'Failover to replication target.'

def failover_host(self, context, volumes, secondary_id=None, groups=None):

    LOG.info('RBD    driver    failover    started.')
    if (not self._is_replication_enabled):
        raise exception.UnableToFailOver(reason=_('RBD:    Replication    is    not    enabled.'))
    if (secondary_id == 'default'):
        replication_status = fields.ReplicationStatus.ENABLED
    else:
        replication_status = fields.ReplicationStatus.FAILED_OVER
    (secondary_id, remote) = self._get_failover_target_config(secondary_id)
    demotion_results = self._demote_volumes(volumes)
    updates = [self._failover_volume(volume, remote, is_demoted, replication_status) for (volume, is_demoted) in zip(volumes, demotion_results)]
    self._active_backend_id = secondary_id
    self._active_config = remote
    LOG.info('RBD    driver    failover    completed.')
    return (secondary_id, updates, [])
