[Engine-devel] VM Payload feature

[David Lutterkort]

On Mon, 2012-02-27 at 21:17 +0200, Itamar Heim wrote:
> On 02/27/2012 09:14 PM, David Lutterkort wrote:
> > On Mon, 2012-02-27 at 18:22 +0200, Itamar Heim wrote:
> >> On 02/27/2012 05:45 PM, Dan Kenigsberg wrote:
> >>> On Mon, Feb 27, 2012 at 04:19:02PM +0200, Shahar Havivi wrote:
> >>>> 
> >>> Let's re-ask the question about the (Engine) API: Do we need the payload
> >>> to be passed on VM definition? Or is it enough to pass it on VM startup?
> >>
> >> my view is vm definition, not only startup.
> >
> > For a cloud, you generally want to launch multiple VM's off the same
> > image, and therefore need to be able to specify the user data for each
> > VM. Whether that happens when you define or launch the VM isn't all that
> > important, though it would be a little friendlier to users to do it at
> > VM start, since they then do not need to have the user data ready (or
> > know it) when they define a VM.
> 
> well, true for cloud when image start is also creating the instance, 
> while in ovirt, at least for now, you need to create the VM then launch it.
> i agree you need to be able to pass this at VM start, but considering VM 
> are mostly stateful, i don't see why you wouldn't let user persist this 
> like the VM is presistent.

The point I was making is that for cloud you want a notion of an image
(template) that's one-to-many with the VM's launched off of it, no
matter whether the VM's themselves are stateful or stateless. The
important thing is that user data is associated to the VM, not the
image/template.

David