Comment 6 for bug 1200040

Reviewed: https://review.openstack.org/36612
Committed: http://github.com/openstack/cinder/commit/dbb854635fdb988e28acf87d221fa278e6cb8c0c
Submitter: Jenkins
Branch: master

commit dbb854635fdb988e28acf87d221fa278e6cb8c0c
Author: xiaoxi_chen <email address hidden>
Date: Thu Jul 11 15:22:04 2013 +0800

    Check enabled backup service before rpc request

    In previous code we didn't check whether we have an enabled
    backup service there before we send out the rpc request,
    results that if no enabled backup service there,the volume will
    stays in "backing-up" state and the backup will stays in "creating".

    This patch fixed this issue, we exam whether at least an appropriate
    (same host,az as the volume and is_alive) backup service available
    before we do the rpc request.

    Fixes: bug #1200040
    Change-Id: I77154528f489ed20f7b784e6fcefccf15dc81d1d