Lessons
Theory, a short quiz and practical work in each lesson. Independent troubleshooting incidents unlock after their prerequisite lessons; they are optional.
Linux Filesystem
Understand the idea, check your knowledge and practise in the terminal.
Check your Linux skills.
After fourteen hands-on checkpoints, take a twenty-question readiness check before twenty-two troubleshooting and storage labs. Every answer includes an explanation.
Choose one answer per question. You need at least 16 of 20 correct to unlock a passing result. Review the evidence behind each answer.
Investigate the incident
Twenty-two practical incidents across services, networking, Bash and storage. Gather evidence, select a root cause and — where possible — apply a fix. This is a controlled browser simulation, not a real Linux shell.
Storage scenarios 10–14 cover mounting and extending disks, LVM, deleted-open files and inode exhaustion. New scenarios 15–22 cover SSH, memory, systemd, firewall, packages, backups, I/O and Bash. Each mission checks your evidence, recovery steps and final diagnosis. All operations are simulated.
What is the root cause?
Investigate first; possible causes are hidden until you have collected enough supporting evidence.
The terminal is simulated and runs no real system commands. The diagnosis is checked against evidence available in this scenario.
GNU nano · editor
Edit the file in this simulated editor. No files on your computer are modified.
Training editor
Edit the file content in the virtual Linux system. This will not change any real files.
Glossary
Technical terms from Linux and the other planned DevOps modules, with short definitions and examples.
Technical terms
Learn concepts in context, save tricky words and revise them with flashcards.
Flashcard practice
All terms
Try another search term or choose a different topic.
Definitions are simplified for beginners. Continue with the course lessons and official documentation when you need deeper technical detail.