IBM z/OS manual Intelligent Resource Director, IRD Scope

•ICB-3. The Integrated Cluster Bus-3 is used to provide high-speed coupling communication between a z990 server or CF and a z800/z900 server or CF or between two z800/z900s over short distances (~7 meters). For longer distances, ISC-3 links must be used. The z990 features the STI-3 card which resides in an I/O cage and provides 2 ICB-3 ports each capable of up to 1 GBps. The ports are activated in one port increments. Up to 8 STI-3 cards, 16 ICB-3 links are available on the z990. ICB-3 links operate in “Peer Mode.”

•ICB-4. The Integrated Coupling Bus-4 is a “native” cou- pling connection available for connecting a z990 server or CF to another z990 server or CF over short distances. Capable of up to 2.0 GBps, the ICB-4 is the fast external coupling connection available for the z990. The ICB-4 connection consists of one link that directly attaches to an STI port on the system and does not require connec- tivity to a card in the I/O cage. One feature is required for each end of the link. Up to 16 ICB-4 features can be confi gured on a z990 depending on model selected.

•IC. The Internal Coupling channel emulates the Cou- pling Links providing connectivity between images within a single server. No hardware is required, however a minimum of 2 CHPID numbers must be defi ned in the IOCDS. IC links provide the fastest Parallel Sysplex con- nectivity

Intelligent Resource Director

Exclusive to IBM’s z/Architecture is Intelligent Resource Director (IRD), a function that optimizes processor and channel resource utilization across Logical Partitions (LPARs) based on workload priorities. IRD combines the strengths of the zSeries LPARs, Parallel Sysplex clustering, and z/OS Workload Manager.

Intelligent Resource Director uses the concept of an LPAR cluster, the subset of z/OS systems in a Parallel Sysplex cluster that are running as LPARs on the same zSeries server. On a z990, systems that are part of the same LPAR cluster may be in different LCSSs. In a Parallel Sysplex environment, Workload Manager directs work to the appropriate resources based on business policy. With IRD, resources are directed to the priority work. Together, Parallel Sysplex technology and IRD provide fl exibility and responsiveness to on demand e-business workloads that is unrivaled in the industry.

IRD has three major functions: LPAR CPU Management, Dynamic Channel Path Management, and Channel Sub- system Priority Queuing.

IRD Scope

	STI	STI-3
M	STI
		MUX
B
	STI
A
	STI	STI-2
4 x 2.0 GBps		MUX
	STIs	I/O Cage

ICB-4 (2.0 GBps)

z990

ICB-3 (1 GBps)

ICB-3 (1 GBps)z900

z800

ICB-2 (333 MBps)

ICB-2 (333 MBps)

G5/G6

LPAR Cluster

z/OS

z/OS

Linux

OS/390

ICF

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