Interview Questions

DevOps Interview Questions for 5 Years Experienced (Practical + Real-Time) For 5 years experience, companies mostly expect: Linux Administration AWS / Cloud Docker Kubernetes Terraform Jenkins CI/CD Monitoring Troubleshooting Production Support Automation Security Basics 1. Linux Interview Questions Q1. How do you check CPU and memory usage? top htop free -m vmstat sar Q2. How do you check disk usage? df -h du -sh * lsblk Q3. How do you find top memory consuming process? ps -aux --sort=-%mem | head top Q4. How do you check open ports? netstat -tulnp ss -tulnp lsof -i Q5. How do you troubleshoot server down issue? Practical Steps ping server-ip ssh user@server top df -h free -m journalctl -xe systemctl status nginx 2. AWS Interview Questions Q6. How do you check EC2 server status? aws ec2 describe-instances Q7. How do you copy file to S3? aws s3 cp file.txt s3://bucket-name/ Q8. How do you sync folders to S3? aws s3 sync /data s3://backup-bucket Q9. How do you troubleshoot Load Balancer...

Kubernetes Practical Commands for Critical Interview Questions 1. Check Cluster Information kubectl cluster-info kubectl get nodes kubectl get componentstatus kubectl version 2. Check All Resources kubectl get all -A kubectl get pods -A kubectl get svc -A kubectl get deploy -A kubectl get rs -A 3. Pod Troubleshooting Check Pod Status kubectl get pods kubectl get pods -o wide kubectl describe pod pod-name View Logs kubectl logs pod-name kubectl logs -f pod-name kubectl logs pod-name --previous Login Into Pod kubectl exec -it pod-name -- /bin/bash kubectl exec -it pod-name -- sh 4. CrashLoopBackOff Troubleshooting kubectl describe pod pod-name kubectl logs pod-name --previous kubectl get events --sort-by=.metadata.creationTimestamp 5. Pending Pod Troubleshooting Check Events kubectl describe pod pod-name kubectl get events Check Node Resources kubectl top nodes kubectl describe node node-name 6. Deployment Commands Create Deployment kubectl create deployment nginx --image=nginx Scale Dep...

Frequently Asked Production Commands kubectl get all -A kubectl describe pod kubectl logs kubectl exec -it kubectl top nodes kubectl top pods kubectl get events kubectl rollout history kubectl cordon kubectl drain kubectl uncordon If you want, I can also provide: * Kubernetes scenario-based interview questions * Kubernetes troubleshooting questions * Kubernetes networking deep-dive * Kubernetes real-time production issues * Kubernetes interview answers in practical manner * Kubernetes mock interview for experienced meantime u have to give the commands for each questions Critical Kubernetes Interview Questions with Practical Commands 1. How do you check cluster information? Commands kubectl cluster-info kubectl get nodes kubectl get componentstatus kubectl version Purpose * Check API server * Check scheduler * Verify cluster health 2. How do you check all resources in Kubernetes? Commands kubectl get all -A kubectl get pods -A kubectl get svc -A kubectl get deployments -A kubec...

1. Service Management (systemd) Q: How do you manage services in modern Linux? Answer: Using systemd Common commands: systemctl start nginx systemctl stop nginx systemctl restart nginx systemctl status nginx systemctl enable nginx systemctl disable nginx Q: Service is not starting. How will you debug? Answer: systemctl status journalctl -u Check: Syntax errors Port conflicts Permission issues Q: Difference between service and systemctl? service → old SysV init systemctl → modern systemd 🔹 2. Boot Process & Targets Q: Explain Linux boot process briefly Answer: BIOS → GRUB → Kernel → Init (systemd) → Services Q: How to change runlevel in systemd? Runlevels replaced by targets: systemctl get-default systemctl set-default multi-user.target systemctl isolate rescue.target 🔹 3. Process Management Q: How do you find high CPU process? top htop ps -aux --sort=-%cpu Q: Kill a process safely vs forcefully? kill -15 # graceful kill -9 # force Scenario: Q: Process keeps restarting au...

Q- How will you change the default user id value in Linux? Q- root# rm -rf /tmp/test gives error operation not permitted. Reason? Q- /etc/hosts (Which RPM is responsible for creating this file). Q- What is the difference between RPM and YUM? Q- What is the difference between Hard and Soft Link? Q- What is a sticky bit? Q- How will you check open ports on Linux Server? Q- How will you check open ports on remote servers (without login) Q- Your site is throwing 500 error, how will you start troubleshooting? Q- How will you start troubleshooting if your site is down? Q- How will you create space on disk if it is showing 100% used? Q- What is a package of sar command and what does it do?

Core Kubernetes Concepts 1. What happens when you run kubectl apply -f deployment.yaml? API server receives request Validates YAML Stores desired state in etcd Scheduler assigns Pod to node Kubelet pulls image & starts container 2. Difference between Deployment, StatefulSet, and DaemonSet? Deployment → stateless apps (web apps) StatefulSet → stateful apps (DBs like MySQL) DaemonSet → runs one pod per node (logging, monitoring agents) 3. What is etcd? Distributed key-value store Stores cluster state (source of truth) 4. What is a Pod? Smallest deployable unit Can have one or multiple containers Shares network + storage 🔹 Networking (Very Important) 5. How does Kubernetes networking work? Each Pod gets unique IP Flat network (no NAT between pods) Uses CNI plugins (Calico, Flannel) 6. Difference between ClusterIP, NodePort, and LoadBalancer? ClusterIP → internal access NodePort → exposes via node IP LoadBalancer → cloud external LB 7. What is Ingress? HTTP/HTTPS routing Works with In...