Can't Update Ubuntu 21.10 on my Linode

As of July 14, 2022, Ubuntu 21.10 codenamed Impish Indri, has reached end-of-life (EOL). There will be no more updates of any kind, including security updates, for this release of Ubuntu.

When Ubuntu passes a release to EOL, they no longer provide package updates through their mirrors. Linode sources directly from these mirrors, which is why trying to run an update through them results in an error. Older releases of Ubuntu are moved to an archive server, so you can either update your repo lists or deploy a new Linode running a newer version of Ubuntu and transfer your data over with SFTP or FileZilla. Check out the community question post below.

How do I upgrade my existing Ubuntu installation?

Updating Repo List
You can use any of the Ubuntu versions that haven't reached their EOL code name to modify your sources.list file. In the example below, I used the codename for Ubuntu 20.04 - jammy to update my Ubuntu.

sed -i -e 's/impish/jammy/g' /etc/apt/sources.list

The command above will replace every occurrence of the word impish with jammy which is the codename for the 22.04 version after which you should be able to update your Ubuntu.

I was able to run that command but then I encountered another error:

Hit:1 http://mirrors.linode.com/ubuntu jammy InRelease
Hit:2 http://mirrors.linode.com/ubuntu jammy-updates InRelease                                                                                                                                             
Hit:3 http://mirrors.linode.com/ubuntu jammy-backports InRelease                                                                                                                                           
Hit:4 http://dl.google.com/linux/chrome/deb stable InRelease                                                                                                                                               
Hit:5 http://downloads.metasploit.com/data/releases/metasploit-framework/apt lucid InRelease                                                                                                               
Hit:6 https://packages.microsoft.com/repos/azure-cli groovy InRelease                                                                                      
Get:7 https://packages.cloud.google.com/apt cloud-sdk InRelease [6,751 B]                                                            
Err:8 http://ppa.launchpad.net/phd.re/chromium-browser/ubuntu groovy InRelease                                                 
  403  Forbidden [IP: 2620:2d:4000:1::3e 80]
Hit:9 http://security.ubuntu.com/ubuntu jammy-security InRelease                             
Reading package lists... Done
E: Failed to fetch http://ppa.launchpad.net/phd.re/chromium-browser/ubuntu/dists/groovy/InRelease  403  Forbidden [IP: 2620:2d:4000:1::3e 80]
E: The repository 'http://ppa.launchpad.net/phd.re/chromium-browser/ubuntu groovy InRelease' is no longer signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Any idea how should I reaplce the source.list again to properly update my vps?

Err:8 http://ppa.launchpad.net/phd.re/chromium-browser/ubuntu groovy InRelease                                                 
  403  Forbidden [IP: 2620:2d:4000:1::3e 80]

This is an Ubuntu PPA. Just remove it from /etc/apt/source.list and run apt again. After your system updates, remove the Chromium browser with apt remove and find another source for it…or not depending on if you've ever used it (my guess is no).

Better yet, upgrade to the latest LTS release (22.04).

-- sw

it is weird because "Err:8 http://ppa.launchpad.net/phd.re/chromium-browser/ubuntu" is not in /etc/apt/source.list, nor it is "groovy" anywhere

Did you look in any of the files in /etc/apt/sources.d?

— sw