CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingMedium
A server uses a RAID 5 array of four disks. One disk fails and is hot-swapped with a new drive. Which statement best describes what happens during recovery?
- AThe array automatically converts to RAID 0 until manually reconfigured
- BThe array continues operating in a degraded state and rebuilds parity data onto the new disk
- CThe array is destroyed and must be rebuilt from a full backup
- DData is unrecoverable because RAID 5 cannot tolerate any disk failure
Show answer & explanationAnswer & explanation
Correct answer: B. The array continues operating in a degraded state and rebuilds parity data onto the new disk
RAID 5 uses distributed parity, allowing the array to survive a single disk failure. After replacing the failed disk, the controller rebuilds the missing data using parity information while the array runs in a degraded but functional state.
Why the other options are wrong
- A. RAID levels do not automatically change type during a rebuild.
- C. RAID 5 does not require a full restore for a single drive failure since parity allows rebuild.
- D. RAID 5 specifically tolerates exactly one disk failure using parity.
RAID 5 Fault Tolerance
RAID 5 stripes data with distributed parity across at least three disks, allowing the array to survive and rebuild after a single disk failure.
- Requires minimum 3 disks
- Tolerates exactly 1 disk failure
- Rebuild uses parity data to reconstruct lost disk contents
Memory trick: 'Parity Patches the Puzzle' — one missing piece can be rebuilt.