Quality of service

You can set upper bounds on quality of service by assigning specific physical resources to each access zone.

Quality of service addresses physical hardware performance characteristics that can be measured, improved, and sometimes guaranteed. Characteristics that are measured for quality of service include but are not limited to throughput rates, CPU usage, and disk capacity. When you share physical hardware in a PowerScale cluster across multiple virtual instances, competition exists for the following services:
  • CPU
  • Memory
  • Network bandwidth
  • Disk I/O
  • Disk capacity

Access zones do not provide logical quality of service guarantees to these resources, but you can partition these resources between access zones on a single cluster. The following table describes a few ways to partition resources to improve quality of service:

Use Notes
NICs You can assign specific NICs on specific nodes to an IP address pool that is associated with an access zone. By assigning these NICs, you can determine the nodes and interfaces that are associated with an access zone. This enables the separation of CPU, memory, and network bandwidth.
SmartPools SmartPools are separated into multiple tiers of high, medium, and low performance. The data written to a SmartPool is written only to the disks in the nodes of that pool.

Associating an IP address pool with only the nodes of a single SmartPool enables partitioning of disk I/O resources.

SmartQuotas Through SmartQuotas, you can limit disk capacity by a user or a group or in a directory. By applying a quota to an access zone's base directory, you can limit disk capacity that is used in that access zone.