[libvirt] [PATCH] qemu: Do not unlink managedsave image if restoring fails.

[Jiri Denemark]

On Tue, Apr 05, 2011 at 14:47:22 +0800, Osier Yang wrote:
> Both "qemuDomainStartWithFlags" and "qemuAutostartDomain" try to
> restore the domain from managedsave'ed image if it exists (by
> invoking "qemuDomainObjRestore"), but it unlinks the image even
> if restoring fails, which causes data loss.
> 
> However, I'm not sure if it's the very correct way to fix it,
> if restoring fails, and we didn't remove the image, it will
> trys to restore from the image again next time, if that's
> not the user expected (e.g. the user made quite many changes
> on the guest), then it's a new problem.

I think this patch is risky. You should either remove the state on error
(which is the current state) or fail domain start if managed state is present
but resuming from it fails. If you do something in the middle (your patch) you
will certainly end up corrupting domain's disks.

Jirka