'Removes the specified volume from Cinder management.
Does not delete the underlying backend storage object.
The volume will be renamed with "-unmanaged" as a suffix'

@pure_driver_debug_trace
def unmanage(self, volume):

    vol_name = self._get_vol_name(volume)
    unmanaged_vol_name = (vol_name + UNMANAGED_SUFFIX)
    LOG.info('Renaming    existing    volume    %(ref_name)s    to    %(new_name)s', {'ref_name': vol_name, 'new_name': unmanaged_vol_name})
    self._rename_volume_object(vol_name, unmanaged_vol_name)
