Unable to delete a btrfs snapshot

[iosonopiero (Piero)]

Hello people,
A few days ago, I had issues because I could not delete a snapshot taken with Timeshift.
I tried to Google possible solutions. Then I made a huge mistake.
I used “rm” as sudo.
And this is how I reinstalled Fedora from scratch!

I’ve been using Timeshift, and it is handy.
But now I can’t delete a snapshot.

It’s the first one on the list.
If I try to delete it, I get a message about snapshots deleted with errors (sorry, I have a message in Italian, so I don’t know how the message is precisely in English).

Now,

sudo btrfs scrub start /

gave no errors, so I’m looking for help removing that snapshot.

Then, is there another GUI for managing Btrfs snapshots?

Thanks,
Piero

[emanuc (Emanuele)]

Can you show the list of subvolumes with this command?
sudo btrfs subvolume list -t /

Yes, Btrfs Assistant

[iosonopiero (Piero)]

Yes, I see this

ID	gen	top level	path
–	—	---------	----
256	5862	5		timeshift-btrfs/snapshots/2023-08-13_09-24-31/@
257	5996	5		@home
258	1954	256		timeshift-btrfs/snapshots/2023-08-13_09-24-31/@/var/lib/machines
277	5996	5		@
301	5817	277		var/lib/machines

[iosonopiero (Piero)]

@emanuc

Yes, Btrfs Assistant

I’m trying it!
Thanks!

[emanuc (Emanuele)]

You have a nested subvolume “var/lib/machines”, you need to delete it before you can delete the snapshot:
sudo btrfs subvolume delete /patch/timeshift-btrfs/snapshots/2023-08-13_09-24-31/@/var/lib/machines

“patch” is the Timeshift mount path, it should be: /run/timeshift/backup
you have to check.
Or use Btrfs Assistant to easily remove it from GUI:
sudo dnf install btrfs-assistant

I recommend that you remove that nested subvolume to not have the same problem again:
sudo btrfs subvolume delete /var/lib/machines

[iosonopiero (Piero)]

var/lib/machines ???
Is this something related to QEMU?

[emanuc (Emanuele)]

Btrfs Subvolumes

The installer will add subvolumes to fstab for any subvolumes used in the installation; either created by the installer or by the user or subvolumes reused by the user (e.g. reusing the home subvolume for an otherwise clean installation with a new root subvolume). var/lib/machines was created by systemd, not the installer, and it is a so-called “nested” subvolume as are all the other subvolumes you created. Nesting happens anytime the subvolume is not located in top level ID 5. https://btrfs.…

[iosonopiero (Piero)]

Grazie mille!!!

[iosonopiero (Piero)]

It’s strange, I think.
I installed Btrfs-Assistant hours ago, and now I’ve seen no snapshots have been done.
I set the options in this way:

then

and

When I installed the program and removed TimeShift,
I created a couple of snapshots to test it, then I removed them.
But now, this is weird.

[iosonopiero (Piero)]

It’s working correctly. I didn’t do anything.

[dalto]

Did you reboot? It is possible the timeline timer was enabled but not started yet.

[iosonopiero (Piero)]

I don’t know.
Compared to my Windows experience, with Linux, I forgot to reboot, to be honest.
Maybe it was that.

[dalto]

You can start a timer without rebooting, I was just thinking that perhaps it hadn’t been started and if you rebooted that would have started it.

The timeline timer should always take snapshots every hour.

[iosonopiero (Piero)]

It’s doing this right now.
I posted at 15:53,
and at 16:00, it did the first snapshot.