[SOLVED] cannot take snapshot: local ZFS uses raw for vdisks / cannot change to qcow

[Martin.B.]

I created a small PVE cluster with local ZFS.
After creating a few VMs and trying to take a snapshot, i discovered that all VM disks are created as raw and do not support snapshots.
Searching how i can resolve this but i do not have "the" answer.
I found an option for "Default image format" in storage.cfg and at creation time of VM, disk format could be selected. Well i cannot select the disk format.
I found some information on how to change disk format by moving the vdisk, but i have no choice to store it as "qcow2" on the localZFS storage. What seems to be normal, according to different ressources, cause ZFS is block storage not file level.
According to the storage table https://pve.proxmox.com/wiki/Storage#_storage_types local ZFS does support snapshots, but i think this is referring to ZFS snapshots?

As i am getting really confused. So how do i take a snapshot of a single VM stored on localZFS, maybe even multiple snapshots (snapshot chain)?
If this means recreating the ZFS storage and the VMs: no problem. I just need the snapshot feature for testing.
If ZFS does not support this: ok. Which filesystem shall i use for local storage to get that working? I can use raid level on the controller level and go without the ZFS replication. But testing without snapshots is a pain in the a..

 

[d.oishi]

local-zfs uses the zfspool backend, so VM disks are stored as ZFS volumes/datasets in raw format. Not being able to select qcow2 there is expected.
Snapshots on local-zfs are not qcow2 internal snapshots; they are provided by the ZFS storage backend itself.
So yes, you can take snapshots of a VM on local ZFS, including multiple snapshots.
If you specifically need qcow2 images, you need a file-based storage such as Directory or NFS.

https://pve.proxmox.com/wiki/Storage:_ZFS

 

[gasherbrum]

click the snapshots tab, then click take snapshot

 

[Impact]

ZFS definitely supports this and is a great choice. Please share this and we can figure out why it doesn't work for you

cat /etc/pve/storage.cfg
qm config VMIDHERE

 

[Martin.B.]

Thanks you all for the fast comments.
I could not start a snapshot in the GUI, the button "Take snapshot" was greyed out every time i tried.

The problem was, as often, sitting in front of the keyboard.... and now i feel really bad.
I just copy/pasted the Snapshot name from my document i write while testing and named it as always (being used VMWare) containing Date and Time. Looks like Proxmox does not like special characters or whitespaces in the name. i think we will have to switch naming and better use the description.

Sorry for this unnecessary thread.