backup failed because of missing disk, but missing disk is excluded from backup

[RolandK]

hello,

is this failure to be expected ?

the disks which are excluded from backup are temporary being pulled from the server, but i don't want to disable backup from this machine, as it would perhaps be forgotten to re-add it later on...

INFO: starting new backup job: vzdump 101 102 103 104 136 100 --quiet 1 --mailnotification always --compress zstd --notes-template '{{guestname}}' --storage pve-knac-backup_auf_ds1 --mailto <hidden> --mode snapshot
INFO: Starting Backup of VM 103 (qemu)
INFO: Backup started at 2023-12-02 14:13:50
INFO: status = stopped
INFO: backup mode: stop
INFO: ionice priority: 7
INFO: VM Name: tmbackup02.disabled
INFO: include disk 'scsi0' 'vms-files:103/vm-103-disk-0.qcow2' 15G
INFO: include disk 'scsi1' 'vms-files:103/vm-103-disk-1.qcow2' 50G
INFO: exclude disk 'scsi5' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVE62H' (backup=no)
INFO: exclude disk 'scsi6' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVWM7H' (backup=no)
INFO: exclude disk 'scsi7' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVWSKH' (backup=no)
INFO: exclude disk 'scsi8' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVE7VH' (backup=no)
INFO: exclude disk 'scsi9' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVBWYH' (backup=no)
INFO: exclude disk 'scsi10' '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVWPPH' (backup=no)
INFO: creating vzdump archive '/mnt/pve/pve-knac-backup_auf_ds1/dump/vzdump-qemu-103-2023_12_02-14_13_50.vma.zst'
INFO: starting kvm to execute backup task
kvm: -drive file=/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVE62H,if=none,id=drive-scsi5,format=raw,cache=none,aio=io_uring,detect-zeroes=off: Could not open '/dev/disk/by-id/ata-HGST_HUH721212ALE600_AAGVE62H': No such file or directory
ERROR: Backup of VM 103 failed - start failed: QEMU exited with code 1
INFO: Failed at 2023-12-02 14:13:50

happens both for vzdump full backup and pbs backup

 

[Dunuin]

You can't start a VM that got defined devices that are missing. And a backup job needs to start (but not to boot) that VM in order to be able to access the virtual disks. So no, if you want to backup that VM you would need to plug in those disks again or remove scsi5 to scsi10 from the VM.

 

[sb-jw]

But he has set the flag for "no backup" and therefore the behavior here is wrong. He obviously wants to save these disks, but according to the settings he's not supposed to.

 

[Dunuin]

But he has set the flag for "no backup" and therefore the behavior here is wrong. He obviously wants to save these disks, but according to the settings he's not supposed to.

It doesn't matter. A VM without the defined disks present will simply fail to start. It's a non-functioning VM without those disks present. And you can't backup a non-functioning VM, as you need to start it, for that, as the disks are accessed on the QEMU level so the KVM process virtualizing that VM has to be running. No matter if the disks are excluded or not. Would be the same with defined PCI passthrough of a GPU and the GPU is missing or already in use by another VM. The backup would fail too.

With the scsi5 to scsi10 present in the VMs config file you tell the VM to use those 6 disks. It tries to use them when the backup job tries to start the VM which obviously won't work with the disks not present so starting the VM will fail and then the backup task will fail too. So simply don't tell the VM to do something that isn't possible. Remove scsi5 to scsi10 from the VM and add "disk passthrough via qm set" later once the disks are plugged in again.

 

[RolandK]

ok, i understand. thanks for explaining.