Dell Inspiron 2100, Service Manual

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1-8 Dell PowerEdge 2100/180 and 2100/200 Systems Service Manual
SCSI ID Numbers
Each device attached to the SCSI host adapter must have a unique SCSI ID
number from 0 to 15. See Chapter 9, “Installing Drives in the Internal Bays” in
the User’s Guide for additional SCSI addressing information.
NOTE: Any narrow SCSI devices installed in the external drive bays will
require SCSI ID numbers less than 7.
When SCSI devices are shipped from Dell, the default SCSI ID numbers are
assigned as follows:
•
The computer’s built-in SCSI controller is configured through the BIOS as
SCSI ID 7 (the default ID number for a host adapter) if the system includes
a CD-ROM or tape drive.
NOTE: If only wide SCSI hard-disk drives are connected to the built-in SCSI
controller (no CD-ROM or tape drives), it may be configured as SCSI ID
15.
•
A SCSI CD-ROM drive (installed in an externally-accessible drive bay) is
configured as SCSI ID 5.
•
A SCSI tape drive (if installed) is configured as SCSI ID 6.
•
The drive you intend to use as your boot device should be configured as SCSI
ID 0. You can configure any additional hard-disk drives to any of the still-
available SCSI ID numbers.
•
If Dell installs additional SCSI hard-disk drives in the system, they will be
configured as SCSI ID 1 and SCSI ID 2.
NOTE: There is no requirement that SCSI ID numbers be assigned sequentially or
that devices be attached to the cable in order by ID number.
Device Termination
Before installing SCSI devices, you must configure the termination on the
device(s) and for the built-in SCSI controller according to the guidelines listed
in the following text.
SCSI logic requires that termination be enabled for the two devices at opposite
ends of the SCSI chain and disabled for all devices in between. To that end,
regardless of whether you are installing internal or external devices, use the fol-
lowing guidelines:
•
The built-in SCSI controller has active termination — no action is required.
•
When the SCSI hard-disk drives are installed by Dell, termination is set to
enabled on the SCSI hard-disk drive installed in the left bay of the SCSI
hard-disk drive cage. Termination should be disabled on any other drives
installed in the SCSI hard-disk drive cage. Figure 1-5 shows some examples
of SCSI termination jumpers.