Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide

Glossary G–3
block A stream of data stored on a disk or tape media and transferred and
error-checked as a unit. In a disk drive, a block is 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.
cache memory A portion of high-speed memory used as an intermediary between a data user
and a larger amount of storage. The objective of designing cache into a
system is to improve performance by placing the most frequently used data in
the highest performance memory.
CBR An abbreviation used for Constant Bit Rate. CBR is a category of ATM
service. This category supports a constant (guaranteed) data rate. CBR
supports applications that require a highly-predictable transmission rate.
chunk A block of data written by the host.
See also block, chunk size
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.
CLI An abbreviation used to express the Command Line Interpreter. Also known
as Command Line Interface. The CLI is the configuration interface to operate
the controller software.
See command line interpreter.
connection A connection between two end Fibre Channel ports. An example would be
the connection between a Host Bus Adapter (by way of the Fibre Channel
Switches) and the HSG80 controller.
CLI commands available are ADD CONNECTIONS, SET connection-name.
See also link.
container 1. Any entity that is capable of storing data, whether it is a physical device
or a group of physical devices.
2. A virtual internal controller structure representing either a single disk or a
group of disk drives linked as a storageset (stripesets and mirrorsets are
examples of storageset containers the controller uses to create units).