IBM z13s, Technical Manual

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IBM z13s Technical Guide
IRD has the following characteristics:
򐂰 IRD processor management: WLM dynamically adjusts the number of logical processors
within an LPAR and the processor weight based on the WLM policy. The ability to move
the processor weights across an LPAR cluster provides processing power where it is most
needed, based on WLM goal mode policy.
The processor management function is automatically deactivated when HiperDispatch is
active. However, the LPAR weight management function remains active with IRD with
HiperDispatch. For more information about HiperDispatch, see 3.7, “Logical partitioning”
on page 116.
HiperDispatch manages the number of logical CPs in use. It adjusts the number of logical
processors within an LPAR to achieve the optimal balance between CP resources and the
requirements of the workload.
HiperDispatch also adjusts the number of logical processors. The goal is to map the
logical processor to as few physical processors as possible. This configuration uses the
processor resources more efficiently by trying to stay within the local cache structure.
Doing so makes efficient use of the advantages of the high-frequency microprocessors,
and improves throughput and response times.
򐂰 Dynamic channel path management (DCM): DCM moves FICON channel bandwidth
between disk control units to address current processing needs. z13s servers support
DCM within a channel subsystem.
򐂰 Channel subsystem priority queuing: This function on the z13, z13s, and z Systems
servers allow the priority queuing of I/O requests in the channel subsystem and the
specification of relative priority among LPARs. When running in goal mode, WLM sets the
priority for an LPAR and coordinates this activity among clustered LPARs.
For more information about implementing LPAR processor management under IRD, see z/OS
Intelligent Resource Director, SG24-5952.