XK0-006 Troubleshooting Practice Question
A system is experiencing high memory usage. The administrator wants to see a brief summary of memory usage in human-readable format, including buffers and cache. Which command is most appropriate?
⚠ Common exam trap
A common mix-up: candidates confuse memory tools with I/O tools: candidates see 'human-readable' and 'buffers and cache' and may pick /proc/meminfo or vmstat -s, but only free -h provides the brief, formatted summary the question demands.
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
✓
free -h
free -h is correct because it prints a concise summary of total, used, free, shared, buff/cache, and available memory in human-readable units (MiB/GiB), directly satisfying the requirement to include buffers and cache. The -h flag converts raw kilobytes into readable values, making it the most appropriate single command for a quick memory overview.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
free -h
Why this is correct
`free -h` reads `/proc/meminfo` and prints a concise table of total, used, free, shared, buff/cache and available memory, with the `-h` flag scaling values into human-readable units such as MiB and GiB. This satisfies the stem's requirement for a brief summary that explicitly includes buffers and cache.
- ✗
iostat -m
Why it's wrong here
iostat -m reports disk input/output throughput and utilisation in megabytes, carrying no memory, buffer or cache statistics at all. It tempts administrators because it shares the human-readable -m flag and is a familiar performance tool, but it would be correct when diagnosing storage throughput rather than memory pressure.
- ✗
cat /proc/meminfo
Why it's wrong here
/proc/meminfo exposes raw kernel counters in kilobytes, not a human-readable summary, and requires manual interpretation of MemFree, Buffers and Cached fields. It tempts administrators because it is the authoritative source those tools read, and it would suit scripted parsing where exact byte-level values matter more than readability.
- ✗
vmstat -s
Why it's wrong here
vmstat -s reports memory statistics as raw counts of kilobytes or pages, not human-readable units, so it fails the formatting requirement. It tempts administrators because it does summarise memory including buffers and cache, and it would be the right choice when comparing event counters over time rather than reading current usage.
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This XK0-006 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 XK0-006 exam.