Configuring HP-UX For Peripherals

Chapter 5 141
Configuring Disk Drives, Disk Arrays, and CD-ROM Drives
Selecting Device Drivers for a Disk Device and Interface
Selecting Device Drivers for a Disk Device
and Interface
The following sections (covering SCSI interfaces and floppy disk drives)
identify the device drivers that must be present in the kernel for HP-UX
to communicate with your disk device. Choose the device drivers based
on the interface to which you are configuring the disk device.
If you are configuring a custom-written device driver on a Series 700,
consult the Driver Development Guide for guidelines.
Once you have identified your device drivers, proceed to “Configuring
HP-UX for a New Disk Device”.
SCSI Disk Configuration Guidelines
The SCSI address of a device dictates the device's priority when
arbitrating for the SCSI bus. Use SCSI address 7 for the highest priority
device (usually the host), followed by subsequent addresses in
descending order: 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8.
Each fast/wide/differential SCSI-II card can support up to 15
peripherals, including up to 7 disk arrays. Due to limitations in SCSI-II,
disk arrays can be connected to addresses 0 through 7 only; do not
connect disk arrays to addresses 8 through 15.
HP-UX recommends UPS for power fail protection of
fast/wide/differential disk arrays.
Do not exceed 6 meters maximum cabling for single-ended SCSI and 25
meters maximum for fast/wide/differential SCSI configurations.
Make sure that every SCSI bus is properly terminated.
Table 5-1, “SCSI-II Disk Configuration Requirements,” lists the HP disk
and CD-ROM devices configurable through the SCSI interface on Series
700 and 800 systems.
Note, the c#t#d#[s#] syntax used in default device special files derives
from ioscan output: c# is the card instance for the ext_bus class of
interface card to which the device is attached, t# is the target (SCSI
address) of the disk device on the interface, d# is the device unit number.
s# specifies section number and is provided for backward compatibility;
the device file addresses the entire disk (s0) when s# is unspecified. (See