Migrate from mythbuntu 18.04 to xubuntu 20.04

I've been running a mythbuntu machine for the best part of 10 years now. I don't use the MythTV stuff any more but it runs as bit of a quasi home server. Over the years I've set up and configured a LOT of stuff, a lot of it I probably don't even remember. I'd like to keep this machine reasonably up to date but really don't want to do a fresh install and reconfigure everything. Is there a way to migrate the system to something light like say xubuntu and upgrade it to 20.04 without a new install?

At the moment I can't update to 20.04:

phil@htpcserver:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
There is no development version of an LTS available.
To upgrade to the latest non-LTS develoment release
set Prompt=normal in /etc/update-manager/release-upgrades.

Thanks for any help

3 Answers

Mythbuntu is discontinued since 4 years. You can't upgrade to any flavor of 20.04. You have to do a fresh install.

Upgrading to Ubuntu 20 is possible. I went from mythbuntu on Ubuntu 16 -> Ubuntu 18 LTS with no problems. I then upgraded to Ubuntu 20 LTS, and again it went mostly OK.

The one gotcha is that mythfilldatabase takes a very long time (~45 minutes) since moving to 20 and mysql 8.x. Not sure why.

The mythtv project had a page on MySQL tuning, but it's really about MySQL 5.x and several lines of the suggested config file need to be commented out for MySQL 8 to start. And...even with that config, mythfilldatabase still runs slowly.

Thanks All, I did manage to get this done some time ago. From memory I ran the command recommended by NicholasSmith above to update to 20.04. I then installed Xubuntu desktop and uninstalled all the mythbuntu stuff. Went surprisingly smoothly as I recall. Still running well.