ERROR: ... unable to destroy quota group: Device or resource busy

[MeisterP]

With target_qgroup_destroy yes I get errors for every subvolume on /mnt/btrfs/my-hd/:

ERROR: Failed to destroy qgroup "0/3313" for subvolume: /mnt/btrfs/my-hd/btrbk-snapshots/my-subvolume
ERROR: ... Command execution failed (exitcode=1)
ERROR: ... sh: btrfs qgroup destroy 0/3313 '/mnt/btrfs/my-hd/btrbk-snapshots/my-subvolume'
ERROR: ... unable to destroy quota group: Device or resource busy

/mnt/btrfs/my-hd/ is an internal ssd

[Vladimir-csp]

Having this too. My backup storage accumulated a lot of stale qgroups, which I'm unable to remove.

Qgroupid    Referenced    Exclusive   Path 
--------    ----------    ---------   ---- 
0/5           16.00KiB     16.00KiB   <toplevel>
0/4257        16.00EiB        0.00B   <stale>
0/4273        16.00EiB        0.00B   <stale>
0/4332        16.00EiB        0.00B   <stale>
0/4472        16.00EiB     16.00EiB   <stale>
0/4504        16.00EiB        0.00B   <stale>
0/4511       140.27MiB        0.00B   <stale>
0/4512       941.40GiB        0.00B   <stale>
0/4516        16.00EiB     16.00EiB   <stale>
0/4520        51.03GiB        0.00B   <stale>
0/4524        16.00EiB        0.00B   <stale>
0/4526        10.07GiB        0.00B   <stale>
0/4528        16.00EiB        0.00B   <stale>
0/4530         1.18TiB        0.00B   <stale>
0/4531        24.76MiB        0.00B   <stale>
0/4532        16.00EiB        0.00B   <stale>
0/4533         9.31GiB      1.29GiB   snapshots/@.20240513T0400
0/4534         3.16TiB      1.42GiB   snapshots/home.20240513T0400
0/4535         8.63GiB    511.02MiB   snapshots/@.20240629T1628
0/4536         3.18TiB    251.29MiB   snapshots/home.20240629T1628
0/4538        16.00EiB        0.00B   <stale>
0/4540        16.00EiB        0.00B   <stale>
0/4541       583.60MiB        0.00B   <stale>
0/4542       746.09GiB     16.00KiB   <stale>
0/4543         8.77GiB    503.85MiB   snapshots/@.20240708T0400
0/4544         3.15TiB    928.46MiB   snapshots/home.20240708T0400
0/4545        16.00EiB        0.00B   <stale>
0/4546        16.00EiB        0.00B   <stale>
0/4547       655.34MiB        0.00B   <stale>
0/4548        16.00EiB        0.00B   <stale>
0/4550        16.00EiB        0.00B   <stale>
0/4551        16.00EiB        0.00B   <stale>
0/4552        16.00EiB        0.00B   <stale>
0/4554       971.65GiB    464.00KiB   <stale>
0/4555       289.70MiB        0.00B   <stale>
0/4556        16.00EiB        0.00B   <stale>
0/4557       127.41MiB        0.00B   <stale>
0/4558        16.00EiB        0.00B   <stale>
0/4559         9.29GiB    481.38MiB   snapshots/@.20240805T0400
0/4560         3.20TiB    347.89MiB   snapshots/home.20240805T0400
0/4564        16.00EiB        0.00B   <stale>
0/4565        16.00EiB        0.00B   <stale>
0/4566        39.07MiB        0.00B   <stale>
0/4567        16.00EiB        0.00B   <stale>
0/4568        16.00EiB        0.00B   <stale>
0/4569        16.00EiB        0.00B   <stale>
0/4570        16.00EiB        0.00B   <stale>
0/4571         2.08TiB    150.30MiB   <stale>
0/4576        16.00EiB        0.00B   <stale>
0/4577         8.81GiB    489.26MiB   snapshots/@.20240826T0400
0/4579         3.26TiB      2.00GiB   snapshots/home.20240826T0400
0/4580        89.73MiB        0.00B   <stale>
0/4582        16.00EiB        0.00B   <stale>
0/4583         8.84GiB    488.07MiB   snapshots/@.20240902T0400
0/4584         3.26TiB    113.34MiB   snapshots/home.20240902T0400
0/4588         8.76GiB    445.28MiB   <stale>
0/4589         3.26TiB     80.16MiB   <stale>
0/4590        11.51GiB    443.86MiB   snapshots/@.20240909T0400
0/4591         3.26TiB    132.71MiB   snapshots/home.20240909T0400
0/4592        11.56GiB    450.87MiB   <stale>
0/4593         3.26TiB    132.83MiB   <stale>
0/4594        11.57GiB    450.12MiB   snapshots/@.20240916T0400
0/4595         3.26TiB    145.27MiB   snapshots/home.20240916T0400
0/4596        11.09GiB    455.03MiB   snapshots/@.20240919T0400
0/4597         3.26TiB    351.88MiB   snapshots/home.20240919T0400
0/4598        11.09GiB    447.25MiB   snapshots/@.20240923T0400
0/4599         3.26TiB    103.12MiB   snapshots/home.20240923T0400
0/4600        11.11GiB    463.07MiB   snapshots/@.20240926T0400
0/4601         3.26TiB    116.32MiB   snapshots/home.20240926T0400

[Vladimir-csp]

Source storage also has them.
Documentation suggests doing quota rescan, will try.

[Vladimir-csp]

It is quite fast and it helped.

[Vladimir-csp]

But more stale groups created on the next backup.