'Disconnect the volume.
:param connection_info: dict of connection information for the backend
storage when a connection was initiated with Cinder.
:param disk_dev: The block device mountpoint device name (not path).
This is currently not used by this method.
:param instance: The nova.objects.Instance that is having a volume
disconnected from it.'

def disconnect_volume(self, connection_info, disk_dev, instance):

    LOG.debug('Calling    os-brick    to    detach    DRBD    Volume.', instance=instance)
    self.connector.disconnect_volume(connection_info['data'], None)
    LOG.debug('Disconnected    DRBD    Volume    %s', disk_dev, instance=instance)
