Changing the max size of the shared processor pool

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For an LPAR that is configured with the Shared processing mode setting, the maximum (max) size of the shared processor pool (SSP) can be a physical limit for PowerHA® SystemMirror®.

About this task

To authorize PowerHA SystemMirror to dynamically adjust the max size of the SSP, complete the following steps:

Procedure

  1. From the command line, enter smit sysmirror
  2. From the SMIT interface, select Cluster Applications and Resources > Resources > Configure User Applications (Scripts and Monitors) > Resource Optimized High Availablity > Change/Show Default Cluster Tunables, and press Enter.
  3. In the Adjust Shared Processor Pool size if requested field, specify yes.
  4. Verify and synchronize the cluster.

What to do next

PowerHA SystemMirror can dynamically change the max size of a SSP. The SSP are typically used with third-party software that requires a license that charges on a per-processor basis. For example, if you pay for 7 CPU Oracle licenses and if you have 6 CPUs on the active CEC with one CPU on the backup CEC, when a failover occurs and the takeover process starts, you expect the shared processor pool size to be identical on the new CEC that is used due to the takeover. PowerHA SystemMirror, as part of the resource release process, decreases the size of the SSP to its original size on the active node and increases the size of the SSP to the expected size on the standby node. This process verifies that your Oracle applications are still contained on the same number of CPUs than before the takeover (6 CPUs on the new active node and 1 CPU on the previously active node).