RAID

For applications that depend on reliable data access, it is crucial the data is available when a user attempts to access it. Some manufacturers develop a type of hard disk system that connects several smaller disks into a single unit that acts like a single large hard disk. A group of two or more integrated hard disks is called a RAID (redundant array of independent disks). Although quite expensive a RAID system is more reliable than a traditional disk system. Thus, networks and internet servers often use RAID.

RAID duplicates data, instructions and information to improve data reliability. RAID systems implement this duplication in different ways depending on the storage design or level used. (These levels are not hierarchical. That is higher level are not necessarily better than lower levels.) The simplest RAID storage design is level 1 called Mirroring, which has one backup disk for each disk. A level 1 configuration enhances system reliability because, if a drive should fail, a duplicate of the requested item is available elsewhere within the array of disks.

Levels beyond level 1 use a technique called STRIPPING, which splits data, instructions and information across multiple disks in the array. stripping improves disk access times, but does not offer data duplication. For this reason, some RAID levels combine both mirroring and stripping

Published by-mathshater
Contact me- mathshater