User manual

APPENDIX
166
• RAID 0
RAID 0, also referred to as striping, writes stripes of data across
multiple disk drives instead of just one disk drive. RAID 0 does
not provide any data redundancy, but does offer the best high-
speed data throughput. RAID 0 breaks up data into smaller blocks
and then writes a block to each drive in the array. Disk strip-
ing enhances performance because multiple drives are accessed
simultaneously; the reliability of RAID level 0 is less because the
entire array will fail if any one disk drive fails.
• RAID 1
RAID 1 is also known as “disk mirroring”; data written on one
disk drive is simultaneously written to another disk drive. Read
performance will be enhanced if the array controller can, in paral-
lel, access both members of a mirrored pair. During writes, there
will be a minor performance penalty when compared to writing
to a single disk. If one drive fails, all data (and software applica-
tions) are preserved on the other drive. RAID 1 offers extremely
high data reliability, but at the cost of doubling the required data
storage capacity.