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.
A system administrator suspects a disk failure. Which TWO commands can be used to check disk health and identify bad sectors?
iostat -x
Why wrong: Shows I/O statistics, not bad blocks.
fsck /dev/sda
Why wrong: Filesystem check, not hardware health.
badblocks -v /dev/sda
Correct: Scans for bad sectors.
smartctl -a /dev/sda
Correct: Shows S.M.A.R.T health information.
dd if=/dev/sda of=/dev/null
Why wrong: Reads all data but does not identify bad sectors.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
badblocks -v /dev/sda
The `badblocks` command (option C) directly scans a disk for defective sectors by performing read/write tests, making it a primary tool for identifying bad blocks. The `smartctl -a` command (option D) queries the disk's S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) data, which includes attributes like reallocated sector count and pending sector errors, providing a proactive health assessment. Together, they cover both active scanning and passive monitoring of disk health.
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.
iostat -x
Why it's wrong here
Shows I/O statistics, not bad blocks.
fsck /dev/sda
Why it's wrong here
Filesystem check, not hardware health.
badblocks -v /dev/sda
Why this is correct
Correct: Scans for bad sectors.
Related concept
Read the scenario before looking for a memorised answer.
smartctl -a /dev/sda
Why this is correct
Correct: Shows S.M.A.R.T health information.
Related concept
Read the scenario before looking for a memorised answer.
dd if=/dev/sda of=/dev/null
Why it's wrong here
Reads all data but does not identify bad sectors.
Common exam traps
The trap here is that candidates confuse filesystem repair tools like `fsck` with hardware diagnostic tools, or assume `iostat` or `dd` provide equivalent health checks, when only `badblocks` and `smartctl` directly assess physical disk integrity.
Trap categories for this question
Command / output trap
Shows I/O statistics, not bad blocks.
Detailed technical explanation
`badblocks` can run in non-destructive read-only mode (`-sv`) or destructive write/read mode (`-w`), and its output can be fed to `e2fsck` via `-l` to mark bad blocks in the filesystem. S.M.A.R.T. attributes like 5 (Reallocated_Sector_Ct), 197 (Current_Pending_Sector), and 198 (Offline_Uncorrectable) provide early warning of physical degradation; `smartctl -a` parses these raw values and thresholds. In practice, a drive may pass `badblocks` but show elevated pending sectors in S.M.A.R.T., indicating imminent failure.
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.
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FAQ
Troubleshooting — This question tests Troubleshooting — Read the scenario before looking for a memorised answer..
The correct answer is: badblocks -v /dev/sda — The `badblocks` command (option C) directly scans a disk for defective sectors by performing read/write tests, making it a primary tool for identifying bad blocks. The `smartctl -a` command (option D) queries the disk's S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) data, which includes attributes like reallocated sector count and pending sector errors, providing a proactive health assessment. Together, they cover both active scanning and passive monitoring of disk health.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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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.
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