Comment 8 for bug 1670916

Reviewed: https://review.openstack.org/512643
Committed: https://git.openstack.org/cgit/openstack/ironic-python-agent/commit/?id=bd8c6c7420c5a913ff407da569c1b8dfbc0a488a
Submitter: Zuul
Branch: stable/pike

commit bd8c6c7420c5a913ff407da569c1b8dfbc0a488a
Author: Lucas Alvares Gomes <email address hidden>
Date: Thu Mar 9 14:02:06 2017 +0000

    Fix waiting for target disk to appear

    This patch is changing the _wait_for_disks() method behavior to wait to
    a specific disk if any device hints is specified. There are cases where
    the deployment might fail or succeed randomly depending on the order and
    time that the disks shows up.

    If no root device hints is specified, the method will just wait for any
    suitable disk to show up, like before.

    The _wait_for_disks call was made into a proper hardware manager method.
    It is now also called each time the cached node is updated, not only
    on start up. This is to ensure that we wait for the device, matching
    root device hints (which are part of the node).

    The loop was corrected to avoid redundant sleeps and warnings.

    Finally, this patch adds more logging around detecting the root device.

    Co-Authored-By: Dmitry Tantsur <email address hidden>
    Change-Id: I10ca70d6a390ed802505c0d10d440dfb52beb56c
    Closes-Bug: #1670916
    (cherry picked from commit 3189c16a5e95ade468fa8bc37302eb9979f5a8c9)