alter_tier

Name of the tier to be altered. Must be an existing tier group name: vram, ram, disk[n], persist, cold[n].

Optional parameters. Allowed keys are:

• capacity – Maximum size in bytes this tier may hold at once, per rank.

• high_watermark – Threshold of usage of this tier’s resource that once exceeded, will trigger watermark-based eviction from this tier. The minimum allowed value is ‘0’. The maximum allowed value is ‘100’.

• low_watermark – Threshold of resource usage that once fallen below after crossing the high_watermark, will cease watermark-based eviction from this tier. The minimum allowed value is ‘0’. The maximum allowed value is ‘100’.

• wait_timeout – Timeout in seconds for reading from or writing to this resource. Applies to cold storage tiers only.

• persist – If true the system configuration will be written to disk upon successful application of this request. This will commit the changes from this request and any additional in-memory modifications. Allowed values are:

  • true

  • false

  The default value is ‘true’.

• rank – Apply the requested change only to a specific rank. The minimum allowed value is ‘0’. The maximum allowed value is ‘10000’.

The default value is an empty dict ( ).