This LFCS practice question tests your understanding of storage management. 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.
An administrator receives a report that a specific directory /var/log is consuming too much disk space. Which command should be used to determine the total disk space used by that directory?
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.
df -h /var/log
Why wrong: df shows disk usage of the filesystem, not the directory.
ls -la /var/log
Why wrong: ls lists files but does not sum sizes recursively.
fdisk /var/log
Why wrong: fdisk is for partition manipulation, not directory size.
du -sh /var/log
du -sh calculates the total size of the directory.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
du -sh /var/log
Option D is correct because the `du -sh /var/log` command calculates the total disk space used by the specified directory. The `-s` flag summarizes the total size, `-h` provides human-readable output (e.g., in KB, MB, GB), and the path `/var/log` targets the directory in question. This is the standard Linux command for determining directory disk usage.
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.
df -h /var/log
Why it's wrong here
df shows disk usage of the filesystem, not the directory.
ls -la /var/log
Why it's wrong here
ls lists files but does not sum sizes recursively.
fdisk /var/log
Why it's wrong here
fdisk is for partition manipulation, not directory size.
du -sh /var/log
Why this is correct
du -sh calculates the total size of the directory.
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.
Common exam traps
The trap here is that candidates confuse `df` (filesystem-level usage) with `du` (directory-level usage), often selecting `df -h` because it shows disk space, without realizing it reports on the entire partition rather than the specific directory.
Trap categories for this question
Command / output trap
df shows disk usage of the filesystem, not the directory.
Detailed technical explanation
The `du` command works by traversing the directory tree and summing the sizes of all files and subdirectories, using the `stat()` system call to retrieve the `st_blocks` field (which represents the number of 512-byte blocks allocated on disk). This accounts for actual disk usage, including sparse files and indirect blocks, unlike the apparent size shown by `ls`. In real-world scenarios, `du -sh` is essential for identifying space hogs in directories like `/var/log` where log rotation may not be freeing space as expected.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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What to study next
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FAQ
Storage Management — This question tests Storage Management — Read the scenario before looking for a memorised answer..
The correct answer is: du -sh /var/log — Option D is correct because the `du -sh /var/log` command calculates the total disk space used by the specified directory. The `-s` flag summarizes the total size, `-h` provides human-readable output (e.g., in KB, MB, GB), and the path `/var/log` targets the directory in question. This is the standard Linux command for determining directory disk usage.
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.
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Last reviewed: Jun 25, 2026
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