SurfRAID LC16 Series User’s
Manual
45
RAID
A
Redundant Array of Independent Disks
(RAID or RAID array) is a disk array in which part
of the storage capacity is used to store redundant information about user data stored on the
remainder of the storage capacity. The redundant information enables regeneration of user data in
the event that one of the array’s member disks or the access path to it fails.
RAID levels
The original RAID level 1 through 5 was outlined in a research paper entitled
A Case for Redun-
dant Arrays of Inexpensive Disks
. This paper was published in 1988 by David A. Patterson,
Garth Gibson, and Randy H. Katz of the University of California at Berkley. Counting the term
RAID 0 that refers to disk striping and later defined RAID 6, there are 7 levels of RAID.
SCSI
Small Computer System Interface.
SCSI ID
Also called SCSI ID#, is an octal representation of the unique address assigned to a SCSI device.
Spare, Spare Disk
A disk reserved for substitution of a like entity in case of the failure of that entity.
Swap
The replacement of a defective unit with a new unit. Units are parts of a disk subsystem that may
either be field replaceable by a vendor service representative or consumer replaceable.
