Hard Drive Installation Guide
SCSI Devices
This section contains information relating to SCSI device guidelines and installation.
Guidelines for Using SCSI Devices
When installing and operating SCSI devices, you must follow these guidelines:
■A single Ultra SCSI controller supports up to seven SCSI devices per channel.
■Each Wide-Ultra SCSI, Ultra-Wide SCSI, Wide Ultra2 SCSI, Ultra 320 SCSI, or Ultra 160 SCSI controller supports up to 15 SCSI devices per channel.
■If using multiple SCSI devices, Compaq recommends that the devices be split between Channel A and Channel B, if available, for optimum performance.
■SCSI cable recommendation:
❏53 inches maximum length twisted-pair, LVD cable with built-in terminator, maximum of 5 drives with a minimum driving spacing of 5.25 inches.
■The SCSI controller requires a unique SCSI ID (0-7 or 8-15) for each SCSI device installed. The controller identifies a SCSI device by its SCSI ID number rather than by its location. Moving a SCSI device from one position to another on the SCSI chain does not affect communication between the controller and the device. The reserved and available SCSI ID numbers for SCSI devices are:
❏0—reserved for the primary hard drive
❏7—reserved for the controller
❏1 through 6 and 8 through 15—available for all other SCSI devices
Hardware Reference Guide | B-3 |