You can monitor QoS performance with predefined analytics reports, which can be found under Predefined Analytics in the Analytics -> Analytics page in the VAST Web UI:
Click the User category and run the User QoS report to view QoS analytics per user, including the following metrics:
IOPS
Bandwidth
QoS wait time (the amount of time the user's request was waiting for processing due to applicable QoS policies)
Latency
Click the View report category and run QoS average wait time report to view QoS average wait time per view.