Senior Linux Administrator Knowledge Base
What this repository is
This is a practical reference library designed for administration, troubleshooting, incident response and long-term professional learning.
It is organized for two modes of use:
- Learning mode — understand how Linux components work and interact.
- Production mode — quickly diagnose a problem, choose safe next steps and verify recovery.
Operating principle
Observe → scope → form a hypothesis → collect evidence → make the smallest safe change → verify → document.
How notes are written
Most notes contain:
- Concept — what the technology does.
- Why it matters — operational impact.
- How it works — the mental model.
- Symptoms and failure modes.
- Investigation — commands and interpretation.
- Remediation and verification.
- Prevention and related topics.
Start with Troubleshooting Methodology, then explore by symptom or technology.