Unable to create persistent dirty-bitmap

[Prashant Patil]

Hello,
We have configured 'Directory' storage having SAN as backing storage, the SAN storage is mounted at file system path (/mnt/pve/SAN-Storage1) with type ext4. We have couple of VMs running on this storage. When we try to create a persistent bitmap on qcow2 file then that fails with below error. The disk at 'scsi0' is "scsi0: SAN-Storage1:101/vm-101-disk-1.qcow2,iothread=1,size=32G". So, the question here is, why are we getting error to create persistent bitmap for qcow2 disk?

root at be1-proxmox1:~# echo '{"execute": "qmp_capabilities"}{"execute": "block-dirty-bitmap-add", "arguments": {"node":"drive-scsi0","name":"bm_1","persistent":true}}' | socat - unix-connect:/var/run/qemu-server/101.qmp
{"QMP": {"version": {"qemu": {"micro": 2, "minor": 0, "major": 10}, "package": "pve-qemu-kvm_10.0.2-4"}, "capabilities": []}}
{"return": {}}
{"error": {"class": "GenericError", "desc": "Can't store persistent bitmaps to drive-scsi0: Operation not supported"}}
root at be1-proxmox1:~#

Thanks
Prashant