Practice and reference
Read the concept, then use a quiz, builder or checklist to make it stick.
First response goal
The goal is to reduce uncertainty quickly. Confirm the symptom, gather evidence, avoid risky assumptions and create a clear next action.
Do not make destructive changes just to see what happens. That is not troubleshooting. That is jazz with root access.
Checklist
- Check filesystem usage
- Check inode usage
- Find largest directories
- Check logs and backups
- Avoid deleting unknown application data
- Record before and after sizes
Useful commands
$ df -h
$ df -i
$ du -xh /home | sort -h | tail -30
$ find /home -type f -size +500M -ls
What good notes include
- The exact symptom and timestamp.
- The command or tool used to verify it.
- Relevant output, trimmed and sanitised.
- What was ruled out.
- Recommended next action or escalation reason.
Customer-safe summary
Explain what was checked, what was found, and what the customer can do next. Avoid dumping raw logs unless they help. Clear beats clever.