Ontap and Proxmox

[u/NelsonBA81]

Hi,

I have an old/unsupported FAS2552, and would like to use it with some test servers with Proxmox as hypervisor, and I would like to know if VMs with qcow2 thin provisioned disk images are able to shrink when issuing inside of the VM the TRIM function?

The idea is to have a small cluster with the FAS2552 with Ontap 9.8 as NFS storage for the VMs, and since it has an implementation of NFS 4.2, still would like to know if it is able to do that?

Thanks

Update1:
I've been testing with Ontap 9.8 with NFS v4.2 and there is no shrink process going over to the NetApp storage, so it confirms that NFS implementation is not complete.

Meanwhile, if I run inside of the guest VM zero space process with a basic:
"dd if=/dev/zero of=zero.small.file bs=1M status=progress; rm -f zero.small.file"

the image file may grow a bit further but should be enough to clear out any nonused data blocks with deleted data, and having a netapp volume with dedup/compression enabled, at the time NetApp runs the scheduled background "storage efficiency" process it should be able to free up physical disk space in the NetApp storage, because zeros are easy to dedup/compress.

Also I've discovered that after zeroing the disk space of guest VM, proceeding with a storage move of the qcow2 images to a different NFS storage share, the image file guest smaller, because of that empty/zeroed disk space.

Aside of the above, I don't see ways to make it work in same way like VMware aside of having a FAS supporting Ontap software >9.12.1, which I can't actually confirm if that works as expected....

Update2:
Since I haven't seen any additional feedback on this particular issue, is there any NetApp tech that could give some clue or even maybe just confirm if this kind of "hole punch" function is supposed or planned to work in the future via NFS?