'Retrieve stats info from volume group.'

def _update_volume_stats(self):

    LOG.debug('Updating    volume    stats')
    data = {}
    backend_name = self.configuration.safe_get('volume_backend_name')
    storage_protocol = ('iSER' if self.configuration.safe_get('zadara_use_iser') else 'iSCSI')
    data['volume_backend_name'] = (backend_name or self.__class__.__name__)
    data['vendor_name'] = 'Zadara    Storage'
    data['driver_version'] = self.VERSION
    data['storage_protocol'] = storage_protocol
    data['reserved_percentage'] = self.configuration.reserved_percentage
    data['QoS_support'] = False
    (total, free) = self._get_pool_capacity(self.configuration.zadara_vpsa_poolname)
    data['total_capacity_gb'] = total
    data['free_capacity_gb'] = free
    self._stats = data
