Google PCA Manage and provision cloud infrastructure Practice Question
A company is migrating a stateful application to Google Cloud. The application requires persistent disks with low latency and high IOPS for database workloads. They plan to use Compute Engine instances with SSD persistent disks. However, the database performance is lower than expected. Which action should the company take to improve disk performance?
⚠ Common exam trap
Watch out — candidates often assume increasing persistent disk size is the only way to improve IOPS, overlooking that local SSDs provide dramatically higher performance by being directly attached to the instance, and that RAID 0 is a common technique to aggregate their performance.
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
✓
Use local SSDs with RAID 0 configuration for the database data.
Local SSDs provide the highest IOPS and lowest latency of any disk option on Compute Engine, and striping them with RAID 0 aggregates their performance. This directly addresses the need for high IOPS and low latency for database workloads, unlike persistent disks which have performance ceilings tied to disk size and instance limits.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Change the persistent disk type to standard persistent disk.
Why it's wrong here
Standard persistent disks are HDD-backed, delivering lower IOPS and higher latency than SSD persistent disks, so this reverses the required direction. Standard PD suits sequential, throughput-oriented workloads where cost matters and random-access latency is not critical, not a database needing high random IOPS.
- ✗
Increase the disk size to increase baseline IOPS.
Why it's wrong here
SSD persistent disk IOPS scale with provisioned capacity, but the stem already specifies SSD persistent disks performing below expectation, so resizing alone does not address the underlying limit. Increasing size is valid when a disk is genuinely undersized for its baseline IOPS, not when the bottleneck lies elsewhere.
- ✓
Use local SSDs with RAID 0 configuration for the database data.
Why this is correct
Local SSDs attach directly to the host, delivering far lower latency and higher IOPS than persistent SSD disks. RAID 0 stripes data across multiple local SSDs, multiplying throughput to meet the database workload's performance requirement.
- ✗
Enable disk encryption to improve I/O throughput.
Why it's wrong here
Disk encryption protects data at rest and does not raise I/O throughput; it is a security control, not a performance lever. Encryption is the right choice when meeting compliance requirements for data-at-rest protection, not when diagnosing low IOPS on SSD persistent disks.
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
Learn chapter
Google Cloud Compute Options Overview
Key term
Latency
Latency is the time delay between a request being sent over a network and the response being received, often measured in milliseconds.
Key term
Compute Engine
Compute Engine is Google Cloud's Infrastructure-as-a-Service (IaaS) offering that lets you create and run virtual machines on Google's infrastructure.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA practice question is part of Courseiva's free Google Cloud 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 PCA exam.