Section 14.124 Data Redundancy

Question 1

RAID (Redundant Array of Independent Disks)

Answer 1

Combines multiple physical storage devices into a single logical storage
device recognised by the operating system

Question 2

RAID 0

Answer 2

Provides data STRIPING across multiple disks

■ Used for improved performance but offers no data redundancy
■ Multiple drives increase read and write speeds
■ Suitable for scenarios where performance is essential, and data redundancy is not a concern

Performance without fault tolerance

Question 3

RAID 1

Answer 3

Provides redundancy by MIRRORING data identically on two storage devices

■ Ensures data integrity and availability
■ Suitable for critical applications and maintains a complete copy of data on both devices
■ Only one storage device can fail without data loss or downtime

Question 4

RAID 5

Answer 4

Utilises STRIPING WITH PARITY across at least three storage devices

■ Offers fault tolerance by distributing data and parity
■ Can continue operations if one storage device fails
■ Data reconstruction is possible but results in slower access speeds

Question 5

RAID 6

Answer 5

Similar to RAID 5 but includes double parity data. STRIPING WITH DOUBLE PARITY

■ Requires at least four storage devices
■ Can withstand the failure of two storage devices without data loss

Question 6

RAID 10

Answer 6

Combines RAID 1 (mirroring) and RAID 0 (striping). STRIPED ARRAY OF MIRRORED ARRAYS

■ Offers high performance, fault tolerance, and data redundancy
■ Requires an even number of storage devices, with a minimum of four

Question 7

RAID Resilience Categories

Failure-resistant

Answer 7

Resists hardware malfunctions through redundancy (e.g., RAID 1)

Question 8

RAID Resilience Categories

Fault-tolerant

Answer 8

Allows continued operation and quick data rebuild in case of failure (e.g.,
RAID 1, RAID 5, RAID 6, RAID 10)

Question 9

RAID Resilience Categories

Disaster-tolerant

Answer 9

Safeguards against catastrophic events by maintaining data in independent zones (e.g., RAID 1, RAID 10)

○ RAIDs are essential for ensuring data redundancy, availability, and performance in enterprise networks
○ The choice of RAID type depends on specific requirements for performance and fault tolerance