Re: Re: [PATCH] qemu-xen: Fix PV segfault

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Jul 02, 2008 at 05:28:45PM +0200, Stefan de Konink wrote:
> Ian Jackson schreef:
> >Stefan de Konink writes ("Re: [Xen-devel] Re: [PATCH] qemu-xen: Fix PV 
> >segfault"):
> >>But this isn't the case now at all, is it? I name xenstored; is the move 
> >>that Samuel with minios takes a way to solve this?
> >
> >xenstored is not critical to the run-time operation of PV domains.
> >Without it you can't boot, add devices, etc. etc.  But you can (for
> >example) shut down a PV domain cleanly.
> 
> So the actual 'problem' is the storage of the domain properties, 
> preferably in a 'process' that is not running, but an API that can query 
> it. I think Libvirtd fails on that point too, everything gets fubar, 
> once a daemon breaks. The reason for a running daemon providing domain 
> specific information is not clear for me, storing it on disk will always 
> give better recovery possibilities.

That is just an artifact of libvirt being written to work with all QEMU
versions back to 0.8.1, which didn't have a good way to re-connect to
the monitor of a running VM. Its on the TODO list to automatically use
a UNIX socket for monitor communication when we detect QEMU >= 0.9.x
so there's no need for libvirt  be the direct parent of the QEMU processes

Daniel
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