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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.

Note Any information about SCSI drives also applies to other SCSI devices, such as scanners and printers.

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.

Note The beginning of the SCSI chain is the end closest to the SCSI adapter or the system board.

This enables the UltraSCSI adapter to recognize all of the devices in the SCSI chain, and thus ensures proper server
operation.

Refer to the instructions that come with the SCSI device for more information about termination.

Preinstallation Steps (All Bays)

Before you begin, be sure you have: - Read Safety Information on page 206. - Read the documentation that comes with the option. - Read Termination Requirements. - Verified that you have all cables, drive trays, and any other equipment specified in the documentation that comes with the internal drive.

Before you can install drives in the Netfinity 3000 server, you might need to perform certain preinstallation activities. Some of the steps are required only during the initial installation of an option.
1. Remove the server side cover (see "Disconnecting Cables and Removing the Side Cover").
2. Choose the bay in which you want to install the drive. (Refer to Table 4 for the drive types and sizes available for each bay.)
3. Access the appropriate drive bays.

Notes 1. In all models, drive bays 1 and 4 come with drives preinstalled. 2. In some models, drive bay 6 comes with a drive preinstalled. 3. Drive bays 2 and 3 have a bay panel and static shield installed. 4. If you remove a drive that has removable media and you do not intend to install a new drive immediately, reinstall the static shield and bay panel for that bay.

To access drive bays 1 through 4, go to "Working with Drives in Bays 1 through 4".

To access drive bays 5 and 6, go to "Working with Drives in Bays 5 and 6".

4. Touch the static-protective bag containing the drive to any unpainted metal surface on the server; then, remove the drive from the bag.
5. Check the instructions that come with the drive, or contact your IBM reseller or IBM marketing representative to see if you need to set any switches or jumpers on the drive, or if you need to attach a tray to the drive.

	Search Keywords
	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
	Retain Tip (if applicable)
	Reverse Doclinks and Admin Purposes