Linux Troubleshooting for DevOps
Troubleshoot real Linux production issues: high CPU, disk full, service failures, and port conflicts.
Progress Level
Intermediate (66%)
Estimated Time
Reading time: 8 minutes
Skill Outcome
Triage
Primary keyword: linux troubleshooting for devops | Secondary: linux production debugging, devops incident linux
A. Quick Clarity (2-3 min read)
What is this topic? Linux Troubleshooting for DevOps
Why important? Troubleshoot real Linux production issues: high CPU, disk full, service failures, and port conflicts.
Where used? Production systems on cloud platforms like Amazon Web Services, with containers and orchestration.
What you will learn? Core concept, practical flow, troubleshooting, and interview-ready understanding.
Cloud example: Amazon Web Services (AWS)
B. Concept Explanation
Core idea: Incident Workflow.
Analogy: Think of DevOps as a delivery highway where code moves from idea to production with checkpoints.
Architecture flow: User -> Application -> Container -> Kubernetes -> Cloud -> Monitoring
- Triage
- Evidence collection
- RCA
- Fix
- Prevention
C. Practical Section
Hands-on commands and examples for real usage.
Command Table
ls -la
systemctl status nginx
journalctl -u nginx --since "15 min ago"
D. Real DevOps Context
- Used in production delivery pipelines and cloud operations.
- Common platforms: Amazon Web Services, Docker, Kubernetes.
- Common mistake: jumping to advanced tools before concept clarity.
- Industry use: teams use this to improve release speed and reliability.
E. Troubleshooting
CrashLoopBackOff
Why it happens: Container startup failed due to missing env/config dependency.
How to fix: kubectl get pods | kubectl describe pod <pod> | kubectl logs <pod> --previous
502 Bad Gateway
Why it happens: Upstream app process not listening on expected port.
How to fix: sudo nginx -t | ss -lntp | curl -I http://localhost:<port>
High CPU
Why it happens: Hot endpoint and insufficient resource limits.
How to fix: top | ps aux --sort=-%cpu | head | kubectl top pod
F. Mini Practice Task
Try this now: Create a new Linux user, set folder permissions, and verify a service log.
Incident Workflow
- Triage
- Evidence collection
- RCA
- Fix
- Prevention
Common Failures
- Service not starting
- Port in use
- Disk pressure
- Memory pressure
FAQ
What is the first step in Linux incidents?
Start with service status, logs, and resource checks before making changes.