The Linux+ Break Room
Somebody broke this box on purpose. It was me. Now it's your turn.
I'm working through CompTIA Linux+ (XK0-006), and just reading about Linux wasn't sticking. So I turned it into a game: a script sabotages a Linux box, and I have to work out what's wrong and fix it. This is that game, and I'm sharing it because Linux is my favourite hobby and it's way more fun with company. If one mission helps you get unstuck, or makes you grin when the fix finally works, that's a win for both of us.
How the game works
Run the saboteur
Each mission comes with a small script. It builds a sandbox inside one folder and quietly breaks a few things in it.
Play detective
You get the symptoms, not the solution. "The app won't start." "The disk is full." Figure out why, using nothing but the terminal.
Win on end state
Nobody grades the command you typed. If the app starts and the numbers are right, you won. Ten different fixes? All fine.
Reset and do it again
Run the script again and everything is broken again, fresh. The second time is where it really sticks.
🏠 House rules
- No surprises. Every mission tells you up front exactly what it touches and how to undo it. Early missions stay inside one folder; later ones (users, SSH, boot) say so loudly before you start.
- Never break the thing that lets you in. Missions that break services create throwaway ones. Your real SSH and network stay alone.
- Spare disks, never your disk. Disk missions turn ordinary files into real disks. Linux can't tell the difference, and your actual drive never gets involved.
- Read before you run. Never run a script from the internet without reading it first. Yes, that includes mine.
🖥️ Real shells, not click-through quizzes
No browser terminal that only accepts the "correct" answer, no click-through quiz pretending to be a server. Every mission runs on a real Linux shell, where the wrong command does exactly what a wrong command does.
I learned Linux on real servers: the kind that hum, crash at 2 a.m., and occasionally make you question your life choices. That's still how I like it. A real box lets you type the wrong thing and shows you exactly what happens next, and that moment is where the learning lives.
Old laptop, Raspberry Pi, a free VM on your PC, WSL, or a node in a virtual lab like CML or GNS3? All welcome. If it boots and it's got a shell, it's in.
Why a break room and not flashcards?
Flashcards told me what chmod 3770 means. Fixing a broken shared folder with my own hands made me remember it. When something is broken in front of you, your brain stops treating Linux like trivia and starts treating it like a puzzle. Puzzles are fun. Trivia is homework.
My box speaks Debian. The exam speaks everything.
I play on a Raspberry Pi running Debian, plus an old HP desktop for the things a Pi can't do, like a proper BIOS and bootloader. The exam doesn't care which Linux you use, so each mission points out where other families do it differently.
| Thing | Debian / Ubuntu | Red Hat family |
|---|---|---|
| Install software | apt, dpkg | dnf, rpm |
| Firewall | nftables, ufw | firewalld |
| Extra security layer | AppArmor | SELinux |
| Time sync | systemd-timesyncd | chronyd |
| Boot | GRUB 2 (update-grub); the Pi uses its own firmware | GRUB 2 (grub2-mkconfig) |
The 10 missions
They follow the five big areas the exam covers: system management, services and users, security, automation and scripting, and troubleshooting. Troubleshooting sneaks into every mission, because that's how real broken boxes work.
Past me deployed it wrong
An app that won't start, a messy day of logs, and a shared folder where anyone can delete anything.
Play mission →The service that keeps dying
It starts. It dies. It starts again. systemd is losing patience, and so are you.
The disk that's always full
Turn plain files into real disks, stack them into one big volume, then grow it while it's still in use.
Who let them in?
A stranger can use sudo, the real user can't log in, and the network config has a typo hiding in it.
The door left wide open
Every port is open and SSH happily accepts passwords from anyone. Close it all without locking yourself out.
It won't boot
Half-installed packages, a missing kernel module, and a bootloader to rescue on real hardware.
The bouncer says no
The permissions look perfect, yet something still says "Permission denied". Meet the security layer above permissions.
The script that lies
It prints "success" every single time. It is not successful. Catch the bugs in an overly optimistic bash script.
Robots on the night shift
The nightly job never ran, the git history is a mess, and the container refuses to start.
Everything is on fire
A bit of every mission, broken all at once. No hints. Just you, a shell and a hunch.
🗺️ Where I'm at
Mission 01 is playable today. The rest are being built and tested on my own boxes first, one at a time, as I work through them. If you want a particular one sooner, tell me. That's a great motivator.
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