Setting Scsi Ids; Scsi Connector Pin-Number Assignments - IBM eServer 250 xSeries User Reference Manual

Setting SCSI IDs

Each SCSI device connected to a SCSI controller must have a unique SCSI ID. This ID
enables the SCSI controller to identify the device and ensure that different devices on
the same SCSI channel do not attempt to transfer data simultaneously. SCSI devices
that are connected to different SCSI channels can have duplicate SCSI IDs. SCSI IDs 6
and 7 are reserved for the SCSI controller on either SCSI channel A or B. The following
table lists the SCSI IDs for devices that are connected to one channel. In Table 10, the
hot-swap hard disk drive bays are in the standard (vertical) configuration.
Standard (SCSI
channel A)
Drive bay 1:
SCSI ID 0
Drive bay 2:
SCSI ID 1
Drive bay 3:
SCSI ID 2
Drive bay 4:
SCSI ID 3
Drive bay 5:
SCSI ID 4
Backplane: SCSI
ID 8
The hot-swap-drive backplane controls the SCSI IDs for the internal hot-swap drive
bays. However, when you attach a SCSI device to the external SCSI connector, you
must set a unique ID for the device. Refer to the information that comes with the
device for instructions to set its SCSI ID.

SCSI connector pin-number assignments

The following table shows the pin-number assignments for the 68-pin SCSI
connectors.
34
68
Optional (SCSI
channel B)
Drive bay 1:
SCSI ID 11
Drive bay 2:
SCSI ID 12
Drive bay 3:
SCSI ID 13
Drive bay 4:
SCSI ID 14
Drive bay 5:
SCSI ID 15
Backplane: SCSI
ID 9
Table 10. SCSI IDs for hot-swap hard disk drives
and backplanes (standard configuration).
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Chapter 5. Installing options
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