I have an LXC container running on a Ceph pool. It's running just fine. It has a nightly backup set up to run. For the last week or so, the backup keeps on failing with: Code: vzdump 60180 --mailnotification always --mode snapshot --mailto email@example.com --quiet 1 --storage nas01-backup-7x --compress lzo 60180: 2018-08-29 01:00:02 INFO: Starting Backup of VM 60180 (lxc) 60180: 2018-08-29 01:00:02 INFO: status = running 60180: 2018-08-29 01:00:02 INFO: CT Name: my-lxc-container 60180: 2018-08-29 01:00:02 INFO: found old vzdump snapshot (force removal) 60180: 2018-08-29 01:00:02 INFO: backup mode: snapshot 60180: 2018-08-29 01:00:02 INFO: ionice priority: 7 60180: 2018-08-29 01:00:02 INFO: create storage snapshot 'vzdump' 60180: 2018-08-29 01:00:03 ERROR: Backup of VM 60180 failed - command 'mount -o ro,noload /dev/rbd2 /mnt/vzsnap0//' failed: exit code 32 If I list snapshots of that container, I can see a snapshot left behind. Code: # rbd --pool ceph snap ls vm-60180-disk-1 SNAPID NAME SIZE TIMESTAMP 63 vzdump 65536 MB Wed Aug 29 01:00:03 2018 Even if I clean up the snapshot with: Code: # rbd snap rm ceph/vm-60180-disk-1@vzdump ... it doesn't help. If I run a manual backup to the same storage backend, a NAS, but a different mount point, it generally works. I'm a bit baffled as to why this is failing. Anyone have any suggestions or ideas for why this is failing?