On Wed, Aug 11, 2021 at 2:56 PM Benny Zlotnik <bzlotnik@redhat.com> wrote:
> If your vm is temporary and you like to drop the data written while
> the vm is running, you
> could use a temporary disk based on the template. This is called a
> "transient disk" in vdsm.
> Arik, maybe you remember how transient disks are used in engine?
> Do we have an API to run a VM once, dropping the changes to the disk
> done while the VM was running?

I think that's how stateless VMs work

It doesn't work exactly like Nir wrote above - stateless VMs that are thin-provisioned would have a qcow volume on top of each template's volume and when they starts, their active volume would be a qcow volume on top of the aforementioned qcow volume and that active volume will be removed when the VM goes down
But yeah, stateless VMs are intended for such use case