6947ch03.fm Draft Document for Review April 7, 2004 6:15 pm
82 IBM eServer zSeries 990 Technical Guide
Figure 3-6 Upgrade example with the STI Rebalance feature (FC 2400)
Now you can see that the required number of STI links is spread across all books MBAs,
including the two newly installed books 2 and 3, and redistributed across the existing I/O
cages. The result is a balanced STI system, as if a new build 2084-D32 server was initially
configured.
On the other hand, an upgrade including the STI Rebalance feature (FC 2400) is disruptive,
as STI cables must be reconnected to other STI locations, affecting the corresponding I/O
domains. After the Power-on Reset, SAPs are assigned to channel cards using the new STI
links configuration.
Adding a book via MES will result in STI plugging that is different from new build STI plugging
with the same number of books. FC 2400 can be ordered to replug the STIs as new builds.
The concurrent addition of a single book is supported, but be aware that regardless of how
the customer planned the previous configuration, the CHPID Mapping Tool (CMT) can be
used to evaluate the effects of FC2400 on the current configuration.
򐂰If you take the current IOCP statements and the current CFReport (provided by the IBM
Account Representative) and input these via the availability option in the CMT, it will be
Important: If the z990 STI Rebalance feature (FC 2400) is selected at server upgrade
configuration time, and effectively results in STI rebalancing, the server upgrade will be
disruptive.
The z990 STI Rebalance feature may also change the Physical Channel ID (PCHID)
number of ICB-4 links (see “Physical Channel IDs (PCHIDs)” on page86), requiring a
corresponding update on the server’s I/O definition via HCD/HCM.
2084-D32 CEC Cage
I/O Cage 1 I/O Cage 2
Book 0 Book 1
STIs
I/O Domains
STI Links I/O Cards
Book 2
Book 3
MBA
0MBA
1MBA
2MBA
0MBA
1MBA
2MBA
0MBA
1MBA
2
MBA
0MBA
1MBA
2