LSI Series 518 144

Channel	An electrical path for the transfer of data and control information between
	a disk and a disk controller.
Consistency	An examination of the disk system to determine whether all conditions
Check	are valid for the speciﬁed conﬁguration (such as parity.)
Cold Swap	A cold swap requires that you turn the power off before replacing a
	defective disk drive in a disk subsystem.
Data Transfer	The amount of data per unit time moved through a channel. For disk I/O,
Capacity	data transfer capacity (bandwidth) is expressed in megabytes per second
	(Mbytes/s).
Degraded	Used to describe a disk drive that has become non-functional or has
	decreased in performance.
Disk	A nonvolatile, randomly addressable, rewritable mass storage device,
	including both rotating magnetic and optical disks and solid-state disks,
	or nonvolatile electronic storage elements. It does not include specialized
	devices such as write-once-read-many (WORM) optical disks, nor does
	it include so-called RAM disks implemented using software to control a
	dedicated portion of a host computer volatile random access memory.
Disk Array	A collection of disks from one or more disk subsystems combined with
	array management software. The software controls the disks and
	presents them to the array operating environment as one or more virtual
	disks.
Disk Duplexing	A variation on disk mirroring in which a second disk adapter or host
	adapter and redundant disk drives are present.
Disk Mirroring	Writing duplicate data to more than one (usually two) disk drives to
	protect against data loss in the event of device failure. Disk mirroring is
	a common feature of RAID systems.
Disk Spanning	Disk spanning allows multiple disk drives to function like one big drive.
	Spanning overcomes lack of disk space and simpliﬁes storage
	management by combining existing resources or adding relatively
	inexpensive resources. For example, four 36 Gbyte disk drives can be
	combined to appear to the operating system as one single 144 Gbyte
	drive. See also Array Spanning and Spanning.
Disk Striping	A type of disk array mapping. Consecutive stripes of data are mapped
	round-robin to consecutive array members. A striped array (RAID 0)
C-2	Glossary