I have many Ubuntu server instances, it for the 20.04 version. To keep all updated I always use
sudo apt update
sudo apt upgrade
Suddenly just for one instance it did do an upgrade from 20.04 to 20.10. I don’t have idea why. Therefore I have now problems with the repositories as mentioned here:
In the comments of the previous post. Exists the following:
some desktop on your server?
grep Prompt /etc/update-manager/release-upgrades
About the question, I had this experience:
That happened for all the instances and was fixed. But again this undesired upgrade just happened just one instance.
And about the grep Prompt /etc/update-manager/release-upgrades command it returns Prompt=normal
- Why did this undesired upgrade from 20.04 to 20.10 happened?
- How configure Ubuntu to avoid repeat that scenario?.
I had many Ubuntu servers based with the 18.04 version and I never had this experience about an undesired upgrade to 20.04. Well, in that case the VirtualBox: Ubuntu Server loads GUI for Login never happened because neither Erlang nor RabbitMQ were installed.
>Solution :
Ubuntu 20.04 LTS is supported until 2025 for free, then for 2030 with paid ESM.
Having Prompt=normal on LTS is bad idea. Currently 20.10 is EOL.
To prevent upgrades from LTS to non-LTS versions you have to edit /etc/update-manager/release-upgrades and set Prompt=lts here by using any text-editor like nano.
For release list see https://wiki.ubuntu.com/Releases and https://ubuntu.com/about/release-cycle .