QoS classification

QoS in IBM Storage Scale can be classified into two categories, which are system QoS via system classes, and user QoS via user-defined classes.

QoS system classes

The system classes limit the impact of long-running, I/O-intensive IBM Storage Scale maintenance commands by preventing them from monopolizing storage pool I/O. These QoS classes enable maintenance activities to run concurrently with normal workloads without degrading user-initiated I/O.

For more information, see System classes and Workflow for QoS system classes.

QoS user classes

The user classes provide flexible control over I/O access at the fileset level, enabling differentiated I/O tiering for organizational groups such as departments, projects, or teams. In addition, this QoS classes make it possible to configure an aggregate I/O limit at the filesystem-pool level, which help ensure predictable and balanced resource usage.

For more information, see User classes: fileset-level QoS and Workflow for QoS user classes.