[SOLVED] Can't delete a subvolume

[oldgeek]

I recently had to do a rollback because the recent kernel update seemed to bork the graphics on my computer, causing frequent freezes. I changed my @ subvolume to @old and the @home subvolume to @homeold. After finishing the process, I tried to delete the 'old' subvolumes using the managing subvolume program someone on this forum wrote, and it deleted the @homeold subvolume but froze while deleting the @old subvolume. I tried the command line program, btrfs subv delete /mnt/@old, but got an error message saying that it couldn't 'destroy' the folder because it wasn't empty. Well, the @homeold subvolume wasn't empty either and it destroyed that, so I wonder why I couldn't eliminate @old. Any suggestions?

[jlittle]

This is usually caused by the existence of another subvolume located under the one you are trying to delete. I struck your problem once because there was some apt btrfs script creating before and after snapshots when doing an update, and I was unaware of their existence.

Run sudo btrfs subvolume list / and look through the results. I expect there's a subvolume /mnt/@old/something. For example, snapper puts its snapshots in .snapshots/whatever, and being "hidden" they're easily missed. It's not necessary to delete the offending nested subvolume, you can simply move it somewhere else, though I imagine you'll want to delete it.

IMO the "Directory not empty" error message is quite misleading.

[oldgeek]

Thanks, that was the problem. For some reason, there were two other subvolumes, @old/var/lib/portables and @old/var/lib/machines. I deleted the offending subvolumes, then deleted @old successfully. The question is, how did those two subvolumes get there?

[oshunluvr]

Those were left over from the upgrade installation. Sloppy. I found them here too.