Scsi Cabling Requirements; Scsi Ids - IBM eServer xSeries 235 Type 8671 Option Installation Manual

SCSI cabling requirements

For information about the maximum length of SCSI cable, see the American
National Standards Institute (ANSI) SCSI standards on the ANSI Web site at
http://www.ansi.org/ on the World Wide Web. Adhering to these standards will help
to ensure that your server operates properly.

SCSI IDs

Each SCSI device that is 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. Table 3 and Table 4 list the SCSI IDs for the hard disk
drives and backplanes that are connected to one channel. In the typical
configuration, the standard hard disk drives and backplane are connected to
channel A, and the optional 3-Pack hard disk drives and backplane are connected
to channel B. See "Working with the 3-Pack Ultra320 Hot-Swap Expansion option"
drives" on page 36 for instructions about installing hard disk drives.
The hot-swap-drive backplane controls the SCSI IDs for the internal hot-swap drive
bays. However, when you attach an external SCSI device to an optional SCSI
adapter, you must set a unique ID for the device. See the information that comes
with the device for instructions to set its SCSI ID.
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IBM xSeries 235 Type 8671: Option Installation Guide
SCSI connector to an internal channel connector on the RAID adapter
(except for the ServeRAID-5i controller, which uses the system-board
integrated SCSI controller with RAID capabilities). See "Cabling example for
a ServeRAID controller" on page 28 for additional information.
on page 32 for instructions for installing the 3-Pack option, and "Installing internal
Table 3. SCSI IDs for standard hot-swap hard disk drives and backplane
Device
Drive bay 5
Drive bay 4
Drive bay 3
Drive bay 2
Drive bay 1
Drive bay 0
Backplane
Table 4. SCSI IDs for optional 3-Pack hot-swap hard disk drives and backplane
Device
Drive bay 14
Drive bay 13
Drive bay 12
Backplane
SCSI ID
5
4
3
2
1
0
8
SCSI ID
14
13
12
9