No parameter calibration when create volume qos

I find it when I create a volume qos-specs use the command "openstack volume qos create --consumer front-end --property total_iops_sec_max=2000 test_qos". Then I associate the qos to a volume type and create a volume, which is attach to an instance,However, I found the max value didn't work in the xml file of the instance .After checking the qos,it showed that I have seplt "total_iops_aec_max" as "total_iops_sec_mac".Then I tried to set the value of thr property as "2E3" when create qos,there is no error during createing ,either .If there should be parameter calibration when creating volume qos?