'Retrieves stats info from volume group.'

def _update_volume_stats(self):

    data = {}
    backend_name = self.configuration.safe_get('volume_backend_name')
    data['volume_backend_name'] = (backend_name or self.VENDOR)
    data['vendor_name'] = self.VENDOR
    data['driver_version'] = self.get_version()
    data['storage_protocol'] = self.driver_volume_type
    self._ensure_shares_mounted()
    self._initiate_image_cache_cleanup()
    pools = []
    for share in self._mounted_shares:
        pool = dict()
        (capacity, free, used) = self._get_capacity_info(share)
        pool['pool_name'] = share
        pool['total_capacity_gb'] = (capacity / float(units.Gi))
        pool['free_capacity_gb'] = (free / float(units.Gi))
        pool['reserved_percentage'] = 0
        pool['QoS_support'] = True
        pools.append(pool)
    data['pools'] = pools
    self._stats = data
