Compaq StorageWorks HSG60 ACS Solution Software V8.6 for Compaq Tru64 UNIX Installation and Configuration Guide

Glossary–14 HSG60 ACS Solution Software Version 8.6 for Compaq Tru64 UNIX Installation and Configuration
Guide
primary cabinet The primary cabinet is the subsystem enclosure that contains the controllers,
cache modules, external cache batteries, and the PVA module.
private NL_Port An NL_Port which does not attempt login with the fabric and only
communicates with NL_Ports on the same loop.
program card The PCMCIA card containing the controller operating software.
protocol The conventions or rules for the format and timing of messages sent and
received.
PTL Port-Target-LUN. The controller method of locating a device on the controller
device bus.
PVA module Power Verification and Addressing module.
quiesce The act of rendering bus activity inactive or dormant. For example, “quiesce
the SCSI bus operations during a device warm-swap.”
RAID Redundant Array of Independent Disks. Represents multiple levels of storage
access developed to improve performance or availability or both.
RAID level 0 A RAID storageset that stripes data across an array of disk drives. A single
logical disk spans multiple physical disks, enabling parallel data processing
for increased I/O performance. While the performance characteristics of
RAID level 0 is excellent, this RAID level is the only one that does not
provide redundancy. Raid level 0 storagesets are sometimes referred to as
stripesets.
RAID level 0+1 A RAID storageset that stripes data across an array of disks (RAID level 0)
and mirrors the striped data (RAID level 1) to provide high I/O performance
and high availability. This RAID level is alternatively called a striped
mirrorset.
RAID level 1 A RAID storageset of two or more physical disks that maintain a complete
and independent copy of the entire virtual disk's data. This type of storageset
has the advantage of being highly reliable and extremely tolerant of device
failure. Raid level 1 storagesets are sometimes referred to as mirrorsets.
RAID level 3 A RAID storageset that transfers data parallel across the array disk drives a
byte at a time, causing individual blocks of data to be spread over several disks
serving as one enormous virtual disk. A separate redundant check disk for the
entire array stores parity on a dedicated disk drive within the storageset. See
also RAID level 5.