Mirroring
A form of RAID in which
Array Management Software
maintains two or more identical
copies of data on separate disks.
MTBF
An abbreviation for
Mean Time Between Failure
, the average time from start of use to
failure in a large population of identical components or devices.
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
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
Redundant 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.
Spare, Spare Disk
A disk reserved for the purpose of substituting for a like entity in case of failure of that
entity.
Swap
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The installation of a replacement unit in place of a defective unit. Units are parts of a
disk controller that may either field replaceable by a vendor service representative or
consumer replaceable.