IBM z/OS - page 37

• 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

ICB-4 (2.0 GBps)

ICB-3 (1 GBps)

ICB-2 (333 MBps)

z990

z90

z80

G5/G6

STI

I/O Cage

STI-3

MUX

STI-2

MUX

4 x 2.0 GBps

STIs

4 x 2 GB/s

STI

I/O Cage

STI-3

MUX

STI-3

MUX

STI

LPAR Cluster

z/OS

Linux

OS/390

ICF