XM Satellite Radio AA-RU5HC-TE Active virtual disk, Array controller See controller Block

glossary

This glossary defines terms used in this guide or related to this product and is not a comprehensive glossary of computer terms.

active virtual disk

A virtual disk is a simulated disk drive created by the controllers as storage for one or more hosts. An active virtual disk is accessible by one or more hosts for normal storage. An active virtual disk and its snapshot, if one exists, constitute a virtual disk family. An active virtual disk is the only necessary member of a virtual disk family.

See also virtual disk, virtual disk copy, virtual disk family, and snapshot.

array

All the physical disk drives in a storage system that are known to and under the control of a controller pair.

array controller See controller.

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.

cache

High-speed memory that sets aside data as an intermediate data buffer between a host and the storage media. The purpose of cache is to improve performance.

See also read cache, write cache, and mirrored cache.

command view EVA

A graphical user interface through which users control and monitor a storage system. The software can be installed on one or more management appliances in a fabric. Each Command View EVA installation is a management agent.

communication logical unit number (LUN)

See console LUN.

Command View EVA Storage System Scripting Utility Reference Guide 115