Comment 4 for bug 1057719

Reviewed: https://review.openstack.org/14061
Committed: http://github.com/openstack/nova/commit/0af4dd0120270592e02d3afa1be278a834bf470a
Submitter: Jenkins
Branch: stable/folsom

commit 0af4dd0120270592e02d3afa1be278a834bf470a
Author: Vishvananda Ishaya <email address hidden>
Date: Thu Sep 27 12:32:32 2012 -0700

    libvirt: Improve the idempotency of iscsi detach

    When detaching an iscsi volume it is possible for the iscsi commands
    to run concurrently, causing a target to be deleted by one greenthread
    while the other is continuing. When removing the iscsi connection,
    we should always ignore exit code 21 because that means that the
    target has already been removed.

    Fixes bug 1057719

    Change-Id: I0c9f2623f85a817e2be506f9a6d523d45c76848a