IBM eServer zSeries 900 Technical Guide

68 IBM eServer zSeries 900 Technical Guide

Table 2-16 shows the STI pluggings with two compatibility I/O cage installed.

Table 2-16 Compatibility I/O cage secondary STI plugging (upgrades or RPQ)

This configuration uses only three out of the four STI-H card ports. The fourth port cannot be

used to connect ICB connections. The mixing of ICB FC 0992 and STI connections to I/O

cages FC 2022 from the same STI-H card is not supported.

2.6.6 Channels to SAP assignment

For the 9672 G5/G6 models, the channel-to-STI assignment was performed on an STI basis.

All the channels on an STI were supported by the same SAP, and the installed STIs were

spread across the available SAPs.

For z900, you should not be concerned with configuring for SAP affinity. In a z900 model the

assignment of a channel to a SAP is “channel card” by type balanced. The algorithm takes

the channel type that has the highest number of channel cards and spreads these (from

different I/O domains) as evenly as it can among the available SAPs. Then it takes the

channel card that has the next highest number of installed cards. Again these are evenly

divided and again spread among the SAPs, starting at the SAP (or SAPs) that has the least

number of supported channel cards. This is repeated until all the channel cards are assigned

to supporting SAPs. This assignment is performed at activation time (Power On Reset).

During concurrent installation of new channel cards, this process is only performed for the

newly added channel cards.

Table 2-17 provides an example of the z900 channel-to-SAP assignment process.

Table 2-17 Channels-to-STI assignment example

The z900 standalone coupling facility model 100 and the z900 general purpose models 101

to 109 have two SAPs. These models can be ordered with up to three additional SAPs

depending on your requirements and on availability of spare PUs left on the 12-PU MCM.

The z900 models 1C1 to 1C9, 110 to 116, 2C1 to 2C9, and 210 to 216 have three SAPs.

These models can be ordered with up to five additional SAPs depending on your

requirements and on availability of spare PUs left on a 20-PU MCM.

Card count Compatibility I/O cage (Z bottom) Compatibility I/O cage (Z top)

Domain 0Domain 1Domain 2Domain 0Domain 1Domain 2

120.0

2-16 20.0 22.0

17-22 20.0 22.0 22.1

23-44 20.0 20.1 20.2 22.0 22.1 22.2

Number of

cards

Channel

types

First SAP Second

SAP

Third SAP

14 FICON554

10 ESCON-16 3 3 4

6 OSA-E 2 2 2