Upgrade from Debian/KDE to Kubuntu

So I have upgraded one of my systems from Debian bookworm to Kubuntu 20.04, this system was freezing a lot on bookworm so it is better to have something more stable/reliable. The other bookworm system has also been migrated to Kubuntu. Current plans are to use the built-in upgrader to take it up to 22.04 (next LTS) at the time that Kubuntu reaches its first point release which is when the upgrade installer will appear by default i.e. at 22.04.1. This will certainly be a progression from reinstalling as has been the past norm.

There are naturally going to be a few glitches or hiccups going from Debian/KDE. It is notable that in Kubuntu 20.04, x11 is still the default windowing environment; I would be surprised if Wayland didn’t become default in 22.04 but KDE is different because it has taken longer for them to get it working than on GNOME, where it has been the default windowing environment for longer (even in Debian).

Anyway here is a list of some migration issues found so far:

  • RAID-1 support needs to be manually installed as per instructions on previous post from RAID-1 series (mdadm) as the installer does not provide this during installation (as debian does).
  • Before setting up mdadm the device mapper settings need to be removed by running the command dmsetup remove_all otherwise this causes issues setting up the RAID array causing it to be mounted read-only as the drives end up being mapped by device mapper.
  • KDE-specific profile settings from debian may need to be removed if there are issues like, for example, panels not working correctly or hibernation buttons missing. Profile config settings are generally stored in . directories although it isn’t entirely clear which paths are relevant to KDE itself and you’ll want to ensure non-KDE paths things like .mozilla and .thunderbird are kept, as well as local flatpak app repos and settings (.local/share/flatpak and .var/app, respectively). To remove settings from the main user profile you need to restart the system in recovery mode and login as root to ensure files are not in use by the system.

Other unrelated issues:

  • If you use Krfb to share your desktop, untick the setting to store the password in your wallet, this is not very secure but at least the password will not change every time you reboot.

So now having completed reinstallation basics it is just a case of having to reinstall various applications which is straightforward enough. Since first drafting this the blogging computer in the front room has also been running Kubuntu, and has been reinstalled with a SSD for better performance.