Prawdopodobnie mój obraz ucierpiał z powodu dużego obciążenia operacjami I/O mimo, iż miałem Virtio-SCSI: https://forum.proxmox.com/threads/qcow2-corruption-after-snapshot-or-heavy-disk-i-o.32865/
qemu-img check disk.qcow2
ERROR OFLAG_COPIED data cluster: l2_entry=8cfdb0000 refcount=1 43782 errors were found on the image. Data may be corrupted, or further writes to the image may corrupt it. 424996 leaked clusters were found on the image. This means waste of disk space, but no harm to data. 524288/524288 = 100.00% allocated, 10.45% fragmented, 0.00% compressed clusters Image end offset: 41744859136
If -r is specified, qemu-img tries to repair any inconsistencies found during the check. -r leaks repairs only cluster leaks, whereas -r all fixes all kinds of errors, with a higher risk of choosing the wrong fix or hiding corruption that has already occurred.
qemu-img check -r all disk.qcow2
Repairing OFLAG_COPIED data cluster: l2_entry=8000000885b30000 refcount=2
The following inconsistencies were found and repaired:
424996 leaked clusters
36838 corruptions
Double checking the fixed image now...
No errors were found on the image.
524288/524288 = 100.00% allocated, 10.45% fragmented, 0.00% compressed clusters
Image end offset: 41744859136
UWAGA! Lepiej zrobić najpierw opcję LEAKS, a potem w ostateczności ALL.
qemu-img check disk.qcow2
No errors were found on the image. 524288/524288 = 100.00% allocated, 10.45% fragmented, 0.00% compressed clusters Image end offset: 41744859136
Link do manuala: https://www.qemu.org/documentation/