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Parts Information |
Document ID: DDSE-42DV7Q |
Netfinity 3000 - SCSI Drives
Applicable to: World-Wide
SCSI Drives: Some drives have a special design called small computer system interface (SCSI). This design allows you to attach multiple drives to a single connector.
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The 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 the server supports, go to http://www.pc.ibm.com/us/netfinity/ on the World Wide Web.
SCSI Physical Unit Numbers: 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 of methods to set the SCSI ID, such as jumpers, thumbwheels, or switches.
The SCSI device ID is also known as the SCSI address or physical unit number (PUN).
The UltraSCSI adapter in the server supports SCSI IDs 0 to 15; ID 7 is reserved for the adapter. The default startup (boot) SCSI ID is 0 for an internal SCSI hard disk drive in Channel A. Use SCSISelect to view the SCSI IDs of SCSI devices in the server. (See "SCSISelect Utility Program" for more information.)
If you install wide (16-bit) SCSI devices, you can set the IDs to any number between 0 and 6, or between 8 and 15. If you install narrow (8-bit) SCSI devices, you can set the IDs to any number between 0 and 6.
SCSI Logical Unit Number: Each physical device has a physical unit number (PUN) and a logical unit number (LUN). If a physical device supports no logical
devices, its LUN is 0. Most SCSI devices support only LUN 0. Certain types of physical SCSI devices ( bridge controllers) can support more than one logical device.
For example, a printer controller might support up to eight printers. The printer controller is a physical device, and each printer is a logical device. If the printer controller is
assigned to ID 2, the ID of the first printer appears in the SCSI device configuration as PUN 2, LUN 0. The IDs of the other printers are PUN 2, LUN 1; PUN 2, LUN 2; on up
to PUN 2, LUN 7.
Termination Requirements: The Netfinity 3000 server comes with an UltraSCSI adapter. The SCSI bus must be terminated at both ends only. The UltraSCSI adapter provides termination for one end of the SCSI bus (cable) in the server. The SCSI cable in the server comes with a terminator that provides termination for the other end of the SCSI bus. Therefore, any internal SCSI devices that are installed must have their termination set to Disabled.
- When you install devices in bays 2, 3, 5, and 6, you must disable the termination for the devices before you install them.
- If you connected external SCSI devices to the server, set the termination for the last device on the external cable to Enabled. See the device documentation for instructions.
If you plan to install both 16-bit (wide) and 8-bit (narrow) SCSI devices:
1. Attach the 16-bit devices at the beginning of the SCSI chain.
2. Attach the 8-bit devices at the end of the SCSI chain.
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Before you begin, be sure you have: |
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Document Category |
CD-ROM Drives, Hard Drives, Tape Drives | |
Date Created |
20-11-98 | |
Last Updated |
23-11-98 | |
Revision Date |
20-11-99 | |
Brand |
IBM PC Server | |
Product Family |
Netfinity 3000 | |
Machine Type |
8476 | |
Model |
ALL | |
TypeModel |
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