A company has deployed multiple block service applications on a Huawei scale-out storage system.

The SmartQoS section explicitly states that upper-limit control can “limit the IOPS, bandwidth, and latency.” Therefore, A, C, and D are correct.

IOPS controls the number of I/O operations that a workload can issue within a given period. Bandwidth controls the quantity of data transferred per unit of time. Latency control provides an I/O response-time objective so that resource contention can be managed while protecting service quality.

For OceanStor Pacific block services, Huawei implements distributed SmartQoS with volume I/O queues and token buckets. The course explains that when IOPS is restricted, one I/O consumes one token; when bandwidth is restricted, one byte consumes one token. The token rate is coordinated among VBS nodes to enforce the overall performance objective of a volume.

Option B, OPS, is not identified as one of the SmartQoS performance-control indicators in this section. The defined indicators are IOPS, bandwidth, and latency.

Study Guide Topics: Data Storage Technology Presentation → OceanStor Pacific → SmartQoS → Block Service → Distributed Traffic Control → IOPS/Bandwidth/Latency.