LSI Series 518 146

Host Computer	Any computer to which disks are directly attached. Mainframes, servers,
	workstations, and personal computers can all be considered host
	computers.
Hot Spare	A stand-by disk drive ready for use if a drive in an array fails. A hot spare
	does not contain any user data. Up to eight disk drives can be assigned
	as hot spares for an adapter. A hot spare can be dedicated to a single
	redundant array, or it can be part of the global hot-spare pool for all
	arrays controlled by the adapter.
Hot Swapping	The substitution of a replacement unit in a disk subsystem for a defective
	one, where the substitution can be performed while the subsystem is
	running. Hot swaps are done manually.
I/O Driver	A host computer software component (usually part of the operating
	system) that controls the operation of peripheral controllers or adapters
	attached to the host computer. I/O drivers communicate between
	applications and I/O devices, and in some cases they participate in data
	transfer.
Initialization	The process of writing zeros to the data ﬁelds of a logical drive and
	generating the corresponding parity to put the logical drive in a Ready
	state. Initializing erases previous data and generates parity so that the
	logical drive will pass a consistency check. Arrays can work without
	initialization, but they can fail a consistency check because the parity
	ﬁelds have not been generated.
Logical Disk	A set of contiguous chunks on a physical disk. Logical disks are used in
	array implementations as constituents of logical volumes or partitions.
	Logical disks are normally transparent to the host environment, except
	when the array containing them is being conﬁgured.
Logical Drive	A virtual drive within an array that can consist of more than one physical
	drive. Logical drives divide the contiguous storage space of an array of
	disk drives or a spanned group of arrays of drives. The storage space in
	a logical drive is spread across all the physical drives in the array or
	spanned arrays. Conﬁgure at least one logical drive for each array.
Mapping	The conversion between multiple data addressing schemes, especially
	conversions between member disk block addresses and block addresses
	of the virtual disks presented to the operating environment by array
	management software.

C-4Glossary