Hi,
I have a three nodes Proxmox cluster with Ceph storage using NVMe disks.
I have observed that when I restore a virtual machine from a previos backup, its virtual disk used space is different from the provisioned one:
# rbd du -p cephVM vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 14 GiB
But if I move this VM from its current Ceph pool (with the virtual machine on) to other Ceph pool, the used space equals the provisioned one:
# rbd du -p test vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 32 GiB
If repeat the procedure but now with the virtual machine stopped, its used space is nearly the provisioned one, but is not the same that was before the pool migration:
# rbd du -p test vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 30 GiB
If I make a backup of the virtual machine and restore it over any Ceph pool, the used space is the same that I had before the Ceph pool migration:
# rbd du -p cephVM vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 14 GiB
Why is happening this?
Why when I move a virtual disk from an alive virtual machine between Ceph pools the used space equals the provisioned one?
Is it possible avoid it?
I think that is better that the used space remains the same when I move disk between Ceph pools for avoid unexpected surprises like that the Ceph storage gets full after a pool migration.
Best regards.
========================================
SOLTECSIS SOLUCIONES TECNOLOGICAS, S.L.
Carles Xavier Munyoz Baldó
Departamento de I+D+I
Tel./Fax: 966 446 046
cmunyoz@soltecsis.com
www.soltecsis.com
========================================
I have a three nodes Proxmox cluster with Ceph storage using NVMe disks.
I have observed that when I restore a virtual machine from a previos backup, its virtual disk used space is different from the provisioned one:
# rbd du -p cephVM vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 14 GiB
But if I move this VM from its current Ceph pool (with the virtual machine on) to other Ceph pool, the used space equals the provisioned one:
# rbd du -p test vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 32 GiB
If repeat the procedure but now with the virtual machine stopped, its used space is nearly the provisioned one, but is not the same that was before the pool migration:
# rbd du -p test vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 30 GiB
If I make a backup of the virtual machine and restore it over any Ceph pool, the used space is the same that I had before the Ceph pool migration:
# rbd du -p cephVM vm-105-disk-0
NAME PROVISIONED USED
vm-105-disk-0 32 GiB 14 GiB
Why is happening this?
Why when I move a virtual disk from an alive virtual machine between Ceph pools the used space equals the provisioned one?
Is it possible avoid it?
I think that is better that the used space remains the same when I move disk between Ceph pools for avoid unexpected surprises like that the Ceph storage gets full after a pool migration.
Best regards.
========================================
SOLTECSIS SOLUCIONES TECNOLOGICAS, S.L.
Carles Xavier Munyoz Baldó
Departamento de I+D+I
Tel./Fax: 966 446 046
cmunyoz@soltecsis.com
www.soltecsis.com
========================================