VCP-DCV Configure and Manage vSphere Storage Practice Question
An administrator is configuring a vSAN cluster with all-flash capacity. The cluster uses RAID-5 erasure coding with a policy of 'Number of failures to tolerate = 1' (PFTT=1). The administrator wants to minimize storage overhead while ensuring availability. Which vSAN storage policy setting should be used?
⚠ Common exam trap
VCP-DCV often tests whether candidates know the minimum host requirements and overhead ratios for vSAN RAID-5 vs RAID-6, and candidates frequently pick RAID-1 assuming it is always the most efficient or forget that erasure coding requires all-flash.
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
✓
Set 'Primary level of failures to tolerate' to 1 and 'Primary level of failures to tolerate method' to 'RAID-5 (Erasure Coding)'
For an all-flash vSAN cluster with PFTT=1, RAID-5 erasure coding provides the lowest storage overhead (approximately 1.33x) while still tolerating one failure. Setting the primary level of failures to tolerate to 1 and the method to RAID-5 (Erasure Coding) achieves the administrator's goal of minimizing overhead while maintaining availability.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Set 'Primary level of failures to tolerate' to 1 and 'Primary level of failures to tolerate method' to 'RAID-1 (Mirroring)'
Why it's wrong here
RAID-1 mirroring consumes 50% of raw capacity, doubling every object, whereas RAID-5 erasure coding with PFTT=1 needs roughly 1.33x. Mirroring is tempting for its resilience and simplicity, and would be correct for clusters with fewer than four hosts, where RAID-5 is unavailable.
- ✗
Set 'Primary level of failures to tolerate' to 2 and 'Primary level of failures to tolerate method' to 'RAID-6 (Erasure Coding)'
Why it's wrong here
PFTT=2 with RAID-6 requires a minimum of six hosts and roughly 1.5x overhead, exceeding the stated PFTT=1 availability requirement. RAID-6 is tempting because it survives two simultaneous failures, and would be the right choice where the design genuinely demands that tolerance.
- ✓
Set 'Primary level of failures to tolerate' to 1 and 'Primary level of failures to tolerate method' to 'RAID-5 (Erasure Coding)'
Why this is correct
RAID-5 erasure coding with PFTT=1 delivers roughly 1.33x overhead versus 2x for RAID-1 mirroring, satisfying the all-flash minimum-overhead constraint while still tolerating one host failure. The policy must explicitly select the RAID-5 method, not RAID-1.
- ✗
Set 'Primary level of failures to tolerate' to 0
Why it's wrong here
PFTT=0 provides no redundancy, so a single host or disk failure loses data, violating the availability requirement. RAID-5 with PFTT=1 already tolerates one failure while consuming less capacity than RAID-1 mirroring, which is the correct choice when minimising overhead with guaranteed availability.
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.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official VMware exam blueprint
This VCP-DCV practice question is part of Courseiva's free VMware 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 VCP-DCV exam.