IBM 8671 - Eserver xSeries 235, Maintenance And Troubleshooting Manual

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Domain name validation to negotiate compatible data-transfer speeds with each
device
v Parity checking to ensure data reliability
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An active terminator for SCSI bus termination
The server comes with one SCSI cable that is connected from the internal SCSI
channel A connector to the standard hot-swap-drive backplane. You can attach
additional internal SCSI devices to the other internal SCSI channel B connector, or
you can use channel B for external SCSI devices. To use channel B for external
SCSI devices, remove the external SCSI knockout from the rear of the server (see
“Cabling the server” on page 106 for external SCSI knockout location) and secure
the free end of an optional channel B cable in the new opening.
If you want to attach external SCSI devices to the server without using the internal
SCSI channel B, you must install an optional SCSI adapter.
Notes:
1. External SCSI devices connected to internal SCSI channel B will operate
asynchronously.
2. If you install a PCI RAID adapter to configure and manage the internal hot-swap
drives, you must move the SCSI cable from the system-board 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 66 for additional information.
Note: If you install a PCI RAID adapter to configure and manage the internal
hot-swap drives, you must move the SCSI cable from the system-board
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 66 for additional information.
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 8 on page 112 and Table 9 on page 112 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” on page 70 for instructions for installing the 3-Pack
option, and “Installing internal drives” on page 74 for instructions about installing
hard disk drives.
Chapter 4. Customer replaceable units
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