HP Surestore Disk Array 12h - And FC60 Service Manual page 265

I/O Operation
Including A Disk
JBOD
Load Balancing
L-DRV
Logical Drive
Logical Drive Number
Loop Address
LUN
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.
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.
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.
See Balancing.
See 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.
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.
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.
Logical Unit Number. For consistency with UNIX terminology, LUN
is used interchangeably with Logical Drive. See Logical Drive.
Glossary
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