Upgrade Ubuntu Server (21.10) to the Latest Version
This guide will walk through upgrading an Ubuntu Server (21.10) to the latest version. This is very easy but there are some caveats that need addressing along the process.
Update Software
It’s important to update your software before upgrading so things go smoother and prevent failures. To update the software on the Ubuntu Server you will likely need to check and upgrade the sources list. Ubuntu has what seems like 2 repositories for their distro releases. If you look at the folders below in the release links, you will see that your distro may not be listed in the current releases repository. If this is the case, you will need to update your sources list.
Current Releases Repository
http://us.archive.ubuntu.com/ubuntu/dists/
Old Releases Repository
http://old-releases.ubuntu.com/ubuntu/dists/
Update Sources List (/etc/apt/sources.list)
Editing the sources list is rather easy. First, make a backup of your sources file by running sudo cp /etc/apt/sources.list /etc/apt/sources.list.bk . I prefer Vim but you may use Nano. Open your sources file in your editor. sudo vim /etc/apt/sources.list then run this Vim command to replace all instances of the string. :%s/us\.archive/old-releases/g This may not be the case for everyone but the general idea here is to replace whatever repository is there with the “old-releases” repository so that Ubuntu can continue to get updates.
Update Ubuntu Release
To finish the release run this command: sudo do-release-upgrade
