LPIC-1 Administrative Tasks Practice Question
A system administrator needs to perform incremental backups of a large directory /data. The backup strategy requires a full backup every Sunday and incremental backups on weekdays. Which tar command satisfies this requirement using the --listed-incremental option?
⚠ Common exam trap
Test-takers frequently confuse timestamp-based options like `--newer` or `-N` with the snapshot-based `--listed-incremental` mechanism, assuming any time-based filter can achieve incremental backups, but only `-g` provides the metadata tracking needed for proper incremental archives.
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
✓
Full: tar -cvf /backup/full.tar -g /var/backup/snapshot /data; Incremental: tar -cvf /backup/incr.tar -g /var/backup/snapshot /data
The `--listed-incremental` (or `-g`) option in tar creates and uses a snapshot file to track changes between backups. By specifying the same snapshot file for both the full and incremental backups, tar automatically records which files have changed since the last full backup, enabling proper incremental backups without relying on timestamps or file modification times.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Full: tar -czvf /backup/full.tar.gz /data; Incremental: tar -czvf /backup/incr.tar.gz --after-date '1 day ago' /data
Why it's wrong here
--after-date is a synonym for --newer, comparing mtimes against a date rather than tar's snapshot file, so it cannot detect deletions or renames between runs. Date-based selection is tempting for daily archives, and would be correct when only files modified since a timestamp matter.
- ✗
Full: tar -cvf /backup/full.tar /data; Incremental: tar -cvf /backup/incr.tar -N 'last Sunday' /data
Why it's wrong here
The -N flag filters by file modification date, not by tar's snapshot file, so it cannot track which files changed since Sunday's run; --listed-incremental requires a shared snapshot file. Date filtering is tempting for simple time-window backups, and would be correct if backups were purely time-based.
- ✗
Full: tar -cvf /backup/full.tar --newer /data; Incremental: tar -cvf /backup/incr.tar --newer /backup/full.tar /data
Why it's wrong here
--newer compares file timestamps against a reference file or date, not against tar's snapshot state, so deleted and renamed files are missed; --listed-incremental needs a snapshot file. --newer is tempting for date-based archiving, and would be correct for backing up files modified after a given date.
- ✓
Full: tar -cvf /backup/full.tar -g /var/backup/snapshot /data; Incremental: tar -cvf /backup/incr.tar -g /var/backup/snapshot /data
Why this is correct
The -g flag with a shared snapshot file lets tar record file states, so the first run captures everything and later runs store only changes since that snapshot. Reusing /var/backup/snapshot across both commands satisfies the full-then-incremental requirement.
Go deeper
Related to this question
About these practice questions
One of 402 original LPIC-1 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This LPIC-1 practice question is part of Courseiva's free LPI 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 LPIC-1 exam.