'Return size of volume to be managed by manage_existing.
When calculating the size, round up to the next GB.'

def manage_existing_get_size(self, volume, existing_ref):

    LOG.debug('manage_existing_get_size    volume    id=%(volume_id)s    existing_ref    source    id=%(source_id)s', {'volume_id': volume['id'], 'source_id': existing_ref['source-id']})
    return self.common.manage_existing_get_size(volume, existing_ref)
