'Retrieve stats info from volume group.'

def _update_volume_stats(self):

    LOG.debug('Updating    volume    stats.')
    data = {}
    data['vendor_name'] = 'IBM'
    data['driver_version'] = self.VERSION
    data['storage_protocol'] = self.protocol
    data['pools'] = []
    backend_name = self.configuration.safe_get('volume_backend_name')
    data['volume_backend_name'] = (backend_name or self._state['system_name'])
    data['pools'] = [self._build_pool_stats(pool) for pool in self._get_backend_pools()]
    if self._replica_enabled:
        data['replication'] = self._replica_enabled
        data['replication_enabled'] = self._replica_enabled
        data['replication_targets'] = self._get_replication_targets()
    self._stats = data
