Dell PowerEdge 1500SC - Manual (Page 46)

Interface Cables
Most interface connectors are keyed for correct insertion; that is, a notch or a raised tab on one connector matches a tab or a notch on the other connector.
Keying ensures that the pin-1 wire in the cable goes to the pin-1 ends of the connectors on both ends.
When you disconnect an interface cable, take care to grasp the cable connector, rather than the cable itself, to avoid stress on the cable.
DC Power Cables
Each drive in the external drive bays must connect to a 4-wire DC power cable from the system power supply. The connectors on these cables are labeled
"P3," "P4," "P5," and "P6." Connectors P3, P4, and P5 are used for 5.25-inch devices; connector P6 is used for the 3.5-inch diskette drive.
SCSI Configuration Information
Although SCSI devices are installed essentially the same way as other devices, their configuration requirements are different. To configure SCSI devices
installed in the external bays, follow the guidelines in the following subsections.
SCSI ID Numbers
Each device attached to the SCSI host adapter must have a unique SCSI ID number from 0 to 7.
When SCSI devices are shipped, the default SCSI ID numbers are assigned as follows:
l The integrated SCSI host adapter is configured through the BIOS as SCSI ID 7.
l A SCSI tape drive is configured as SCSI ID 6 (the default ID number for a tape drive).
Device Termination
SCSI logic requires that the two devices at opposite ends of the SCSI chain be terminated and that all devices in between be unterminated. The SCSI cable
included in your system has an active terminator installed at the end of the cable. Disable the termination on all SCSI devices you attach to this cable.
Installing SCSI Hard Drives
This subsection describes how to install and configure SCSI hard drives in the system's internal hard drive bays, and how to upgrade the system by installing a
host adapter expansion card.
The internal hard drive bays provide space for up to six 1-inch hard drives. These drives connect to a SCSI backplane board. A SCSI cable connects the SCSI
backplane board to the SCSI host adapter connector on the system board or to an optional SCSI host adapter card.
Before You Begin
Before attempting to remove or install a drive while the system is running, see the documentation for the host adapter card to ensure that the card is
configured correctly to support hot-pluggable drive removal and insertion.
SCSI hard drives are supplied in special drive carriers that fit in the hard drive bays.
See the following guidelines when you configure the SCSI drive:
l Disable termination on the drive. The SCSI backplane board provides termination for the SCSI bus.
l Set the SCSI ID on all drives to 0. All SCSI ID numbers for the drives are set by the SCSI backplane board.
l Configure the drive so that the drive motor waits for a Start Unit command from the SCSI host adapter before spinning.
When you format a high-capacity SCSI hard drive, allow enough time for the formatting to be completed. Long format times for these drives are normal. A 9 GB
hard drive, for example, can take up to 2.5 hours to format.
Installing a SCSI Hard Drive
1. If the system does not have a RAID controller installed, shut down the system.
2. Remove the front bezel (see " Removing the Front Bezel " in "Troubleshooting Your System").
3. Open the hard drive carrier handle (see Figure 7 -1 ).
NOTE: There is no requirement that SCSI ID numbers be assigned sequentially or that devices be attached to the cable in order by ID number.
NOTE: We recommend that you use only drives that has been tested and approved for use with the SCSI backplane board.
NOTICE: Do not turn off or reboot your system while the drive is being formatted. Doing so can cause a drive failure.
NOTICE: Hot-plug drive installation is not supported for systems without a host adapter expansion card.