Feature Plugging Rules

---7 meters (20 feet) 54G3409 13 meters (40 feet) 54G3410 22 meters (70 feet) 54G3411 31 meters (100 feet) 54G3412 46 meters (150 feet) 54G3413 61 meters (200 feet) 54G3414 Custom Length 54G3415

2.4 Feature Plugging Rules

OSA-Express GbE features plug into specific I/O slots of an I/O cage.

OSA-Express GbE cards can be hot plugged, and the Self-Timed

Interconnect (STI) bus can be hot plugged into OSA-Express GbE cards.

Unlike other I/O cards, OSA-Express GbE cards cannot be concurrently uninstalled from a configuration.

Note: From a Support Element point of view, you can remove an

OSA-Express GbE card in a G5 or G6 Server. However, this is only exploited to move an OSA-Express GbE card for an MES.

Even though OSA-Express GbE can technically plug into any I/O slot, the OSA-Express GbE features have some very specific rules for sequence and location to facilitate optimum CHPID utilization and offer stability for

manufacturing and service.

A total of 24 OSA-Express GbE and FICON cards can be installed on a G5 or G6 Server. A maximum of 12 of these cards can be OSA-Express GbE features. This means FICON features and OSA-Express GbE features share the available I/O slots.

2.4.1 I/O Cage Order

The I/O cage plugging order will be 3, 1, 2. That is, in a configuration with three I/O cages, OSA-Express GbE and/or FICON cards will start plugging into I/O cage 3 (top of the Z frame). In a configuration with one or two I/O cages, OSA-Express GbE and/or FICON cards start plugging into I/O cage 1 (bottom of the A frame).

Planning Information 19 A configuration of one to six OSA-Express GbE and or FICON cards can be accommodated in a single I/O cage. More than six OSA-Express GbE and/or FICON cards (up to 12) will require a second I/O cage, and 13 to 18

OSA-Express GbE and/or FICON cards will require three I/O cages. An I/O cage is populated (six cards) with OSA-Express GbE and/or FICON cards before plugging starts in the next I/O cage. When a machine requires more than 18 OSA-Express GbE and/or FICON cards, plugging resumes with I/O cage 3, and each I/O cage receives an additional two OSA-Express GbE and or FICON cards for the total of 24.

If a third I/O cage is (MES) added to a configuration containing OSA-Express GbE and/or FICON cards, some OSA-Express GbE and/or FICON cards will have to move to the new (third) I/O cage. If there are OSA-Express GbE and/or FICON cards in I/O cage 2, those move to I/O cage 3. If there are none in I/O cage 2, but some in I/O cage 1, the OSA-Express GbE and/or FICON cards in I/O cage 1 move to I/O cage 3. These are only physical moves of the OSA-Express GbE and/or FICON cards and cables. Customer CHPID numbers will not be impacted because the same STIs plug into the same OSA-Express GbE and/or FICON cards.

Note:If a second I/O cage is added to a configuration with only one I/O cage, there is no movement of OSA-Express GbE and or FICON cards required.

Note:If the MES adds OSA-Express GbE and/or FICON cards to the third I/O cage, no OSA-Express GbE and/or FICON cards are moved.

2.4.2 I/O Cage Slots Used

Regardless of how the I/O cage is being populated, the slot sequence used for OSA-Express GbE and/or FICON cards remains the same: 31, 06, 32, 07, 33, 34. This sequence is repeated for each I/O cage (3,1,2) giving a total of 18 OSA-Express GbE and/or FICON cards.

These represent domain 2 (6-slot domain) of the I/O cage. When additional OSA-Express GbE and/or FICON cards are required, the sequence resumes with I/O cage 3 and slots 08 and 25 being used. These same slots are subsequently used in I/O cages 1 and 2 to provide the 24 maximum.

When an MES adds OSA-Express GbE and/or FICON cards to a

configuration, existing adapters may have to be relocated. In the case of I/O cards, this can be done with disruption only to the channels being moved.

That means the customer will have to configure the channels offline, and then after the move, ensure that the new CHPID numbers are defined in his configuration (via dynamic I/O change or defining them ahead of time) and

configure the new channel number online. However, if an ISC adapter is being moved, the system has to be powered off because ISC adapters cannot be hot-plugged.

2.4.3 STI and CHPID Assignments

STIs are plugged into either FIB cards for normal I/O or into direct attachments. Direct attachments can be OSA-Express GbE, FICON, or Integrated Cluster Bus (ICB). STIs 00-08 are normally used for FIBs. Direct attachments start with STI 09 and proceed up the STI numbers. In smaller systems and those with a high number of direct attachments, after the highest STI is plugged, STI-8 is then used for direct attach, then STI-07, 06, 05, and so forth.

There is an order in which STIs get allocated for direct attachments: first is ICB, followed by FICON, and then OSA-Express GbE. This order cannot be relied upon because features can be MES added at any time.

STIs will always be allocated in pairs for OSA-Express GbE and or FICON attachments. That is, when an STI is used to attach an OSA-Express GbE or FICON card, the next sequential STI is reserved for the next OSA-Express GbE or FICON card and cannot be used for any other direct attachment (for instance ICB). This ensures that OSA-Express GbE or FICON cards in a connected chain will have access to different MBAs and, in the case of Gemi models, different MBA clusters.

STIs used for direct attachments may not be intermixed with STIs used for FIBs. For example, if STI-7 is used for an FIB, STIs 0-6 may not be used for direct (ICB or OSA-Express GbE or FICON) attachments.

The assignment of CHPID numbers depends on what the STI is used for (ICB or OSA-Express GbE, FICON):

• STIs for direct attachments are always assigned CHPID numbers from the upper end of the CHPID range.

• The first ICB is assigned the next available modulo-4 CHPID number (for instance FC, F8, F4, and so on). The next 3 STIs with ICBs receive consecutive CHPID numbers (for example FD, FE, FF). The 5th, 9th, 13th, and so forth, STIs with ICBs repeat the process.

• The first OSA-Express GbE or FICON is assigned the next available modulo-4 CHPID number (for example FC, F8, F4, and so forth). The second STI with an OSA-Express GbE or FICON will receive the next available modulo-4 CHPID number (for example F8, F4, and so forth). Any OSA-Express GbEs or FICONs chained to these STIs will get consecutive CHPID numbers from the first or second OSA-Express GbE or FICON. For

Planning Information 21 example, if STI-09 and 10 were used for OSA-Express GbE or FICON, the following assignments would be made: 09=FC, 10=F8. Any OSA-Express GbEs or FICONs chained to STI-09 would get CHPID numbers FD, FE, FF, and any OSA-Express GbEs or FICONs chained to STI-10 would get CHPID numbers F9, FA, FB.

3. STIs for OSA-Express GbEs and or FICONs are always allocated in pairs.

If only one STI was used for OSA-Express GbE or FICON, the next available STI would be reserved for future OSA-Express GbE or FICON use (the reserved STI could be used for an FIB as long as no ICBs follow it). If an ICB follows a reserved STI, the CHPID numbers assigned for that STI must also be reserved.

Whenever an STI is used for direct attachment, I/O cards sharing the same CHPID numbers or I/O cards assigned CHPID numbers between the last used direct-attached STI and the new STI, must be moved or removed from the configuration. For example:

• STI-9 through 12 are used for ICB. The channel card for FC-FF must be moved or removed as soon as STI-9 is used.

• Then STI-13 is used for OSA-Express GbE or FICON. The channel card for F8-FB must be moved or removed as soon as STI-13 is used.

• Then another ICB is added in STI-15 (STI-14 is left reserved for another OSA-Express GbE or FICON). Channel cards for F4-F7 (for the reserved OSA-Express GbE or FICON STI) and F0-F3 (for the new ICB) must be moved or removed as soon as STI-15 is used.

2.4.4 Chaining

Full chaining is available for OSA-Express and FICON. It provides two main functions. First, because only one STI is used for four OSA-Express GbE or FICON cards, the number of STIs required is reduced. Second, two chains are "cross-chained", thus providing a backup STI for the OSA-Express GbE and FICON cards in case of an STI or OSA-Express GbE or FICON failure;

this is called Alternate Path support.

In the event of a card failure, the alternate path feature is enabled, allowing access to the cards that may be blocked by the failing card. This mode is enabled either automatically or manually, depending on the card failure. A repair action should be scheduled as soon as possible, since card performance may be impacted in card chains greater than four in addition, there is no alternative path should a second card fail.