LFCSEssential CommandsSingle Linux VMMedium

Free disk space and stop a CPU hog

Scenario lfcs-cmd-003 · about 6 minutes · 7 points · 6 grader checks

Delete large old files selectively, release space held by a deleted but still open log without restarting its service, and find the service burning a CPU.

disk-space
find
lsof
deleted-files
top
performance

What you will practise

Find files by size and age
Release space held by a deleted open file
Identify a CPU-hungry service and stop it

Start this lab

With the CLI installed and signed in, this command provisions a fresh Ubuntu 24.04 LTS virtual machine on your Mac, applies the scenario setup and prints the task below.

goldenkube start lfcs-cmd-003

Task

The task text exactly as the CLI shows it. Solve it on the machine, then run goldenkube submit.

1. Delete every regular file under /var/tmp/lab that is larger than 100 MiB and was last modified more than 7 days ago. Keep all other files. 2. df reports far more space used on / than du can find. A running service holds a deleted file open. Release that space without stopping or restarting the service (it must keep its PID). 3. One service keeps a CPU busy. Write its unit name (for example name.service) to /root/cpu-hog.txt, then stop and disable it.

Requirements and details

Certification: LFCS · Linux Foundation Certified System Administrator
Domain: Essential Commands
Difficulty: Medium
Environment: Single Linux VM
Recommended time: 6 minutes
Points: 7
Grader checks: 6
Operating system: Ubuntu 24.04 LTS
Minimum CLI version: 0.1.0
Scenario version: 1
Published: 30 Oct 2026

Grading runs locally: 6 state checks read your machine when you submit; the scenario passes when every check passes. Hints, the reference solution and the check definitions are available only inside the CLI, not on this page.

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