Appendix D Rules for System Configuration

Some of the following rules are suggestions for optimizing your system. Other rules are strictly required and are marked with the notation Requirement or Maximum.

Card Cage

As a general rule, all board slots in the card cage are interchangeable. However, the requirements and limitations in the following sections apply when you install boards.

CPU/Memory+ Boards

1. Install CPU/Memory+ boards at the front of the system, starting with the top slot (slot 0). If you reserve the rear slots for I/O+ boards, I/O cable attachments will be made easier.

2. After the front slots are filled, you may add CPU/Memory+ boards at the rear of the system, below the I/O+ boards.

I/O+ Boards

1. Requirement-An I/O+ board must always be in slot 1. This is the only slot that allows access internally to the internal SCSI devices (tape and CD-ROM drives.)

2. Install I/O+ boards at the rear of the system to facilitate I/O cable attachments.

3. If you require additional slots, you may use those at the front of the card cage, preferably below the CPU/Memory+ boards.

4. Maximum-Up to four graphics (UPA) cards are supported in a system.

5. Requirement-The I/O+ board in slot 1 of any Enterprise server must be terminated because it connects to the media tray.

6. An I/O+ board in a slot other than slot 1 does not require termination if no devices connect to the SCSI bus on that board.

Disk Board

1. Maximum-The Enterprise 6500 system supports up to two Disk boards. (Disk boards are supported only in slots 14 and 15. Slot 15 must be used when installing only one Disk board.)

2. Maximum-The Enterprise 5500 and 4500 systems support up to four disk boards.

3. The disk board has a capacity of two disk drives. In addition to the three status LEDs found on other types of boards, the disk board has two LEDs to show the status of the individual disk drives. LEDs 1 and 2 represent drives 0 and 1, respectively.

Power Supplies and Fan Cooling

1. Requirement-The fans in the power/cooling modules (PCMs) provide cooling air only for the two adjacent board slots. Do not install a board in a slot that is not cooled by a PCM.

2. Requirement-You must fill all empty slots (board slots and power supply slots) to avoid loss of cooling air to the active boards. For further information on this subject, see "Filler Panels and Load Boards".

3. Under some circumstances, you may remove a power/cooling module from an active system for a short time. However, if the boards in the adjacent slots create large quantities of heat, it is safer to halt and power off the system first.

Filler Panels and Load Boards

1. Requirement-All empty board slots must be filled with filler panels or load boards.

2. Requirement-For Enterprise 6500 systems, use load boards. A load board (part number 501-3142) is identified by the presence of connector sockets and passive circuitry, which reduces electrical noise at the center plane. Do not substitute filler panels, which do not have load circuits.

3. Requirement-For Enterprise 5500 and 4500 systems, use filler panels (part number 540-2592).

4. Requirement-Filler panels are required for all unused PCM bays.

SBus Modules

1. Install double-wide SBus cards only on the SBus+ I/O board, at SBus slots 1 and 2. The location of SBus slot 0 prevents its use with double-wide cards.

2. Double-wide SBus cards cannot be used with the Graphics+ I/O board. The middle card connector does not fit SBus cards.

CPU Modules

1. Each CPU/Memory+ board has two sets of CPU connectors, marked "PROC 0" and "PROC 1".

2. Do not mix CPU speeds.

3. Requirement-To run 250 MHz CPU modules: (1) use only clock+ board part number 501-4286 and (2) do not mix 250 MHz CPU modules with CPU modules of a different speed.

4. The order in which CPU slots are filled is not critical. However, to optimize heat dissipation in the system:

• Fill all "PROC 0" locations on all CPU/Memory+ boards before filling any "PROC 1" locations. To receive the maximum quantity of diagnostic information, fill "PROC 0" on board 0.

• After all "PROC 0" locations are filled, you can begin filling the "PROC 1" locations, again starting from the lowest slot number to the highest.

Table D-1 shows slot locations for an example of five CPUs on three CPU/Memory+ boards.

Table D-1 Example of CPU Placement

Slot Number	"PROC 0"	"PROC 1"
0	in	in
2	in	in
4	in	--

Memory Modules

1. The SIMMs are 168-pin, JEDEC-standard devices. Do not use other types of memory modules.

2. Requirement-All SIMMs in a bank (eight SIMMs) must have the same capacity. Do not mix 8, 32, or 128 Mbyte SIMMs in the same bank.

3. All SIMMs in a bank should have the same speed rating. If SIMMs of different speeds are mixed in a bank, the bank will function, but at the lowest speed.

Power Supplies

Requirement-Only the peripheral power supply provides precharge current to the system. The peripheral power supply must be fully functional if you replace a hot-pluggable board or PCM. If the peripheral power supply cannot supply precharge current, the hot-pluggable unit will be damaged.

Disk Drives

1. The disk array containing the boot disk should be connected to the I/O+ board in card cage slot 1.

2. Additional drive arrays may be attached to I/O+ boards in any other card cage slot.

3. In the Enterprise 6500 and 5500 systems, optional disk arrays can be mounted under the card cage. The maximum number of arrays supported by Sun varies with the server type and the physical size of the trays.

CD-ROM/Tape Drive Media Tray

1. For the 8-slot Enterprise 4500 system, the optional CD-ROM and tape drives are mounted horizontally in a media tray that is attached to the card cage.

2. For the 16-slot Enterprise 6500 and 8-slot Enterprise 5500 cabinets, the optional CD-ROM and tape drives are mounted vertically in a media tray that is attached to the rack. Note that the 8-slot card cage is the same unit as is used in the 8-slot stand-alone unit, but with filler panels in the unused card cage media tray and key switch compartments.

3. The Enterprise 6500 and 5500 systems have space above the card cage for an optional multi-tape backup tray or tape library unit.

Connecting Cables

SCSI

1. Maximum-The maximum length for a chain of non-differential SCSI cables is 6.0 meters (20 feet).

2. Maximum-The maximum length for a chain of differential SCSI cables is 25 meters (82 feet).

Ethernet

1. The main Ethernet should be connected to the I/O+ board in slot 1.

2. Additional Ethernet connections may be made to I/O+ boards in any other card cage slot.

Video Interface

1. A system that is operated with a monitor may use a graphics adapter mounted on either a Graphics+ I/O board or an SBus+ I/O board.

2. Up to four Graphics+ I/O boards are supported in a system.