xen resize with volumes fails pv not loaded

[Cory Stone]

We see this with windows guests.

When doing a resize with cinder volumes attached, the vm is first started, then the volumes are attempted to be hotplugged in. The windows guests haven't actually loaded the PV drivers yet, which causes self.driver.finish_migration() in compute/manager to fail. Xen throws a MISSING_PV_DRIVERS error when trying to attach.

[Cory Stone (corystone)]

The suggested fix (from ant & comstud) was to modify the xen driver to attach the volumes before vm start and not attempt to hot plug them. I'll submit a patch that does this.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/18730

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/18730
Committed: http://github.com/openstack/nova/commit/21ea2e6109831156592dd1e4f4f4caefdcedd04f
Submitter: Jenkins
Branch: master

commit 21ea2e6109831156592dd1e4f4f4caefdcedd04f
Author: Cory Stone <email address hidden>
Date: Fri Dec 28 15:39:54 2012 -0600

    xenapi: Avoid hotplugging volumes on resize.

    In finish_migration, instead of starting up the vm and then
    hotplugging in the volumes to it, just attach the volumes before
    starting the vm.

    This avoids the issue where the guest OS hasn't loaded the PV
    drivers for the volume yet.

    Fixes bug 1094351

    Change-Id: I51d754f8f82f1d22bc123b39777449b58b03e389