LFCS Storage Management Practice Question
An administrator needs to check the UUID of a filesystem on /dev/sdb1. Which command should be used?
⚠ Common exam trap
A common mix-up: candidates confuse `blkid` with `fdisk -l` or `df -h`, assuming those commands also display filesystem UUIDs, but only `blkid` (or `lsblk -f`) directly queries the superblock for this attribute.
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
✓
blkid /dev/sdb1
The `blkid` command is specifically designed to locate and display block device attributes, including the UUID and filesystem type. Running `blkid /dev/sdb1` queries the device's superblock and outputs its UUID, making it the correct tool for this task.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
df -h /dev/sdb1
Why it's wrong here
df shows space usage for mounted filesystems.
- ✗
mount | grep sdb1
Why it's wrong here
mount output shows mount points, device names and filesystem types, but not filesystem UUIDs. It is tempting because mount does display the device, so it appears to describe it. blkid reads the filesystem superblock directly and prints the UUID; that is the command this task requires.
- ✓
blkid /dev/sdb1
Why this is correct
`blkid /dev/sdb1` queries the block device directly, reading the filesystem superblock to report its UUID, TYPE and LABEL. It satisfies the stem's requirement to check the UUID of a specific partition without mounting it, and works regardless of whether the device is currently mounted.
- ✗
fdisk -l /dev/sdb1
Why it's wrong here
fdisk -l reports partition tables, sizes and types, not filesystem UUIDs, so it cannot answer the question. It is tempting because fdisk inspects the named block device directly, which feels relevant. blkid queries filesystem metadata and returns the UUID; lsblk -f also shows it.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.