IBM 8681 Hardware Maintenance Manual - Page 120

Empty hot-swap bays and trays that contain slim-high drives must contain a filler bezel. The diskette drive uses 2 MB diskettes. For optimum use, format 2 MB diskettes to 1.44 MB. Hard disk drives: The server comes with a Wide Ultra-2 SCSI (LVD) controller on the I/O function card. Notes 1. LVD = low-voltage differential 2. If you plan to install both internal and external SCSI devices, you must follow the instructions in "External options" on page 70, in addition to the instructions in this section. A 16-bit (wide) SCSI cable connects the hot-swap backplane to one channel of the integrated SCSI controller on the I/O function card. SCSI IDs: Each SCSI device that is connected to an individual integrated SCSI controller needs a unique identification (ID) so that the controller can identify the devices and ensure that different devices do not attempt to transfer data at the same time. (The integrated SCSI controllers operate independently.) If you need to set IDs for SCSI devices, refer to the instructions that come with those devices. The server automatically sets SCSI IDs for hot-swap hard disk drives. The server uses the hard disk drive SCSI IDs to send status information to the indicator lights located on each hot-swap drive. Note Do not set the SCSI ID jumpers on hard disk drives. The SCSI backplane in the server supports up to two hot-swap drives. Table 12 shows the default SCSI IDs that the backplane assigns for hot-swap hard disk drives. Table 12. Automatically assigned SCSI IDs Bay 1 2 ID 0 1 Note: The default SCSI ID for the SCSI backplane is 15. The default SCSI ID for each SCSI controller is 7. A simplified layout of the SCSI backplane is shown in "SCSI backplane component locations" on page 160. The processing sequence for SCSI devices is set through the SCSISelect Utility program. The default sequence proceeds from the lowest SCSI ID to the highest (0 to 6, then 8 to 14). The default SCSI ID for each SCSI 112 Netfinity Server HMM