The correct answer is that a full logging partition is causing log write failures, which directly explains the firewall performance issues. When the logging partition on a PA-500 reaches 100% utilization, the firewall cannot write new logs, forcing the system into a degraded state where processes stall or crash, leading to the performance degradation seen in the 'show system resources' output. On the Palo Alto Networks Certified Network Security Administrator PCNSA exam, this scenario tests your ability to interpret resource utilization metrics and link them to specific failure modes—a common trap is to blame CPU or memory spikes, but the logging partition is a dedicated mount point that fills independently. A key memory tip: think of the logging partition as a trash can—when it’s full, the system chokes because it can’t dump new data, so always check disk usage under the /opt/panlogs mount when troubleshooting firewall performance issues.
PCNSA Device Management and Services Practice Question
This PCNSA practice question tests your understanding of device management and services. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
show system resources
CPU: user 10% system 5% idle 85%
Memory: 4096MB total, 4000MB used
Disk /dev/sda1: 20GB, 19GB used
Logging partition: 100% used
Refer to the exhibit. An administrator runs 'show system resources' on a PA-500 firewall experiencing performance issues. Based on the output, what is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Logging partition full causing log write failures
The 'show system resources' output on a PA-500 firewall indicates that the logging partition is full, which directly causes log write failures. This is a common performance issue because when the logging partition reaches capacity, the firewall cannot write new logs, leading to system instability and performance degradation. Option D is correct because the output explicitly shows the logging partition at 100% utilization.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Disk space on system partition critically low
Why it's wrong here
Incorrect: System partition is 95% used but not full; logging partition is the issue.
✗
High CPU usage on management plane
Why it's wrong here
Incorrect: CPU is only 15% used, which is not high.
✗
Memory exhaustion on dataplane
Why it's wrong here
Incorrect: Memory usage is high but may not cause performance issues directly; logging partition is more critical.
✓
Logging partition full causing log write failures
Why this is correct
Correct: A full logging partition can severely impact performance and log collection.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often focus on CPU or memory usage as the primary cause of performance issues, overlooking the critical impact of a full logging partition, which is a common and specific failure mode on Palo Alto firewalls.
Detailed technical explanation
How to think about this question
The PA-500 firewall uses separate partitions for system, logs, and other data. When the logging partition reaches 100% capacity, the firewall's log-writing processes (e.g., syslog, traffic logs) fail, which can cause the management plane to become unresponsive or slow as it retries failed writes. In real-world scenarios, this often occurs when log rotation or archiving is misconfigured, or when log export to an external syslog server fails, causing logs to accumulate locally.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the PCNSA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Device Management and Services — This question tests Device Management and Services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Logging partition full causing log write failures — The 'show system resources' output on a PA-500 firewall indicates that the logging partition is full, which directly causes log write failures. This is a common performance issue because when the logging partition reaches capacity, the firewall cannot write new logs, leading to system instability and performance degradation. Option D is correct because the output explicitly shows the logging partition at 100% utilization.
What should I do if I get this PCNSA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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This PCNSA practice question is part of Courseiva's free Palo Alto Networks 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 PCNSA exam.
Question Discussion
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