Hard Disk Size VM < ZFS USED

[moxiprox]

Hello,

I'm currently trying to find the reason for a size discrepancy between the Hard Disk of a VM and the ZFS used size on storage.

A Windows VM was created with a 500 GB Hard Disk on a ZFS Storage. Then this disk was expanded within Windows Disk Management to 1500 GB.

"zfs list" shows:

USED: 3.72 T
AVAIL: 1.98 T
REFER: 1.04 T

I can't explain to myself this output.

The Usage summary in Proxmox menu of that ZFS Storage seems to calculate with 3.72 T.
The menu ZFS Storage / VM Disks shows this Disk with 1.65 T.

Can someone please help me with this problem? What's the reason for this?

Thanks a lot!

 

[Daniel_Dog]

This is due to thin provisioning.

The VM disk will only take up as much space as it needs for its data on the disk.
See: https://pve.proxmox.com/wiki/Storage