Question

Choose the correct answer from the options given below:
(A). RAID 3 requires only a single redundant disk.
(B) In RAID 4 scheme, two different parity calculations are carried out and stored in separate blocks on different disks.
(C) RAID 5 distributes the parity strips across all disks.
(D) In RAID 2, the number of redundant disks are proportional to the log of the number of data disks.

• A. (A) and(B) only.
• B. (B), (C) and (D) only.
• C. (A), (B) and (D) only.
• D. (A), (C) and (D) only.

Hint:

RAID 3 and 5 use parity, with RAID 5 distributing it across disks while RAID 3 uses a single parity disk. RAID 2 uses error correction codes that require a proportional number of redundant disks.

Answer 1

The Correct Option is D

RAID 3 correctly employs a single dedicated disk for array-wide parity information. The assertion that RAID 4 uses multiple blocks or disks for parity calculations instead of a dedicated parity disk is incorrect; RAID 4 necessitates a dedicated parity disk. RAID 5 correctly distributes parity strips across all disks through striping, thereby eliminating the need for a single parity disk. RAID 2 accurately utilizes Hamming code for error correction, where redundant disks are proportional to the log of data disks. Consequently, the correct answer is: (A), (C) and (D) only.