// linux fundamentals — start here
Linux Foundations — Start Here
This vault is a complete, ground-up course in how Linux actually works, built for someone learning it for the first time. It is designed as a chain: every module assumes total mastery of the one before it, and nothing else. If you follow the chain honestly, there is no point where you'll be asked to accept something on faith.
The original design document is Outline. The course itself is the files below.
The rules
- Go in order. The modules are a dependency graph flattened into a line. Module 5 uses vocabulary defined in Modules 0–4 without re-explaining it.
- Do every lab. The labs are not homework bolted onto the reading — they are the half of the lesson that happens in your terminal. Reading about
fork()teaches you a sentence; watching a process fork teaches you the concept. - Pass the mastery check before moving on. Every module ends with a Mastery Check: questions you must be able to answer out loud, without notes, and tasks you must be able to perform cold. If you can't, re-read the relevant section and redo the lab. This is the whole mechanism that makes the course work — do not skip it.
- Use a machine you're allowed to break. A virtual machine, a spare laptop, anything disposable. Several labs have you poke at things where a typo matters. Breaking a throwaway system is free and extremely educational.
The chain
| # | Module | What you'll be able to do afterward |
|---|---|---|
| 0 | Module 0 — What Linux Even Is | Say precisely what the kernel, userland, a shell, and a distribution each are |
| 1 | Module 1 — The Shell and the Command Line | Drive the system fluently from a terminal |
| 2 | Module 2 — The Kernel | Explain what the kernel does and watch it doing it |
| 3 | Module 3 — Everything Is a File | Navigate the whole filesystem tree and explain what a file really is |
| 4 | Module 4 — Users, Groups, and Permissions | Predict exactly what the kernel will allow or deny, and why |
| 5 | Module 5 — Processes, Signals, and IO | Create, steer, connect, and kill processes deliberately |
| 6 | Module 6 — The Boot Sequence | Name every stage from power button to login, and diagnose which one broke |
| 7 | Module 7 — systemd | Start, stop, inspect, write, and debug services; read the system journal |
| 8 | Module 8 — Networking on Linux | Map interfaces, routes, DNS, and listening services with Linux tools |
| 9 | Module 9 — Package Management and Shared Libraries | Explain how software is installed, how it breaks, and what Nix fixes |
| ★ | Capstone — Ready for NixOS | Prove the whole foundation, then step into NixOS |
Pace
One module per evening if you're pushing; one per few days at a casual pace. Speed is not the goal — never moving forward past something you half-understand is the goal. A wobbly Module 3 makes Modules 6, 7, and 9 miserable.