Defining zIIPs

You can define a logical partition to use one or more zIIPs and/or zAAPs with either of the following combinations:

• One or more dedicated general purpose CPs and one or more dedicated zIIPs/zAAPs
• One or more shared general purpose CPs and one or more shared zIIPs/zAAPs

The mode specified for the logical partition must be set to ESA/390 to allow for the definition of zIIPs or zAAPs to the logical partition.

Futhermore, there are the following requirements regarding zIIPs and standard CPs:

• The number of zIIPs must not exceed the number of standard CPs on a server.
• You must have at least one standard CP defined for a partition. The z/OS® system needs at least one standard CP online at all times.
• You can set the number of zIIPs for an LPAR, and each processor pool (for example, CPs and zIIPs) can be assigned a unique weight when the processors are being shared.
• There is hard capping for zIIPs, but there is no support of defined capacity (which is the WLM support for 4-hour rolling average). The existing single set of PR/SM logical partition processor weights (INITIAL, MIN, MAX) are applied independently to the shared standard CPs — capping only applies to shared standard CPs configured to the logical partition. If you use WLM weight management for the LPAR with SCRT, then z/OS WLM manages shared standard CPs as today, but not the zIIPs.
• zIIPs do not participate in Intelligent Resource Director. zIIPs do not participate in dynamic share management or in the number of logical zIIPs online.