The default SCSI ID numbers for devices in the media tray are:
Table C-1 Media Tray Default SCSI ID Numbers
Device |
ID |
---|---|
CD-ROM |
6 |
Tape drive |
5 |
The default SCSI ID numbers for disk drives on the Disk boards are listed by server type in TABLE C-2.
Table C-2 Disk Board Default SCSI Disk Drive ID Numbers
|
Board Slot |
Disk 0,1 |
Board Slot |
Disk 0,1 |
---|---|---|---|---|
Enterprise 4500 or 5500 |
||||
|
0 |
4, 5 |
1 |
6, 7 |
|
2 |
0, 1 |
3 |
10, 11 |
|
4 |
2, 3 |
5 |
12, 13 |
|
6 |
8, 9 |
7 |
14, 15 |
Enterprise 6500 only |
||||
|
14* |
0, 1 |
15* |
10, 11 |
*Enterprise 6500 systems: Disk boards can only be installed in slots 14 and 15. |
You can override the default IDs by jumpers on each disk board. Each disk has an ID_ENABLE jumper and four ID jumpers. If the ID_ENABLE jumper is not installed, the disk drive uses the default SCSI ID. If the ID_ENABLE jumper is installed, the disk drive uses the ID specified by the four ID jumpers located on the disk board (an installed jumper indicates a logical 1).
For Enterprise 4500 and 5500 servers, default disk drive ID numbers are chosen so that IDs 4, 5, 6, and 7 are unlikely to be assigned to disk drives. These IDs are in slots 0 and 1, which are normally taken by a CPU/Memory+ board (slot 0) and an I/O board (slot 1).
The maximum combined length for a string of SCSI cables is 6 meters for non-differential cables. For differential SCSI cables, the maximum is 25 meters. To calculate the total length of a SCSI string, include external cables, internal cables, and printed traces. Table C-3 lists measurements for Enterprise servers.
Table C-3 Internal SCSI Lengths (Approximate)
Location |
Internal Length |
Comments |
---|---|---|
Enterprise 6500 slot 1 |
3.7 meters |
Includes I/O+ board traces and cables to media tray |
Enterprise 5500 slot 1 |
3.7 meters |
Includes I/O+ board traces and cables to media tray |
Enterprise 4500 slot 1 |
1.4 meters |
Includes I/O+ board traces and cables to media tray |
SBus+ I/O board |
0.43 meter |
Includes board traces only |
Graphics+ I/O board |
0.43 meter |
Includes board traces only |
Disk board |
0.64 meter |
Includes board traces only |
The I/O+ board in slot 1 of any Enterprise server must be terminated. This slot connects to the media tray through cables and a connector on the centerplane.
I/O+ boards in other slots do not require termination if no devices connect to the SCSI bus on those boards.