RAID Concept

Raid Concept

1. Stripping

2. Mirroring

3. Parity

Stripping à process of breaking down data into pieces and distributing it across multiple disks that support a logical volume

- Better I/O performance

Mirroring -à process of writing the same data, to another “member” of the same volume simultaneously.

- Provides protection

Parity -à is the term for error checking.

Levels of RAID

RAID is s method of logically joining of two or more disks

RAID 0 : This level of RAID is a ‘normal’ file system with stripping, in which data loss is imminent with any disk failure.

- This gives good read/write performance but no recoverability.

- Minimum number of disks #2

RAID 1: Provides mirroring and hence full data redundancy.

- Mirroring, Recoverability, require write performance

- Minimum number of disks #2

RAID 5: Most common RAID implementation. Data redundancy is provided via parity calculations, but parity is stored along with the data.

- Recoverability, require read performance

- Minimum number of disks #3