ITPEC FE Subject A April 2026 Question 12
Which of the following is the RAID level that can maximize reliability and fault tolerance for a NAS device equipped with two hard disk drives of identical capacity?
Explanation
RAID 1 — mirroring, the only redundant RAID level that works with exactly two drives.
RAID 1 writes identical data to both disks, so either drive can fail without data loss. The cost is capacity: two drives give the usable space of one.
Answer (b)
Why not others:
- •(a) RAID 0 — striping for speed with no redundancy; losing either disk loses the whole array
- •(c) RAID 5 — distributed parity, needs at least 3 drives
- •(d) RAID 6 — double distributed parity, needs at least 4 drives
Key rule: Check the minimum drive count first: RAID 0 and 1 need 2, RAID 5 needs 3, RAID 6 needs 4; with two drives only mirroring gives fault tolerance.
System Component · AI-written, may contain errors
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