BTRFS delete old subvolumes created by lxd

LXD
1

Hi,

I want to delete a couple of subvolumes that lxd made, unfortunately I can’t get to them.
I’ve already deleted all the containers.

e.g:

# btrfs su li -a /
ID 263 gen 78168 top level 5 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default

but:

# ls -l /var/snap/lxd/common/lxd/storage-pools/default
total 0

I think maybe the mountpoint is in an other namespace?!
How to delete them?

Thanks Frank

2

That last one is the storage pool itself, so you’d need to use lxc storage delete to delete the entire pool.

3

I deleted the storagepool.
But the subvolumes were not deleted :slight_smile:

# btrfs su li -a /
ID 263 gen 78168 top level 5 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default
...
ID 309 gen 78183 top level 263 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default/containers/samba-ad
ID 310 gen 78183 top level 263 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default/containers/samba-fs
ID 501 gen 78168 top level 263 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default/images/690801402e1d4e02c07ba2d1a29bb9a9b4825f037c12ccad8cb4d062d2450d2c
ID 502 gen 78183 top level 263 path <FS_TREE>/var/snap/lxd/common/lxd/storage-pools/default/images/feb719d316040ef23b5236fc32168a9d6d69c0baeaba30aa46916fc2069b5be6

4

nsenter --mount=/run/snapd/ns/lxd.mnt /snap/lxd/current/bin/btrfs subvol delete /var/snap/lxd/common/lxd/storage-pools/default/... should work

5

# nsenter --mount=/run/snapd/ns/lxd.mnt /snap/lxd/current/bin/btrfs subvol delete /var/snap/lxd/common/lxd/storage-pools/default/ ERROR: cannot access subvolume /var/snap/lxd/common/lxd/storage-pools/default/: No such file or directory
# nsenter --mount=/run/snapd/ns/lxd.mnt ls -l /var/snap/lxd/common/lxd/storage-pools/
total 0

Have you any idea? I think i “played” to mouch with btrfs.

6

Sounds like LXD cleaned up its stuff then, maybe try mounting the btrfs device on /mnt or something to see its content through there?

7

Yes: # mount /dev/sda4 /mnt -o subvolid=5

I was able to delete every subvolume without:
# btrfs su delete /mnt/var/snap/lxd/common/lxd/storage-pools/default
Delete subvolume (no-commit): '/mnt/var/snap/lxd/common/lxd/storage-pools/default'
ERROR: Could not destroy subvolume/snapshot: Operation not permitted

Any idea?

8

OK after reboot i was able to delete the last subvolume.

THANKS