[Ovirt-devel] VM Installation problem (and proposed solution)

Chris Lalancette clalance at redhat.com
Fri Aug 29 06:08:04 UTC 2008

Daniel P. Berrange wrote:
> On Thu, Aug 28, 2008 at 05:20:06PM +0200, Chris Lalancette wrote:
>> Hello all (Ian especially),
>>      apevec pointed out a problem with installation of guests under oVirt.  What
>> currently happens is that after you finish the installation of (say) Fedora in a
>> VM, the VM reboots, but then immediately PXE boots again.  This is because we
>> haven't killed the guest and re-defined the XML to have the boot device be the
>> hard drive, like it should.
> You don't have to wait for installation to finish before re-defining the 
> XML with hard drive as the boot device
> You can define the post-install XML config the moment the guest has booted.
> When it shuts down, libvirt will automatically switch over to the newly
> defined config.  This is how virt-install handles it.

Yes, true.  The difference is because of the asynchronous nature of taskomatic,
we basically kick off the guest on the node, and then go on to do other things.
 The next time we would hear anything about this guest is when host-status
eventually polled it and noticed it "shutoff" (even though we think it is
running).  So then we would need to perform the heuristic of "if this was
install time, and the guest is now dead, restart it".  Just doing all of this
out on the node will reduce our round-trips to the server, and do the whole
thing in a more timely fashion.  That's why I think it is better to do this
whole thing remotely on the node.

Chris Lalancette

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