Re: [Qemu-devel] [RFC] More robust migration

[Paul Brook <paul@codesourcery.com>]

On Monday 23 February 2009, Jamie Lokier wrote:
> Paul Brook wrote (about resuming snapshots on a different QEMU):
> > I'm not saying it's a useless feature, just that it's very extremely
> > to do reliably, and for that reason unlikely to happen. An
> > unreliable implementation (i.e. one that claims to migrate/snapshot,
> > then breaks some of the time) is IMHO worse than nothing.
>
> Well, one which cannot resume from a snapshot at all unless you have
> the original host and original QEMU/KVM around is pretty bad.

I never said you need the same host. All the save/restore code should be host 
independent. It should be possible to save state on (say) i386 and restore on 
ppc64. Anything that prevents this is IMO a bug.

For KVM you're likely to need a cpu with at least as many features as the old 
one, but that's the price you pay for using host hardware features.

However different versions of qemu (i.e. qemu built from different sources) 
are a different question altogether. If you can't reproduce your old qemu 
binaries you have much larger problems.

Paul