This issue appears in some VM configurations, such as Windows Server 2022, where the snapshot menu does not allow creating a new snapshot and prompts that the current guest configuration does not support taking snapshots.

Cause of the Problem:

The issue is due to the VM disk format, as the raw format does not support snapshots.

Windows Server 2022 is peculiar. Despite the disk format being qcow2, the presence of a TPM device, which PVE creates during Windows installation, prevents snapshots. Deleting this device allows snapshot backups.

Solution:

You need to convert the raw format image to qcow2 format to take snapshots.

Shut down the VM, log into the server, and execute the following command:

qemu-img convert -O qcow2 /var/lib/vz/images/100/vm-100-disk-0.raw /var/lib/vz/images/100/vm-100-disk-0.qcow2

Note: Replace the VMID and disk name accordingly.

After conversion, set it as a pass-through disk:

qm set 100 –scsi1 local:100/vm-100-disk-0.qcow2

Note: Replace the VMID and disk name accordingly.

After completing this, delete the previously existing scsi0 (name might differ, look for the raw format image to delete), then a new unused image will appear. Load it normally.

Finally, in the VM options interface, find the boot order, modify it to set the new disk as the boot disk, and start the VM. You should be able to add snapshots normally.