Question 91 of 513
Essential CommandshardMultiple ChoiceObjective-mapped

LFCS Essential Commands Practice Question

This LFCS practice question tests your understanding of essential commands. 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 system administrator is managing a production web server running CentOS 7. The server hosts a critical application that depends on the 'httpd' package. Recently, the administrator attempted to install an updated version of httpd using 'yum update httpd', but the update failed with a dependency error: 'Error: Package: httpd-2.4.6-97.el7.centos.x86_64 requires libapr-1.so.0()(64bit)'. The administrator verifies that the apr package is installed (apr-1.5.2-6.el7.x86_64) and that the required library file exists at /usr/lib64/libapr-1.so.0. Despite this, yum continues to fail with the same error. After checking the yum repository configuration, the administrator notices that the base repository lists 'mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os' and the 'baseurl' is commented out. The system's /etc/yum.conf has 'keepcache=1'. What is the most likely cause of the dependency error, and which command should the administrator run to resolve it?

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.

  • Clue: "which command"

    Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.

Question 1hardmultiple choice
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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

The repository metadata is stale; run 'yum clean all' then 'yum update'.

Option A is correct. The dependency error despite the library being present suggests stale repository metadata. yum clean all clears the cache and forces fresh metadata download, which often resolves such false positives. Option B is incorrect because the apr version provides the required library. Option C is similar to A but manual deletion is unnecessary. Option D bypasses dependency checks and risks breaking the system.

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.

  • The yum cache is corrupted; delete /var/cache/yum manually and run 'yum makecache'.

    Why it's wrong here

    While corruption could cause issues, 'yum clean all' is the standard and safer approach.

  • The dependency is satisfied but yum's dependency resolver has a bug; use 'rpm -Uvh httpd.rpm --nodeps' to bypass dependency check.

    Why it's wrong here

    Bypassing dependencies is dangerous and not a correct resolution.

  • The repository metadata is stale; run 'yum clean all' then 'yum update'.

    Why this is correct

    Cleaning metadata refreshes dependency resolution, likely resolving the false error.

    Clue confirmation

    The clue words "most likely", "which command" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

  • The installed apr package is from a different version than what httpd expects; install a newer apr from a different repository.

    Why it's wrong here

    The installed apr provides the required library; version mismatch is unlikely.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.

Detailed technical explanation

How to think about this question

This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.

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.
  • Use explanations to understand the rule behind the answer.

TExam Day Tips

  • Underline the problem statement mentally.
  • 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 LFCS 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 LFCS exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

Related practice questions

Related LFCS practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this LFCS question test?

Essential Commands — This question tests Essential Commands — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: The repository metadata is stale; run 'yum clean all' then 'yum update'. — Option A is correct. The dependency error despite the library being present suggests stale repository metadata. yum clean all clears the cache and forces fresh metadata download, which often resolves such false positives. Option B is incorrect because the apr version provides the required library. Option C is similar to A but manual deletion is unnecessary. Option D bypasses dependency checks and risks breaking the system.

What should I do if I get this LFCS question wrong?

Identify which LFCS exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

Are there clue words in this question I should notice?

Yes — watch for: "most likely", "which command". 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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Last reviewed: Jun 24, 2026

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This LFCS practice question is part of Courseiva's free Linux Foundation 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 LFCS exam.