[SOLVED] Backup job error

[Zippi]

Hi everyone,
I installed PBS on a VM on unRAID, and it's always worked great.
Today I created a new VM on ProxMox and tried to backup to PBS, but it keeps giving me an error, and I don't understand why. It's always worked fine.
Both ProxMox and PBS are up to date.
This is the result ProxMox gives me when I try to backup:

INFO: starting new backup job: vzdump 503 --mode snapshot --notification-mode auto --notes-template '{{guestname}}' --node pve3 --storage PBS --remove 0
INFO: Starting Backup of VM 503 (qemu)
INFO: Backup started at 2025-07-19 19:55:52
INFO: status = stopped
INFO: backup mode: stop
INFO: ionice priority: 7
INFO: VM Name: traefik-3T
INFO: include disk 'sata0' 'local-lvm:vm-503-disk-0' 50G
INFO: creating Proxmox Backup Server archive 'vm/503/2025-07-19T17:55:52Z'
INFO: starting kvm to execute backup task
ERROR: VM 503 qmp command 'backup' failed - backup connect failed: command error: unable to read "/mnt/unraid/vm/503/owner" - No such file or directory (os error 2)
INFO: aborting backup job
INFO: stopping kvm after backup task
trying to acquire lock...
OK
ERROR: Backup of VM 503 failed - VM 503 qmp command 'backup' failed - backup connect failed: command error: unable to read "/mnt/unraid/vm/503/owner" - No such file or directory (os error 2)
INFO: Failed at 2025-07-19 19:55:54
INFO: Backup job finished with errors
INFO: notified via target `mail-to-root`
TASK ERROR: job errors

 

[Chris]

Hi,

backup connect failed: command error: unable to read "/mnt/unraid/vm/503/owner"

seems like the backup group folder /mnt/unraid/vm/503 is present in your filesystem, but the owner file in it is missing. Do you maybe recall which steps you did perform on this backup group before the backup started failing? Or did you manually interact with the datastore (e.g. rm of all the contents inside the group folder)? Also, is the folder empty or does it contain other files?

You should be able to bring your datastore back into a consistent state by removing the 503 folder if empty, so PBS recreates it and the expected owner file at the start of the next backup run. If the folder is however not empty, you will have to create the owner file and define ownership, e.g. for root@pam by writing that to the file.

 

[Zippi]

Hi,

seems like the backup group folder /mnt/unraid/vm/503 is present in your filesystem, but the owner file in it is missing. Do you maybe recall which steps you did perform on this backup group before the backup started failing? Or did you manually interact with the datastore (e.g. rm of all the contents inside the group folder)? Also, is the folder empty or does it contain other files?

You should be able to bring your datastore back into a consistent state by removing the 503 folder if empty, so PBS recreates it and the expected owner file at the start of the next backup run. If the folder is however not empty, you will have to create the owner file and define ownership, e.g. for root@pam by writing that to the file.

Hi Chris,
Thanks for the quick reply!
I simply tried to do a manual backup like I've always done with other VMs, and for some reason it doesn't work.
On PBS, if I look at my VM backups, I don't see the 503 folder.
I then tried connecting via SSH to PBS, and it had indeed created the 503 folder, but it was empty. I then tried deleting it and restarting PBS, and now everything works!
I don't know why it didn't do it the first time; I just tried to do a backup, as I've done thousands of times before without any problems.
Anyway, everything's solved now!
Thanks again for your help!!