Chapter 3. I/O system structure 91
Draft Document for Review April 7, 2004 6:15 pm 6947ch03.fm
– Feature code 0218 is for the ISC Daughter card (ISC-D).
One ISC Mother card supports up to two ISC Daughter cards, and each ISC Daughter card con-
tains two ports. Port activation must be ordered using feature code 0219. RPQ 8P2197 is avail-
able to extend the distance of ISC-3 links to 20 km at 1Gb/sec. When RPQ 8P2197 is ordered,
both ports (links) in the card are activated.
10. The maximum number of ISC-3 ports in peer mode is 48, and the maximum number in compat-
ibility mode is 32.
11. There are two types of “virtual” links that can be defined and that require CHPID numbers, but
don’t have PCHID numbers:
– Internal Coupling (IC) links; each IC link pair requires two CHPID numbers.
– HiperSockets, also called Internal Queued Direct I/O (iQDIO). Up to 16 virtual LANs can be
defined, each one requiring a CHPID number.
12. Two ETR cards are automatically included in a server configuration if any coupling link I/O fea-
ture (ISC-3, ICB-2, ICB-3 or ICB-4) is selected.
13. The sum of PCIXCC and PCICA cards on a z990 server is limited to 8.
14. The PCIXCC and PCICA features do not require CHPIDs but have PCHIDs.
15. The maximum number of PCICA cards per I/O cage is 2.
At least one channel I/O feature (FICON Express or ESCON) or one Coupling Facility link I/O
feature (ISC-3, ICB-2, ICB-3 or ICB-4) must be present in a configuration.
The maximum number of configurable CHPIDs is 256 per Logical Channel Subsystem
(LCSS) and per operating system image.
Spanned and Shared channels
The Multiple Image Facility (MIF) allows channels to be shared among multiple logical
partitions in a server:
򐂰MIF shared channels can be shared by logical partitions within a Logical Channel
Subsystem (LCSS).
򐂰MIF spanned channels can be shared by logical partitions within and across LCSSs.
Table3-8 shows which channel types can be defined as MIF shared and/or MIF spanned
channels on a z990 server.
Table 3-8 Spanned and shared channels
Channel type CHPID definition MIF shared channel MIF spanned channel
ESCON external CNC, CTC yes no
CVC, CBY no no
FICON Express external FC, FCP yes yes
FCV yes no
OSA-Express external OSC, OSD, OSE yes yes
ICB-4 external CBP yes yes
ICB-3 external CBP yes yes
ICB-2 external CBS yes yes
CBR no no
ISC-3 external CFP yes yes
CFS yes yes
CFR no no