SIIG US2265, Руководство пользователя

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RAID
2-1
Chapter 2
RAID
2-1 RAID Overview
Historically, the cost of implementing RAID in the small office
or home office environment has not been cost effective. When first
developed, RAID was an acronym for Redundant Array of
Inexpensive Drives. This, however, was changed to Redundant
Array of Independent Disks, for it was the more expensive
SCSI disk drives with superior performance and capacity which
captured the dominant share of the RAID market. But today’s
technology is changing, and the performance/capacity gap
between SCSI and ATA is quickly getting smaller. With the
increased performance of ATA/100 host controllers and higher
capacity ATA drives coming to market, the time is right to put ATA
RAID to work in the small office, home office environment and
CMD Medley (RAID-Monitoring utility in Windows) is just the
software to do that.
RAID was designed to greatly enhance two main categories of data
storage, performance and data integrity. RAID 0 (striping) can
actually increase the performance of sustained data transfer rates.
The second benefit of RAID is data redundancy. With RAID 1
(mirroring) an identical image of your data is placed on another
drive or set of drives. Should your main drive fail your data is
secure and available from the mirrored second drive.
For performance and data redundancy, use RAID 0+1
( stripping).
2-1.1 RAID 0 (striping)
Striping is a performance oriented, non-redundant data mapping
technique. It does not provide fault tolerance. Data is spread
accross all disks in the stripe set allowing multiple I/O operations
enhancing performance by taking advantage of today bus
mastering technology. The drawback is when one disk fails the
whole group fails. Two to four disks are required for striping.