Technical data

GL–9
Compaq HSG80 Array Controller ACS Version 8.3 Maintenance and Service Guide
IPI Intelligent Peripheral Interface. An ANSI standard for controlling peripheral
devices by a host computer.
IPI-3 Disk Intelligent Peripheral Interface Level 3 for Disk
IPI-3 Tape Intelligent Peripheral Interface Level 3 for Tape
JBOD Just a bunch of disks. A term used to describe a group of single-device
logical units.
kernel The most privileged processor access mode.
LBN Logical Block Number.
LED Light Emitting Diode.
link A connection between two Fibre Channel ports consisting of a transmit fibre
and a receive fibre.
logical block
number
See LBN.
local connection A connection to the subsystem using either its serial maintenance port or the
host’s SCSI bus. A local connection enables you to connect to one
subsystem controller within the physical range of the serial or host SCSI
cable.
local terminal A terminal plugged into the EIA-423 maintenance port located on the front
bezel of the controller. See also maintenance terminal.
logical bus A single-ended bus connected to a differential bus by a SCSI bus signal
converter.
logical unit A physical or virtual device addressable through a target ID number. LUNs
use their target’s bus connection to communicate on the SCSI bus.
logical unit number A value that identifies a specific logical unit belonging to a SCSI target ID
number. A number associated with a physical device unit during a task’s I/O
operations. Each task in the system must establish its own correspondence
between logical unit numbers and physical devices.