Comment 4 for bug 1055715

Reviewed: https://review.openstack.org/13674
Committed: http://github.com/openstack/nova/commit/076cb9d98330ae1ead94cc4d2c08b27939752648
Submitter: Jenkins
Branch: milestone-proposed

commit 076cb9d98330ae1ead94cc4d2c08b27939752648
Author: Vishvananda Ishaya <email address hidden>
Date: Tue Sep 25 11:15:14 2012 -0700

    Fix issues with device autoassignment in xenapi

    This is a workaround for two issues in xenapi. The first is that
    does not set the instance default_root_device to /dev/xvda so it
    defaults to /dev/sda. The proper fix for this involves setting the
    default_root_device in xenapi and a db migration to set the proper
    default_root_device for existing instances.

    This patch works around this issue by explicitly setting the prefix
    to /dev/xvd if the compute driver is xenapi.

    The second issue is that xenapi never updates the instance record
    to include default_swap_device and default_ephemeral device. The
    fix for this involes adding the appropriate update to the instance
    record and a migration that sets the proper values for all existing
    instances.

    This patch works around this issue by explicily checking the
    instance_type and removing the devices from the list if the compute
    driver is xenapi.

    Fixes bug 1055715 and bug 1055712

    Change-Id: I61aa15e69eb0a22430bb22ea5149b1f0735b3328
    (cherry picked from commit 69564763960cddc249138469811a0a771db16e19)