SQL Database Concepts Question:

RAID stands for Redundant array of independent disks which was earlier called as Redundant array of inexpensive disks. It is a storage technology that has one logical unit consisting of multiple disk drive components. It increases the performance by replicating and dividing the data through many levels between multiple physical drives. There are 12 Raid Levels which are as follows:
- Level 0: it is a 'striped' disk array (provides data stripping) without fault tolerance.
- Level 1: It is used in system for “mirroring” and “duplexing” purpose.
- Level 2: in this error correction takes place
- Level 3: it provides byte level stripping also called as “bit-interleaved parity”
- Level 4: is used as “dedicated parity drive” and it provides block level striping
- Level 5: is “block interleaved distributed parity”
- Level 6: is “independent data disks with double parity.
- Level 0+1: is “a mirror of stripes” and used for replication and sharing of data among disks
- Level 10: is “a stripe of mirrors”. Multiple mirrors are created and then stripes over it.
- Level 7: It adds caching to Level 3 or 4.
- Level 50: implemented as striped array with fault tolerance
- RAID S: it is proprietary striped parity RAID system