3.4b - RAID: Professor Messer

Redundant Array of Independent Disks (RAID)

Technology used to combine multiple hard drives into a single unit for improved performance and redundancy.

Why RAID is not a backup

RAID uses data that is actively retrieved or stored - it is not a backup of data in a separate location.

RAID 0

Striping - a RAID system that stripes data evenly onto multiple disks to enhance performance but provides no redundancy.

RAID 1

Mirroring - a RAID system that mirrors data between two or more drives, offering high redundancy and requiring double disk space.

RAID 5

Striping with parity - a RAID system that stripes data across multiple drives while storing a single parity block for high redundancy and efficient space utilization.

RAID 6

Striping with double parity - RAID system that uses double parity blocks, allowing two drives to fail without data loss but may slow performance.

RAID 10 (RAID 1+0)

A stripe of mirrors - combines RAID 0 (striping) with RAID 1 (mirroring) for high redundancy and high speed, requiring at least four drives.

Data Redundancy in RAID

The ability to recover data after a drive failure, present in RAID 1, RAID 5, and RAID 6.

Performance Enhancement in RAID

The improved speed in data access and retrieval, primarily seen in RAID 0.

Parity in RAID systems

Extra data stored in RAID arrays that allow for data recovery in case of a single drive failure, used in RAID 5 and RAID 6.

RAID system requirements

Different RAID configurations require a specific number of drives, with RAID 10 needing at least four.