CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingHard
A server uses a RAID 1 mirror consisting of two drives. One drive fails completely and is removed for replacement. Which statement accurately describes the current state of the array?
- AThe array continues operating normally using the remaining drive, but redundancy is lost
- BThe array automatically rebuilds using parity data stored across both drives
- CRead speeds double because only one drive is now being accessed
- DAll data is lost because RAID 1 requires both drives to function
Show answer & explanationAnswer & explanation
Correct answer: A. The array continues operating normally using the remaining drive, but redundancy is lost
RAID 1 mirrors data identically across two drives, so if one drive fails, the array keeps functioning using the surviving drive with full data intact, though it is running without redundancy until a replacement is installed and remirrored. RAID 1 uses no parity, so option C is incorrect, and losing a drive does not improve read performance.
Why the other options are wrong
- B. RAID 1 uses mirroring, not parity, so there is no parity data to rebuild from.
- C. Losing a drive reduces available read sources; it does not increase speed.
- D. RAID 1 is fault-tolerant to a single drive failure; data is not lost.
RAID 1 Single-Drive Failure
RAID 1 mirrors data across two drives; if one fails, the array remains functional on the surviving drive but loses fault tolerance until replaced.
- RAID 1 = mirroring, no parity
- Survives single drive failure
- Rebuild requires new drive + remirroring, not automatic parity recovery
Memory trick: Mirror, mirror on the wall — lose one, the twin covers all (for now).