[libvirt] KVM processes -- should we be able to attach them to the libvirtd process?

[Daniel P. Berrange]

On Wed, May 06, 2009 at 08:56:18PM +0200, Gerrit Slomma wrote:
> Daniel P. Berrange schrieb:
> >On Tue, May 05, 2009 at 11:38:13PM -0500, Matthew Farrellee wrote:
> >  
> >>It doesn't appear to be the case that the libvirtd daemon can trivially
> >>restart and continue with no interruptions. Right now it loses track of 
> >>VMs.
> >>    
> >
> >That a is a bug then, if you can reproduce it, please file a BZ ticket
> >so we can track it down & fix it.
> >
> >  
> >>In a scenario where VMs are not deployed and locked to specific physical
> >>nodes, it can be highly valuable to have ways to ensure a VM is no
> >>longer running when a layer of its management stops functioning.
> >>    
> >
> >IMHO this is a problem to be solved by clustering software. If the
> >clustering software detects a failure with the management service,
> >then it should power fence the entire node. Relying on management
> >service failure to kill the VMs will never be reliable enough.
> >
> I think he is pointing towards a VM that runs on a host where it isn't 
> defined at via a corresponding *.xml.
> If you restart a libvirt i looses connection to this or these specific 
> VM(s).

That is a bug that needs fixing. Even if there is no persistent config,
we should not loose track of the running VM, because we always write
out the 'live' XML config to /var/run/libvirt explicitly so that it 
is available at restart.

Daniel
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