'Retrieve stats info from volume group.'

def _update_volume_stats(self):

    LOG.debug('Updating    volume    stats.')
    gpfs_base = self.configuration.gpfs_mount_point_base
    data = {}
    backend_name = self.configuration.safe_get('volume_backend_name')
    data['volume_backend_name'] = (backend_name or 'GPFS')
    data['vendor_name'] = 'IBM'
    data['driver_version'] = self.VERSION
    data['storage_protocol'] = 'file'
    (free, capacity) = self._get_available_capacity(self.configuration.gpfs_mount_point_base)
    data['total_capacity_gb'] = math.ceil((capacity / units.Gi))
    data['free_capacity_gb'] = math.ceil((free / units.Gi))
    data['reserved_percentage'] = 0
    data['QoS_support'] = False
    data['storage_pool'] = self._storage_pool
    data['location_info'] = ('GPFSDriver:%(cluster_id)s:%(root_path)s' % {'cluster_id': self._cluster_id, 'root_path': gpfs_base})
    data['consistencygroup_support'] = 'True'
    data['consistent_group_snapshot_enabled'] = True
    if (self._encryption_state.lower() == 'yes'):
        data['gpfs_encryption_rest'] = 'True'
    self._stats = data
