[ovirt-users] Re: Sparse VMs from Templates - Storage issues
Hi Nir,
Just to report.
As suggested, I created a Posix compliant storage domain with CephFS
and copied my templates to CephFS.
Now I created VMs from CephFS templates and the storage error happens again.
As I understand, the storage growth issue is only on iSCSI.
Am I doing something wrong?
Kind regards,
Shantur
On Wed, Aug 11, 2021 at 2:42 PM Nir Soffer <nsoffer(a)redhat.com> wrote:
>
> On Wed, Aug 11, 2021 at 4:24 PM Arik Hadas <ahadas(a)redhat.com> wrote:
> >
> >
> >
> > On Wed, Aug 11, 2021 at 2:56 PM Benny Zlotnik <bzlotnik(a)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
> >
> >
> > +1
> > 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
>
> I was referring to transient disks - created in vdsm:
>
https://github.com/oVirt/vdsm/blob/45903d01e142047093bf844628b5d90df12b6f...
>
> This creates a *local* temporary file using qcow2 format, using the
> disk on shared
> storage as a backing file.
>
> Maybe this is not used by engine?
>