CV0-004 Troubleshooting Practice Question
A cloud engineer notices that an application is running slower than expected. Monitoring shows that the CPU utilization is consistently below 30%, but memory usage is at 95%. Which of the following is the most likely cause of the performance issue?
⚠ Common exam trap
The trap here is that candidates often associate performance issues solely with CPU or network bottlenecks, overlooking the severe impact of memory exhaustion and disk swapping, which can masquerade as a slow application with ample CPU headroom.
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
✓
Insufficient memory causing swapping to disk
When memory usage is at 95% and CPU utilization is low, the system is likely thrashing—the operating system is forced to page memory to disk (swap) to free RAM. Disk I/O is orders of magnitude slower than RAM, so even with idle CPU, the application stalls waiting for swap operations. This explains the performance degradation despite low CPU load.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Insufficient disk space for application logs
Why it's wrong here
Disk space exhaustion does not raise memory usage to 95% while leaving CPU idle; the symptom pattern indicates memory pressure, such as swapping or a leak. Insufficient disk is tempting because it also degrades performance, and would be correct if monitoring showed full volumes or write errors.
- ✓
Insufficient memory causing swapping to disk
Why this is correct
Insufficient memory forces the operating system to page data from RAM to disk, and that swapping introduces severe latency because disk access is orders of magnitude slower than memory. With memory at 95% while CPU sits below 30%, the bottleneck is memory pressure, not processing capacity, so adding RAM resolves the slowdown.
- ✗
Network bandwidth saturation
Why it's wrong here
Memory sits at 95% while CPU idles below 30%, so the bottleneck is memory pressure, not network throughput; bandwidth saturation would typically show elevated latency with normal memory. Network bandwidth is the right diagnosis when throughput counters approach the link's capacity during large transfers.
- ✗
CPU contention due to overprovisioning
Why it's wrong here
CPU utilisation is only 30%, so contention cannot explain the slowdown; overprovisioning would leave CPU idle, not memory exhausted. CPU contention is the correct diagnosis when host-level CPU ready time or steal time is high despite low guest utilisation.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CV0-004 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 CV0-004 exam.