HP SureStore E Disk Array 12H User's and Service Manual (C5445-90901, September 1999)

Glossary
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Glossary
I/O Operation An Input/Output (I/O) Operation is an operation initiated by a host
computer system during which data is either written to or read from a
peripheral.
Including A Disk The process of adding a Disk Module to the array configuration is
called Including A Disk. The disk array cannot use a Disk Module until
it has been included. Once included, the disk array begins using the
Disk Module for data storage, even if you have not created a Logical
Drive with the newly added disk capacity.
JBOD As opposed to disk enclosures that offer Data Redundancy, an
enclosure without a Disk Array Controller (or another type of RAID) is
called Just a Bunch Of Disks, or JBOD. When a JBOD enclosure has a
disk failure, data is lost.
Load Balancing See Balancing.
L-DRV See Logical Drive.
Logical Drive A Logical Drive is a portion of the array capacity that appears to the
operating system as a physical disk. The entire array capacity can be
divided into up to eight Logical Drives. Only capacity that has been
assigned to a Logical Drive is available to the operating system.
The data contained in each Logical Drive is spread across all disks in
the array, so there is no direct correlation between a Logical Drive and
any single physical disk in the array.
Logical Drive Number A unique number (0–7) assigned to each Logical Drive on the disk
array. This number is used by your operating system to identify each
array Logical Drive.
Loop Address The unique ID of a node in Fibre Channel loop topology, sometimes
referred to as a Loop ID. Also a status type in the FC Status Menu,
showing the Loop Address of the FC-SCSI MUX.
LUN Logical Unit Number. For consistency with UNIX terminology, LUN
is used interchangeably with Logical Drive. See Logical Drive.