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

Glossary–2 HSG60 ACS Solution Software Version 8.6 for Compaq Tru64 UNIX Installation and Configuration
Guide
bad block
replacement
Abbreviated BBR. A replacement routine that substitutes defect-free disk
blocks for those found to have defects. This process takes place in the
controller, transparent to the host.
backplane The electronic printed circuit board into which you plug subsystem
devices—for example, the SBB or power supply.
BBR See bad block replacement.
BIST See built-in self-test.
bit A single binary digit having a value of either 0 or 1. A bit is the smallest unit
of data a computer can process.
block Also called a sector. The smallest collection of consecutive bytes addressable
on a disk drive. In integrated storage elements, a block contains 512 bytes of
data, error codes, flags, and the block address header.
bootstrapping A method used to bring a system or device into a defined state by means of its
own action. For example, a machine routine whose first few instructions are
enough to bring the rest of the routine into the computer from an input device.
built-in self-test A diagnostic test performed by the array controller software on the controller
policy processor.
byte A binary character string made up of 8 bits operated on as a unit.
cache memory A portion of memory used to accelerate read and write operations.
CDU Cable distribution unit. The power entry device for StorageWorks cabinets.
The CDU provides the connections necessary to distribute power to the
cabinet shelves and fans.
channel An interface that allows high speed transfer of large amounts of data. Another
term for a SCSI bus. See also SCSI.
chunk A block of data written by the host.
chunk size The number of data blocks, assigned by a system administrator, written to the
primary RAIDset or stripeset member before the remaining data blocks are
written to the next RAIDset or stripeset member.
CLCP An abbreviation for code-load code-patch utility. This utility is used to
upgrade the controller and EMU software. It can also be used to patch the
controller software.