Log Analysis & System Debugging

🧪 Log Analysis & System Debugging Lab 📌 Objective Read system logs like real incidents Identify root causes Debug common system failures ⚙️ Environment OS: Ubuntu Tools: journalctl, df, du, dmesg 🚨 Scenario 1: Service Crash Investigation Step 1 - Break the service sudo nano /etc/nginx/nginx.conf Add invalid line: invalid_directive; Restart: sudo systemctl restart nginx Step 2 - Investigate Check status: systemctl status nginx Check logs: sudo journalctl -u nginx -n 50 --no-pager ...

April 19, 2026 · 1 min

Grub2 Boot Recovery: Restoring a Server at 2AM

A step-by-step account of recovering a production server that dropped into the GRUB2 rescue shell at 2AM, resolved within SLA.

April 9, 2026 · 2 min