Quick Answer
The answer is fsck -f /dev/sda2, which forces a filesystem check even if the superblock reports the volume as clean. After a power failure, the system logs indicate an unclean filesystem because the server was not properly unmounted, leaving metadata inconsistencies that a standard boot-time check might skip. The -f flag overrides this optimization, ensuring every inode and block is scanned for corruption on ext2/ext3/ext4 filesystems. On the CompTIA Linux+ XK0-005 exam, this scenario tests your understanding of emergency mode recovery and the distinction between a routine fsck and a forced check; a common trap is choosing fsck without -f, which may skip the repair if the filesystem is marked clean. Remember the mnemonic “Force after Failure” to recall that -f is mandatory after an unclean shutdown.
This XK0-005 practice question tests your understanding of troubleshooting. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
After a power failure, a Linux server boots into emergency mode. The system logs indicate an unclean filesystem on /dev/sda2. Which command should the administrator run to repair the filesystem?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
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.
fsck -f /dev/sda2
Correct: Forces filesystem check and repair.
badblocks /dev/sda2
Why wrong: Checks for bad blocks but does not repair filesystem.
xfs_repair /dev/sda2
Why wrong: Used for XFS filesystems, not the common ext4.
mount -o remount,ro /
Why wrong: Remounts read-only, does not repair filesystem.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
fsck -f /dev/sda2
After a power failure, the system logs indicate an unclean filesystem on /dev/sda2, meaning the filesystem was not properly unmounted and may contain inconsistencies. The `fsck -f /dev/sda2` command forces a filesystem check even if the filesystem appears clean, which is necessary to repair corruption on ext2/ext3/ext4 filesystems. This is the standard tool for checking and repairing such filesystems after an unclean shutdown.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
fsck -f /dev/sda2
Why this is correct
Correct: Forces filesystem check and repair.
Clue confirmation
The clue word "which command" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
badblocks /dev/sda2
Why it's wrong here
Checks for bad blocks but does not repair filesystem.
xfs_repair /dev/sda2
Why it's wrong here
Used for XFS filesystems, not the common ext4.
mount -o remount,ro /
Why it's wrong here
Remounts read-only, does not repair filesystem.
Common exam traps
The trap here is that candidates may confuse filesystem repair tools (fsck vs. xfs_repair) or mistake a disk surface scan (badblocks) for a filesystem consistency check, leading them to choose an inappropriate command for the specific filesystem type.
Detailed technical explanation
The `fsck` command (filesystem check) interacts with the filesystem's superblock and journal to replay or discard incomplete transactions, then scans inode and block bitmaps for cross-linked or orphaned blocks. For ext4, `fsck -f` forces a full check even if the filesystem's 'clean' flag is set, which is critical after an unclean shutdown because the journal may not have been replayed. In a real-world scenario, if the root filesystem itself is corrupted, you may need to boot from a live USB or use a rescue environment to run `fsck` on the unmounted partition.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the XK0-005 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
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Troubleshooting — study guide chapter
Learn the concepts, then practise the questions
Troubleshooting practice questions
Targeted practice on this topic area only
All XK0-005 questions
510 questions across all exam domains
CompTIA Linux+ XK0-005 study guide
Full concept coverage aligned to exam objectives
XK0-005 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise XK0-005 questions linked to Security.
Practise XK0-005 questions linked to Troubleshooting.
Practise XK0-005 questions linked to Scripting, Containers and Automation.
Practise XK0-005 questions linked to System Management.
Practise XK0-005 questions linked to XK0-005 fundamentals.
Practise XK0-005 questions linked to XK0-005 scenario.
Practise XK0-005 questions linked to XK0-005 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Troubleshooting — This question tests Troubleshooting — Read the scenario before looking for a memorised answer..
The correct answer is: fsck -f /dev/sda2 — After a power failure, the system logs indicate an unclean filesystem on /dev/sda2, meaning the filesystem was not properly unmounted and may contain inconsistencies. The `fsck -f /dev/sda2` command forces a filesystem check even if the filesystem appears clean, which is necessary to repair corruption on ext2/ext3/ext4 filesystems. This is the standard tool for checking and repairing such filesystems after an unclean shutdown.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
Last reviewed: Jun 25, 2026
This XK0-005 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 XK0-005 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.