[SOLVED] ZFS data usage

[et1000]

Hello,

I'm new to ZFS and PVE. I have a VM with a 715GB disk, mapped on a ZFS pool. The disk was near full, and the ZFS pool too.
I deleted around 500G of data on that disk. On the VM CLI, df -h shows me +500GB available.
But on PVE, nothing changed. My ZFS pool is still near full, and when I backup the VM, it still backups the 715GB.

zfs list -t snapshot show me no snapshot for this VM.

Is this because ZFS is thick provisionned? Or thin when we add data, but it can only grows?

Thanks for your help
Emile

 

[leesteken]

You ZFS storage is thin otherwise its usage would not have grown. Did you trim the filesystem inside the VM? Did you enable Discard on the virtual disks and use VirtIO SCSI? More information in the manual: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#qm_hard_disk_discard
EDIT: Also, more information on this forum where this is not an uncommon question and often easily solved by enabling discard/trim on the entire IO chain.

 

[et1000]

Ah yes, you got it. I activated discard and then trimmed my disk.
Thank you!