HP Surestore Disk Array 12h and FC60 - Manual (Page 448)

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host
A processor that runs an operating system using a disk array for data storage and
retrieval.
hot swappable
Hot swappable components can be removed and replaced while the disk array is online
without disrupting system operation. Disk array controller modules, disk modules,
power supply modules, and fan modules are all hot swappable components.
I/O operation
An operation initiated by a host computer system during which data is either written to
or read from a peripheral.
image (disk image)
See mirroring.
JBOD
An acronym for Just a Bunch Of Disks, it implies an enclosure that houses disk drives
that by themselves do not provide data redundancy. The disk systems on the disk array
are JBOD devices, but when connected to the disk array controllers, they provide data
redundancy through the use of RAID technology.
link
In Fibre Channel, two unidirectional fibres transmitting in opposite directions and their
associated transmitters and receivers that serve as the communication media between
nodes in a topology. A link is comparable to a bus in the SCSI protocol.
logical unit (LUN)
An acronym for Logical Unit Number, the SCSI term for logical disk unit. A logical unit
is an addressable part of a SCSI target. The terms “logical unit number” and “LUN” are
interchangeable.
The LUN is the basic storage entity created on the disk array. Each LUN appears to the
host as a single hard disk drive. Multiple LUNs, each using different RAID levels, can be