IBM Netfinity 3000, User Handbook Manual, Page: 144 / 370

Installing or removing internal drives
SCSI drives (if your server model comes with a SCSI
adapter)
Note: If your server model comes with a SCSI adapter, the adapter
is an IBM UltraSCSI adapter. The information in this SCSI
section applies to an UltraSCSI adapter. If your server model
does not come with a SCSI adapter and you or your dealer
have installed a SCSI adapter, consult the documentation that
comes with that adapter for information on SCSI devices.
Then, proceed to “Preinstallation steps (all bays)” on
page 112.
Some drives have a special design called small computer system
interface (SCSI). This design allows you to attach multiple drives to
a single connector.
Note: Any information about SCSI drives also applies to other SCSI
devices, such as scanners and printers.
Your Netfinity 3000 server supports drives that comply with
American National Standards Institute (ANSI) SCSI Standards
X3.131-1986 (SCSI), X3.131-1994, (SCSI-2), X3.277-1996 (SCSI-3
Fast-20 parallel interface), and X3.253-1995 (SCSI-3 parallel interface).
For a complete list of the SCSI devices that your server supports, go
to http://www.ibm.com/netfinity/ on the World Wide Web.
SCSI physical unit numbers (PUNs)
When more than one physical device is connected to the same
UltraSCSI adapter, the devices compete for support from the
UltraSCSI adapter. Because the UltraSCSI adapter communicates
with only one device at a time, the priority of a device is based on
its SCSI identification (ID). The highest priority IDs are 7 to 0; the
lowest priority IDs are 15 to 8.
If you install additional SCSI devices, you must set a unique ID for
each SCSI device that you connect to the integrated SCSI-2
connector. This unique ID enables the UltraSCSI adapter to identify
the devices and to prevent two devices from sending or receiving
data on the SCSI bus at the same time. SCSI devices use a variety
110
Netfinity 3000 User's Handbook