hardMultiple Choice
FC0-U71 Practice Question: Protect against data loss if a single hard drive…
A company wants to protect against data loss if a single hard drive fails. They have three identical drives. Which RAID configuration provides fault tolerance while maximizing storage capacity?
⚠ Common exam trap
It's easy for candidates to confuse RAID 5 with RAID 0 or RAID 1, mistakenly thinking striping alone (RAID 0) provides redundancy or that mirroring (RAID 1) maximizes capacity, when in fact RAID 5 is the only option among these that balances fault tolerance and storage efficiency with three drives.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
RAID 5
RAID 5 uses block-level striping with distributed parity, so if one of the three drives fails, the data can be rebuilt from the remaining drives plus the parity information. With three drives, RAID 5 provides fault tolerance for a single drive failure while using only one drive's worth of capacity for parity, maximizing usable storage (2/3 of total raw capacity).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
RAID 0
Why it's wrong here
RAID 0 stripes data across all three drives with no parity or mirroring, so any single drive failure loses the entire array. It tempts because it maximises usable capacity and performance, but the stem requires fault tolerance, which RAID 5 provides by distributing parity across the drives.
- ✗
JBOD
Why it's wrong here
JBOD concatenates all three drives into one logical volume, so any single drive failure destroys the entire array's data — no fault tolerance at all. It is tempting because JBOD maximises usable capacity by pooling every drive, which suits scratch storage or non-critical archives where capacity matters and redundancy does not.
- ✗
RAID 1
Why it's wrong here
RAID 1 mirrors data across paired drives, so with three identical disks the third sits unused or forms a second mirror, yielding only one drive's usable capacity rather than two. It is tempting because mirroring gives excellent fault tolerance, making RAID 1 the right pick when capacity is secondary to redundancy.
- ✓
RAID 5
Why this is correct
RAID 5 stripes data plus distributed parity across all three drives, so one drive failure is tolerated while usable capacity equals two drives, losing only one drive's worth. This satisfies both fault tolerance and maximum capacity, unlike mirroring which halves usable space.
Quick reference
RAID Level Comparison
| RAID Level | Min Disks | Fault Tolerance | Read | Write | Usable Capacity |
|---|---|---|---|---|---|
| RAID 0 | 2 | None | Excellent | Excellent | 100% |
| RAID 1 | 2 | 1 disk | Good | Moderate | 50% |
| RAID 5 | 3 | 1 disk | Good | Moderate | 67–94% |
| RAID 6 | 4 | 2 disks | Good | Lower | 50–88% |
| RAID 10 | 4 | 1 disk per mirror | Excellent | Good | 50% |
RAID is not a backup strategy — it protects against disk failure but not against accidental deletion, ransomware, or site-level events.
Go deeper
Related to this question
About these practice questions
One of 988 original FC0-U71 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This FC0-U71 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the FC0-U71 exam.