Re: [Qemu-devel] storing machine data in qcow images?

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Eduardo Habkost (ehabkost@redhat.com) wrote:
> On Tue, May 29, 2018 at 03:03:16PM +0100, Dr. David Alan Gilbert wrote:
> > * Richard W.M. Jones (rjones@redhat.com) wrote:
> > > On Fri, May 18, 2018 at 06:09:56PM +0100, Daniel P. Berrangé wrote:
> > > > The closest to a cross-hypervisor standard is OVF which can store
> > > > metadata about required hardware for a VM. I'm pretty sure it does
> > > > not have the concept of machine types, but maybe it has a way for
> > > > people to define metadata extensions. Since it is just XML at the
> > > > end of the day, even if there was nothing official in OVF, it would
> > > > be possible to just define a custom XML namespace and declare a
> > > > schema for that to follow.
> > > 
> > > I have a great deal of experience with the OVF "standard".
> > > TL;DR: DO NOT USE IT.
> > 
> > In addition to the detail below, from reading DMTF's OVF spec (DSP0243 v
> > 2.1.1) I see absolutely nothing specifying hardware type.
> > Sure it can specify size of storage, number of ether cards, MAC
> > addresses for them etc - but I don't see any where specify the type of 
> > emualted system.
> 
> Maybe the VirtualHardwareSection/System/vssd:VirtualSystemType
> element could be used for that.  (DSP0243 v2.1.1, line 650).

Ah yes, you're right; they hadn't bothered putting that in any of the
examples.  A quick search suggests VMWare use that as 'vmx-10' or
'vmx-12' as a 'hardware faimily'.

> But based on Richard's feedback, I think we shouldn't even try to
> use it.

Right; although if we have a key/value system, then if the key/value
structures we used happened to match up with OVMF if they made sense
then I guess it would make conversions easy.

Dave

> -- 
> Eduardo
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK