@girish I followed the notes exactly (on this day I updated from Ubuntu 18 to 20 to 22) and I'm impressed how well and smooth everything worked out in general (thanks for the documentation work).
It's just the collectd thing that should be updated at the moment up until there is some feedback from the maintainers.
I just found this forum post after happily following the documentation: https://docs.cloudron.io/guides/upgrade-ubuntu-22/ and ran into the problems afterwards.
There is no hint in the documentation about the collectd-missing problem or any suggestion to wait with upgrades to 22.04.
For the moment being I installed collectd and collectd-core manually as was suggested in the referenced launchpad forum. Fingers crossed that this is a stable solution, because
a) after rebooting the machine collectd initially failed collectd.service: Failed with result 'start-limit-hit'., manually restarting it with systemctl worked
b) installing the collectd packages with apt said N: Download is performed unsandboxed as root as file '/root/collectd-core_5.12.0-9_amd64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied).
We'll see.
