现以下错误。
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Sources
Err http://ppa.launchpad.net precise/main amd64 Packages
Err http://ppa.launchpad.net precise/main i386 Packages
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Sources
404 Not Found
Err http://ppa.launchpad.net precise/main amd64 Packages
404 Not Found
Err http://ppa.launchpad.net precise/main i386 Packages
404 Not Found
Err http://ppa.launchpad.net precise/main Translation-en
Err http://ppa.launchpad.net precise/main Translation-en
Ign http://ppa.launchpad.net precise/main Translation-en
Ign http://ppa.launchpad.net precise/main Translation-en
Ign http://ppa.launchpad.net precise/main Translation-en
Fetched 0 B in 0s (0 B/s)
Error during update
A problem occurred during the update. This is usually some sort of
network problem, please check your network connection and retry.
W:Failed to fetch
http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/precise/main/source/Sources
404 Not Found
, W:Failed to fetch
http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/precise/main/binary-amd64/Packages
404 Not Found
, W:Failed to fetch
http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/precise/main/binary-i386/Packages
404 Not Found
, E:Some index files failed to download. They have been ignored, or
old ones used instead.
Restoring original system state
答案1
删除 ppa 并更新：
sudo sudo add-apt-repository --remove ferramroberto/java
sudo apt-get update