---
upgrade:
  - |
    The tripleo::profile::base::cinder::volume::rbd::cinder_rbd_backend_host
    default value has changed, and no longer defaults to "hostgroup" when
    other hiera variables (cinder::backend_host and cinder::host) are
    undefined. This ensures cinder's RBD backend_host is only set for
    pacemaker (HA) deployments, when tripleo-heat-templates sets
    cinder::backend_host to "hostgroup".

    When upgrading an existing non-HA deployment, the old "hostgroup" default
    value can be preserved by assigning the hiera variable
    tripleo::profile::base::cinder::volume::rbd::cinder_rbd_backend_host.
    New non-HA deployments should leave this variable unset.