[Ovirt-devel] QCOW2 image support?

[Daire Byrne]

Perry,

----- "Perry Myers" <pmyers at redhat.com> wrote:

> > I'm aware that oVirt uses Cobbler to setup and configure new images but
> > is it also possible to create and configure a VM image and then use it
> > as a "golden" image to create multiple copies? I'm thinking along the
> > lines of using QCOW2's ability to create new COW images (qemu-img
> > create -b) but referencing the common read-only "golden" image. If this
> > is not currently possible are there any plans for this kind of
> > functionality? Using Cobbler and kickstart is nice and all but
> > sometimes you just want to configure a VM image on your desktop machine
> > (say) by hand and then be able to clone it many times instead of
> > writing and maintaining kickstart scripts. Obviously Windows
> > installations particularly benefit from this approach.
> 
> Cobbler can do this via the Cobbler image object.  We don't have
> support for 'golden' images in oVirt Server yet, but it is certainly on the 
> roadmap.  Adding support for this should be relatively easy since most
> of the groundwork for adding this was done when we added support for
> using Cobbler ISO images.  (Patches welcome, as always!)

Cool. Good to know - thanks.

> I also believe that libvirt functionality for snapshots would be
> required here as well, and I think that is already in libvirt so hopefully we 
> should just be able to use that.  Probably the most challenging piece
> would be modifying the db model to track the snapshots.  (Scott you
> have any thoughts on this?)

I'm not too bothered about snapshotting running machines (although that 
would be cool too) so much as the initial creation of a COW image using
the golden image as a common read-only base. Basically it would be great
if oVirt could use all the qemu-img functionality.
 
> > Also on an unrelated note is oVirt going to be part of the "Enterprise
> > Virtualization Manager for Servers" mentioned in Redhat's recent press
> > release?
> 
> oVirt is a project developing virtualization management technology on
> Fedora.  As some parts of Fedora feed into RHEL, some parts of oVirt
> may feed into RHEL virtualization in the future.

Okay, thanks. Maybe the press release is talking more about the 
Qumranet solutions that were acquired. Are there plans to give oVirt 
the ability to schedule and migrate machines based on load etc. or will 
this be managed by a separate system (via libvirt)? Is oVirt only
supposed to be used for used the initial provisioning?

Regards,

Daire