Windows VM Backup Failure after upgrading to PVE9

[onisokien]

Since I upgraded from PVE8 to 9 yesterday, my Windows VM has not been successfully backed up. I have two backup stores: PBS and NFS. Neither is working. Here is the error I get below:

INFO: include disk 'scsi0' 'polymath-pa2-zfs2:vm-102-disk-3' 256G
INFO: include disk 'efidisk0' 'polymath-pa2-zfs2:vm-102-disk-1' 528K
INFO: include disk 'tpmstate0' 'polymath-pa2-zfs2:vm-102-disk-2' 4M
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating Proxmox Backup Server archive 'vm/102/2025-08-07T11:46:00Z'
INFO: attaching TPM drive to QEMU for backup
INFO: skipping guest-agent 'fs-freeze', agent configured but not running?
ERROR: VM 102 qmp command 'backup' failed - Device 'drive-tpmstate0-backup' not found
INFO: aborting backup job
INFO: resuming VM again
ERROR: Backup of VM 102 failed - VM 102 qmp command 'backup' failed - Device 'drive-tpmstate0-backup' not found
INFO: Failed at 2025-08-07 05:46:03
INFO: Backup job finished with errors

VM Config

agent: 1
bios: ovmf
boot: order=scsi0
cores: 4
cpu: x86-64-v2-AES
efidisk0: polymath-pa2-zfs2:vm-102-disk-1,efitype=4m,format=raw,pre-enrolled-keys=1,size=528K
ide0: PA-VMStorage:iso/virtio-win.iso,media=cdrom,size=707456K
ide2: PA-VMStorage:iso/Win11_24H2_English_x64.iso,media=cdrom,size=5683090K
machine: pc-q35-9.0
memory: 16384
meta: creation-qemu=9.0.2,ctime=1735955486
name: pacmc-windows
net0: virtio=BC:24:11:F7:BA:6E,bridge=vmbr130,firewall=1
numa: 0
onboot: 1
ostype: win11
scsi0: polymath-pa2-zfs2:vm-102-disk-3,cache=writeback,discard=on,format=raw,iothread=1,size=256G
scsihw: virtio-scsi-single
smbios1: uuid=78db085a-2f39-4476-8fe6-0e992c211e41
sockets: 2
startup: order=2
tpmstate0: polymath-pa2-zfs2:vm-102-disk-2,size=4M,version=v2.0
vmgenid: 666ae6da-1664-4bb4-8101-c4a48b4c27af

Is anyone running into this problem?

 

[fiona]

Hi,
was the VM started fresh after the upgrade, i.e. with the new QEMU 10 binary?

Please share the output of the following commands

pveversion -v
qm status 102 --verbose
sed 's/\x0/ /g' /proc/$(cat /var/run/qemu-server/102.pid)/cmdline

 

[onisokien]

Hi @fiona, thanks for the response. I got this working after rebooting the node.

 

[fiona]

Glad to hear! Please mark the thread as SOLVED, so others can find solutions more easily. This can be done with the Edit thread button above the first post and selecting the appropriate prefix.