Appendix D : Glossary - Accusys ACS-8910 User Manual

APPENDIX D : Glossary

Array Management Software, Firmware
The body of software that provides common control and management for a disk array. Array
Management Software most often executes in a disk controller or intelligent host bus adapter, but
may also execute in a host computer. When it executes in a disk controller or adapter, Array
Management Software is often referred to as Firmware.
Disk Array
A collection of disks from one or more commonly accessible disk controllers, combined with a
body of Array Management Software. Array Management Software controls the disks and
presents them to the array operating environment as one or more virtual disks.
Disk Striping
Data distributed across all the disks in the array. There is no redundant information generated
or stored.
Disk Mirroring
Data is duplicated on different sets of disks in the array.
Host Computer
Any computer system to which disks are directly attached and accessible for I/O. Mainframes,
and servers, as well as workstations and personal computers, can all be considered host
computers in the context of this book, as long as they have disks attached to them.
Hot Spare
The substitution of a replacement unit in a disk system for defective one, where the substitution
can be performed while the controller is running.
Hot Swap
The substitution of a replacement unit in a disk controller for a defective one, where the
substitution can be performed by the controller itself while it continues to perform its normal
function. Hot Swaps do not require human intervention (i.e., hot spare)
Member Disks
Disk channels configured for a particular RAID Level. Member disks are identified by a status
of " displayed on the front panel LCD.
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