LFCS Operation of Running Systems Practice Question
This LFCS practice question tests your understanding of operation of running systems. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
A user reports that a background process (PID 3456) is consuming 95% of CPU and causing system slowness. The process name is 'crypto-miner'. The administrator needs to immediately stop this process and ensure it does not restart. Which set of commands should the administrator execute?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "immediately / without restart"
Why it matters: Time or reboot constraint — the correct answer must take effect right away without requiring a reboot or reload.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
kill -9 3456, then locate the cron job or systemd service that starts it, and disable/remove it.
Option A is correct because it addresses both immediate termination and persistence removal. The SIGKILL signal (kill -9) immediately terminates the process, and disabling the cron job or systemd service prevents automatic restart, which is critical for a malicious or unwanted process like 'crypto-miner'.
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.
✓
kill -9 3456, then locate the cron job or systemd service that starts it, and disable/remove it.
Why this is correct
Stops the process and prevents future launches.
Clue confirmation
The clue word "immediately / without restart" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
renice -n 19 -p 3456 and let it run with lower priority.
Why it's wrong here
Does not stop the process, still consumes CPU at lower priority.
✗
kill -9 3456 and then notify the user.
Why it's wrong here
Only stops the process temporarily; it may restart.
✗
kill -15 3456 and hope it terminates.
Why it's wrong here
SIGTERM may not stop the process; also doesn't prevent restart.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates focus only on stopping the process immediately (kill -9) and overlook the requirement to ensure it does not restart, leading them to choose an option that fails to address persistence.
Detailed technical explanation
How to think about this question
SIGKILL (signal 9) cannot be caught or ignored by the process, ensuring termination even if the process is unresponsive or malicious. Persistence mechanisms like systemd service units (with Restart=always) or cron jobs (with @reboot or periodic entries) must be identified and removed or disabled to prevent automatic restart. The 'systemctl disable' command or editing crontab with 'crontab -e' are typical methods for this.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
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.
Operation of Running Systems — This question tests Operation of Running Systems — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: kill -9 3456, then locate the cron job or systemd service that starts it, and disable/remove it. — Option A is correct because it addresses both immediate termination and persistence removal. The SIGKILL signal (kill -9) immediately terminates the process, and disabling the cron job or systemd service prevents automatic restart, which is critical for a malicious or unwanted process like 'crypto-miner'.
What should I do if I get this LFCS 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: "immediately / without restart". Time or reboot constraint — the correct answer must take effect right away without requiring a reboot or reload.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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