I just upgraded my omv5 machine that had a BTRFS root drive with several subvolumes (omv-upgrade) and now all my volumes are gone.
I can't take snapper snapshots anymore and the output of btrfs subvolume list / is just completely empty.
I tried creating a test-subvolume to see if the command is working properly: it does, the new subvolume is being shown, but all of my old subvolumes are gone now. Why did this happen? and how do I get them back?!