Define RAIDs And Their Usage?

RAID stands for "Redundant Array of Independent (or Inexpensive) Disks", it is  a category of disk drives that utilize two or more than two drives in combination or grouping for the "error or fault tolerance" and performance as well as presentation. The RAID disk drives are mostly used on servers but they are not normally essential for personal computers.  It is used as data storage scheme that split and replicate or reproduce data among various or multiple hard drives. It increases reliability of data and throughput. Raid is basically used to unite multiple hard disks into a single logic unit.

There are number of different RAID levels: 1- Level 0: Striped Disk Array without Fault Tolerance, 2- Level 1: Mirroring and Duplexing, 3- Level 2: Error-Correcting Coding, 4- Level 3: Bit-Interleaved Parity, 5- Level 4: Dedicated Parity Drive, 6- Level 5: Block Interleaved Distributed Parity, 7- Level 6: Independent Data Disks with Double Parity, 8- Level 0+1 : A Mirror of Stripes, 9- Level 10 : A Stripe of Mirrors, 10- Level 7, 11- RAID S

RAID can be done in two ways: either in hardware or in software. Hardware unites the drives into a single logical unit in dedicated hardware which further presents the drives as a single drive to an operating system. Software does this within an operating system and then presents the drives as a single drive to all of the users of the system.

Redundant Array Independent Disks is technique of making use of two or more hard disk drives in such that it forms a single unit. It does done so that there is no issue with computer's functioning as far as the prevention of data loss is concerned.

The major function of RAID is to increase the efficiency of the computer's performance as well as tolerating the fault which is associated with it. There are several levels of RAIDs available namely LEVEL 0, LEVEL 1, LEVEL 2, LEVEL 3, LEVEL 4, LEVEL 5 LEVEL 6, etc. Level 0 does not allow fault tolerance which means, if the system crashes i.e. if one drive malfunctions, then whatever data you had stored in it will be lost. LEVEL 1 is uses the technology of mirroring which means a copy of your data is created at the same time when it is created on the main drive. So, if there is a system crash, then you can go ahead and use the other drive.

For more information, visit the following link:
www.webopedia.comTERM/R/RAID.html.