Just deployed 9.1 in my staging cluster for testing. Running into odd backup behavior where I'm getting a ton of timeouts, the VM will hardlock and it takes a full reset of the VM to bring it back.
3x Nodes, Ceph, 20GB LAGG's between all. Zero issues on 8.X and 9.0.X.. So its new with 9.1. Running PBS 9.0.20 with SSD's for storage. Can go into more technical detail and specifics if needed.
Random VM's every time
INFO: 39% (49.6 GiB of 127.0 GiB) in 3m 25s, read: 222.0 MiB/s, write: 126.7 MiB/s
INFO: 40% (50.9 GiB of 127.0 GiB) in 3m 31s, read: 214.0 MiB/s, write: 92.7 MiB/s
INFO: 41% (52.2 GiB of 127.0 GiB) in 3m 35s, read: 353.0 MiB/s, write: 0 B/s
ERROR: VM 117 qmp command 'query-backup' failed - got timeout
INFO: aborting backup job
ERROR: VM 117 qmp command 'backup-cancel' failed - unable to connect to VM 117 qmp socket - timeout after 5979 retries
INFO: resuming VM again
ERROR: Backup of VM 117 failed - VM 117 qmp command 'cont' failed - unable to connect to VM 117 qmp socket - timeout after 450 retries
INFO: Failed at 2025-11-20 21:34:39
INFO: Starting Backup of VM 128 (qemu)
INFO: Backup started at 2025-11-20 21:34:39