Comment 2 for bug 1801772

Reviewed: https://review.openstack.org/618127
Committed: https://git.openstack.org/cgit/openstack/stx-config/commit/?id=907f8de09ede32d24da677af90a2de4abbe7353f
Submitter: Zuul
Branch: master

commit 907f8de09ede32d24da677af90a2de4abbe7353f
Author: Ovidiu Poncea <email address hidden>
Date: Wed Nov 14 17:26:00 2018 +0200

    Fix Ceph split brain on multinode

    Due to changes that make Ceph work on 1 node configuration
    'mon_initial_members = controller-0' was added to /etc/ceph.conf.
    This settings allows ceph to work with a single monitor. On
    multinode it may cause brain split as controller-0 may start by
    itself if it is not able to immediately connect to the good cluster.

    This will also cause problems at Backup & Restore when controllers
    are reinstalled but older ceph cluster is recovered. In this case
    valid monitor data present on storage-0 is downloaded by the monitor
    on controller-0. Problem is that if mon_initial_members = controller-0
    then the monitor on controller-0 will be happy to start by itself and
    will not download the valid data from storage-0 leading to a possible
    brain split condition.

    This commit sets this option for 1 node configuration only and
    keeps it undef for multinode.

    Change-Id: I01d5563260ad211b04fe4904c32f255f4e683b07
    Closes-bug: 1801772
    Signed-off-by: Ovidiu Poncea <email address hidden>