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HSG80 Array Controller V8.7 Command Line Interface Reference Guide
Glossary–3
Glossary
BIST
Built-in self-test. A diagnostic test performed by the array controller software on the
controller’s 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.
CDU
Cable distribution unit. The power entry device for StorageWorks racks (cabinets). The CDU
provides the connections necessary to distribute power to the rack enclosures and fans.
channel
An interface which allows high speed transfer of large amounts of data. Another term for a
SCSI bus. See also SCSI.
chunk
In any form of RAID that stripes data, data is stored in pieces called chunks. One chunk is
stored on each member device in the unit. Taken together, the chunks make up a stripe. The
chunk size can be used in some controllers to tune the stripeset for a specific application.