HP Surestore Disk Array 12h - And FC60 Advanced User's Manual page 451

PROM (Programmable Read-Only Memory)
SP-resident boot code that loads the SP microcode from one of the disk array's
database drives when the disk array is powered up or when an SP is enabled.
RAID
An acronym for "Redundant Array of Independent Disks." RAID was developed to
provide data redundancy using independent disk drives. RAID is essentially a method
for configuring multiple disks into a logical entity (LUN) that appears to the host system
as a single, contiguous disk drive. RAID uses features such data striping, disk mirroring,
and parity to implement data redundancy. The RAID levels supported by the disk array
include RAID 1, RAID 3, and RAID 5.
RAID 0
A RAID level that provides improved performance through the use of data striping, but
does not provide any data redundancy. RAID 0 should only be used for non-critcal data
storage.
RAID 1
A RAID level in which the LUN uses a single mirrored pair of disks. One disk serves as
the data disk, and the other serves as the mirror disk.
RAID 0/1
A RAID configuration in which the LUN uses both mirroring for redundancy, and disk
striping for performance. Half the disks serve as the data disks, and half serve as the
mirror disks. Up to 30 disks can be included in a RAID 0/1 LUN.
RAID 5
A RAID configuration in which the LUN uses data parity to for redundancy, and disk
striping for performance. RAID 5 is efficient in its use of disk space, but suffers a
performance penalty when performing write I/Os. Up to six disks (one per enclosure)
can be used in a RAID 5 LUN.
rebuild
The process of reconstructing the data that was on a failed disk onto another disk,
typically a global hot spare. The disk array reconstructs the data using mirrored data or
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