No using ZFS , just lvm with Intel P3605 nvme , target nfs server
root@pve1:~# pveversion
pve-manager/7.3-6/723bb6ec (running kernel: 5.15.85-1-pve)
Restore Ubuntu 20 VM , VM started ok
then perform backup
INFO: starting new backup job: vzdump 1004 --notes-template '{{guestname}}' --compress zstd --storage XPEN6 --remove 0 --node pve1 --mode stop
INFO: Starting Backup of VM 1004 (qemu)
INFO: Backup started at 2023-02-28 10:26:42
INFO: status = stopped
INFO: backup mode: stop
INFO: ionice priority: 7
INFO: VM Name: ansible1
INFO: include disk 'scsi0' 'local-lvm:vm-1004-disk-0' 32G
INFO: creating vzdump archive '/mnt/pve/XPEN6/dump/vzdump-qemu-1004-2023_02_28-10_26_42.vma.zst'
INFO: starting kvm to execute backup task
INFO: started backup task '1036cb35-745d-483f-be95-2bb9384c3d3b'
INFO: 2% (783.0 MiB of 32.0 GiB) in 3s, read: 261.0 MiB/s, write: 225.7 MiB/s
INFO: 4% (1.4 GiB of 32.0 GiB) in 6s, read: 232.0 MiB/s, write: 223.0 MiB/s
INFO: 6% (2.1 GiB of 32.0 GiB) in 9s, read: 238.0 MiB/s, write: 200.6 MiB/s
INFO: 20% (6.7 GiB of 32.0 GiB) in 12s, read: 1.5 GiB/s, write: 151.8 MiB/s
INFO: 22% (7.3 GiB of 32.0 GiB) in 15s, read: 217.5 MiB/s, write: 212.0 MiB/s
INFO: 25% (8.2 GiB of 32.0 GiB) in 18s, read: 315.4 MiB/s, write: 209.2 MiB/s
INFO: 28% (9.0 GiB of 32.0 GiB) in 21s, read: 275.5 MiB/s, write: 218.5 MiB/s
INFO: 44% (14.2 GiB of 32.0 GiB) in 24s, read: 1.7 GiB/s, write: 153.9 MiB/s
INFO: 62% (20.1 GiB of 32.0 GiB) in 27s, read: 2.0 GiB/s, write: 164.2 MiB/s
INFO: 76% (24.5 GiB of 32.0 GiB) in 30s, read: 1.5 GiB/s, write: 183.2 MiB/s
INFO: 88% (28.2 GiB of 32.0 GiB) in 33s, read: 1.2 GiB/s, write: 156.4 MiB/s
INFO: 95% (30.6 GiB of 32.0 GiB) in 36s, read: 806.0 MiB/s, write: 163.8 MiB/s
INFO: 100% (32.0 GiB of 32.0 GiB) in 38s, read: 734.9 MiB/s, write: 79.3 MiB/s
INFO: backup is sparse: 25.22 GiB (78%) total zero data
INFO: transferred 32.00 GiB in 38 seconds (862.3 MiB/s)
INFO: stopping kvm after backup task
INFO: archive file size: 2.45GB
INFO: adding notes to backup
INFO: Finished Backup of VM 1004 (00:01:00)
INFO: Backup finished at 2023-02-28 10:27:42
INFO: Backup job finished successfully
TASK OK