Configures the server to offload processing to the zIIP engine.

This setting:

• Determines if the zIIP processor is accessible to the LPAR in which a job is running.
• Determines if the server environment has been properly authorized to run a zIIP workload.

Note: If the server determines that the zIIP processor is not accessible or that the environment has not been authorized correctly, it issues a message describing the reason and continues in ZIIP=OFF mode, which forwards all subsequent work to the Central Processor.

Configures the server to either:

• Project what the zIIP usage would be if the server could offload processing to a zIIP, when the server is operating in an LPAR without a zIIP. This requires that the PROJECTCPU parameter be set to YES.

  The SYS1.PARMLIB member IEAOPTxx contains the PROJECTCPU statement. Activating the PROJECTCPU parameter projects zIIP consumption when a zIIP processor is not yet defined to the LPAR. SMF type 30 records will show the potential calculated zIIP time, so that you can accurately project zIIP usage. This enables you to evaluate the effect of configuring a zIIP processor to be available for server usage. The Systems Programmer for your site will have access to this data. Use this option for simulation purposes only.

  Since the zIIP engine actually is not present, all zIIP-eligible workload will be diverted to the Central Processor. Thus, all of that CPU utilization will be recorded in a server variable called &FOCZIIPONCP. This is the amount of workload that would have run on the zIIP engine, and would have appeared in &FOCZIIPCPU, had the zIIP been present and accessible to server work. This information is also recorded in the server job statistics as well as in IBM SMF type 30 records.

  To use this option, insert the following parameter in SYS1.PARMLIB for your LPAR, and also issue the SET ZIIP=ON/SIMMAXZIIP command:

  PROJECTCPU=YES

  This setting:

  • Determines if the PROJECTCPU=YES command has been set in the LPAR.
  • Determines if the server environment has been properly authorized to run a zIIP workload.
• Projects zIIP utilization if 100% of eligible server processing could be offloaded to the zIIP, when the server is running in an LPAR with a zIIP. This lets you determine what you would gain by configuring Workload Manager to give the server a bigger share of zIIP processing.

  IBM Workload Manager (WLM) prioritizes workloads among the Central Processors and zIIP processors at your site based on a complex set of goals and rules established by the system administrator. These rules apply to all workloads from all sources, not just the server. These goals combine to influence the decision to direct server requests to the zIIP engine at any particular moment.

  Utilizing this setting with a zIIP present can help you determine how much advantage you would get if the server had more of a share of the zIIP processor. To see the difference in actual and projected zIIP usage, run the same job with SET ZIIP=ON and then with SET ZIIP=ON/SIMMAXZIIP and compare the results. For more information about evaluating zIIP usage, see Evaluating zIIP Usage.

  This setting:

  • Determines if the zIIP processor is accessible to the LPAR in which a job is running.
  • Determines if the server environment has been properly authorized to run a zIIP workload.

Note: If the server determines that the environment has not been authorized correctly, it issues a message describing the reason and continues in ZIIP=OFF mode, which forwards all subsequent work to the Central Processor.

Configures the server not to offload processing to the zIIP engine. OFF is the default value.

Note: Turn off zIIP enablement only when you know for sure that a job will not gain any advantage from using the zIIP processor or if the system operator or administrator requires that you turn it off.