- A
passwd -S alice
Why wrong: Shows the password status, does not unlock.
- B
passwd -u alice
Why wrong: Not a standard command on all distributions; usermod -U is preferred.
- C
usermod -U alice
Correctly unlocks the user account password.
- D
chage -d 0 alice
Why wrong: Forces password change at next login but does not unlock an already locked account.
Question 466 of 513
LFCS User and Group Management Practice Question
This LFCS practice question tests your understanding of user and group 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.
After attempting to log in as user 'alice', the system rejects the password. The admin checks /etc/passwd and sees 'alice:x:1001:1001::/home/alice:/bin/bash'. The /etc/shadow shows 'alice:!!:18200:0:99999:7:::', indicating the account is locked. Which command will unlock the account?
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.
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
✓
usermod -U alice
Option C is correct because the `usermod -U alice` command unlocks the user account by removing the `!` from the password hash field in `/etc/shadow`. The `!!` in the shadow file indicates the account is locked (password disabled), and `-U` explicitly unlocks it, restoring the password hash to an active state.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
passwd -S alice
Why it's wrong here
Shows the password status, does not unlock.
- ✗
passwd -u alice
Why it's wrong here
Not a standard command on all distributions; usermod -U is preferred.
- ✓
usermod -U alice
Why this is correct
Correctly unlocks the user account password.
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.
- ✗
chage -d 0 alice
Why it's wrong here
Forces password change at next login but does not unlock an already locked account.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse `passwd -u` (which only unlocks accounts locked with `passwd -l`) with `usermod -U` (which handles all lock states, including those set via shadow file manipulation), leading them to choose option B incorrectly.
Trap categories for this question
Command / output trap
Shows the password status, does not unlock.
Detailed technical explanation
How to think about this question
Under the hood, the `!!` in the password hash field of `/etc/shadow` is a special marker that prevents any password from authenticating, effectively locking the account. The `usermod -U` command directly removes this marker, restoring the original hash (or setting it to an empty string if no hash existed). In real-world scenarios, admins often lock accounts during security incidents and must use `usermod -U` to re-enable login, as `passwd -u` may fail if the account was locked via `usermod -L` or shadow manipulation.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the LFCS 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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
User and Group Management — study guide chapter
Learn the concepts, then practise the questions
- →
User and Group Management practice questions
Targeted practice on this topic area only
- →
All LFCS questions
513 questions across all exam domains
- →
Linux Foundation Certified System Administrator LFCS study guide
Full concept coverage aligned to exam objectives
- →
LFCS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related LFCS practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
User and Group Management practice questions
Practise LFCS questions linked to User and Group Management.
Operation of Running Systems practice questions
Practise LFCS questions linked to Operation of Running Systems.
Essential Commands practice questions
Practise LFCS questions linked to Essential Commands.
Networking practice questions
Practise LFCS questions linked to Networking.
Service Configuration practice questions
Practise LFCS questions linked to Service Configuration.
Storage Management practice questions
Practise LFCS questions linked to Storage Management.
LFCS fundamentals practice questions
Practise LFCS questions linked to LFCS fundamentals.
LFCS scenario practice questions
Practise LFCS questions linked to LFCS scenario.
LFCS troubleshooting practice questions
Practise LFCS questions linked to LFCS troubleshooting.
Practice this exam
Start a free LFCS practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this LFCS question test?
User and Group Management — This question tests User and Group Management — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: usermod -U alice — Option C is correct because the `usermod -U alice` command unlocks the user account by removing the `!` from the password hash field in `/etc/shadow`. The `!!` in the shadow file indicates the account is locked (password disabled), and `-U` explicitly unlocks it, restoring the password hash to an active state.
What should I do if I get this LFCS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
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.
What is the key concept behind this question?
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
More LFCS practice questions
- A system administrator needs to ensure the Apache httpd service starts automatically on system boot. Which command shoul…
- Which THREE of the following are valid methods to mount an NFS filesystem on a client?
- Refer to the exhibit. The administrator wants to create a RAID 1 array using /dev/sdb1 and /dev/sdc1. Which command shou…
- A system administrator needs to list all files in the current directory, including hidden files, in a long listing forma…
- A user wants to find all files in /var/log that have been modified within the last 2 days. Which command should they use…
- A user needs to view the contents of a compressed log file /var/log/syslog.gz without first decompressing it. Which comm…
Last reviewed: Jul 4, 2026
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.
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.