HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide (EK-G80TS-SA. C01, March 2005)

Glossary
277HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide
BBR
Bad block replacement. 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.
BIST
Built-in self-test. A diagnostic test performed by the array controller software on the
controller policy processor.
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
A number of consecutive bytes of data stored on a storage device. In most storage systems,
a block is the same size as a physical disk sector. Also called sector.
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
See BIST.
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. The objective of caching
data in a system is to improve performance by placing the most frequently used data in the
highest performance memory.
cache module
A fast storage buffer.
CCITT
Consultive Committee International Telephone and Telegraph. An international association
that sets worldwide communication standards. Renamed International Telecommunications
Union (ITU).
CDU
Cable distribution unit. The power entry device for HP StorageWorks racks (cabinets). The
CDU provides the connections necessary to distribute power to the rack enclosures and
fans.