'Save base volume metadata to container.
This will fetch all fields from the db Volume object for volume_id and
save them in the provided container dictionary.'

def _save_vol_base_meta(self, container, volume_id):

    type_tag = self.TYPE_TAG_VOL_BASE_META
    LOG.debug("Getting    metadata    type    '%s'", type_tag)
    meta = self.db.volume_get(self.context, volume_id)
    if meta:
        container[type_tag] = {}
        for (key, value) in meta:
            if (not self._is_serializable(value)):
                LOG.info("Unable    to    serialize    field    '%s'    -    excluding    from    backup", key)
                continue
            if ((key is 'encryption_key_id') and (value is not None)):
                km = key_manager.API(CONF)
                value = km.store(self.context, km.get(self.context, value))
                LOG.debug('Copying    encryption    key    UUID    for    backup.')
            container[type_tag][key] = value
        LOG.debug("Completed    fetching    metadata    type    '%s'", type_tag)
    else:
        LOG.debug("No    metadata    type    '%s'    available", type_tag)
