174 Must‑Know Operations Engineer Interview Questions

The author spent a week interviewing at dozens of internet companies (including IBM, Sina, and Perfect World) for Linux, container, and automation roles, and shares the interview questions encountered to aid others preparing for similar positions.

Sample Interview Questions

What is operations engineering? What is game operations?

What does an operations person do when working closely with product teams?

Given 300 servers, how would you manage them?

Explain the principles and characteristics of RAID0, RAID1, and RAID5.

What are the differences among LVS, Nginx, and HAProxy? How do you choose among them?

What are the differences among Squid, Varnish, and Nginx? How do you choose?

What are the differences between Tomcat and Resin? How do you choose?

What is middleware? What is the JDK?

Explain the purpose of Tomcat ports 8005, 8009, and 8080.

What is a CDN?

What is gray‑release for a website?

Describe the DNS domain resolution process.

What is RabbitMQ?

Explain how Keepalived works.

Describe the three LVS operating modes.

How does MySQL InnoDB locate lock issues? How to reduce master‑slave replication lag?

How to reset the MySQL root password?

Compare the pros and cons of LVS, Nginx, and HAProxy.

What tools exist for MySQL data backup?

How does Keepalive perform health checks?

How would you analyze Nginx access logs to find the top‑10 IPs by request count?

Write a tcpdump command to capture traffic on port 80 and save it to tcpdump.log.

How would you forward local port 80 traffic to port 8080 on a host with IP 192.168.2.1?

Explain the principles of RAID0, RAID1, and RAID5 again.

What is your understanding of the role of an operations engineer?

Provide a complete command to capture real‑time TCP 80 traffic.

Step‑by‑step troubleshooting for a server that fails to boot.

How to handle a virus infection on a Linux system?

What to do when a deleted virus file keeps re‑creating itself?

Describe the OSI seven‑layer model.

Which Nginx modules do you commonly use and for what purpose?

List common web server load‑balancing architectures.

How to view HTTP concurrent connections and their TCP states?

Use tcpdump to identify the IP with the most requests on port 80.

Write a script to list online IPs in the 192.168.1.0/24 network (ping‑based).

How to retain only the latest 7 days of Apache logs in /app/logs?

General tips for optimizing a Linux system.

Extract the IP address of eth0 using cut (or awk / sed).

Explain the function of a given SecureCRT shortcut command.

Schedule a nightly backup of /var/www/html to /data with timestamped archives.

How to mount a Windows shared directory on Linux?

How to view the number of files in /var/log?

How to view the number of connections per IP on the current system?

Generate a random 32‑bit password in a shell script.

Find the top 5 IPs by request count in an Apache access.log.

How to view the contents of a binary file?

What do VSZ and RSS represent in ps aux output?

How to detect and repair /dev/hda5?

Explain Linux boot order.

Difference between symbolic links and hard links.

How to save the current partition table.

Common text‑editing shortcuts: copy, paste, delete lines, search, etc.

Manual installation steps for GRUB.

Extract lines 4‑7 from aaa.txt.

List all files ending with .txt in the current directory.

Find files larger than 1 MB under /usr.

Write a cron job to run between 5 am and 8 am.

Explain MySQL master‑slave replication principles.

How many modes does Vim have?

Describe the DNS resolution process for www.baidu.1.com.

Two DNS query modes.

Difference between forward and reverse proxy.

What is ETCD and its characteristics?

Typical use cases for ETCD.

What is HAProxy and its features?

Common HAProxy load‑balancing strategies.

Difference between layer‑4 and layer‑7 load balancing.

Compare LVS, Nginx, and HAProxy.

Explain Heartbeat.

Explain Keepalived and its working principle.

Key modules of Keepalived and their functions.

How Keepalived ensures high availability via health checks.

Concept and purpose of LVS.

LVS working modes and processes.

Common LVS scheduling algorithms.

Pros and cons of LVS, Nginx, HAProxy.

What is a proxy server?

Metrics for measuring high availability.

What is the CAP theorem?

What is the ACID principle?

Brief overview of Kubernetes.

Relationship between Kubernetes and Docker.

Explain minikube, kubectl, and kubelet.

Common Kubernetes deployment methods.

How Kubernetes manages clusters.

Kubernetes advantages and suitable scenarios.

Current limitations of Kubernetes.

Basic Kubernetes concepts.

Kubernetes cluster components.

What is a ReplicationController?

Difference between ReplicaSet and ReplicationController.

Role of kube-proxy.

iptables vs. ipvs mode of kube-proxy.

Static Pods in Kubernetes.

Possible Pod states.

Pod creation workflow.

Pod restart policies.

Pod health‑check mechanisms.

LivenessProbe implementations.

Common Pod scheduling strategies.

Init containers purpose.

Deployment upgrade process and strategies.

DaemonSet characteristics.

Automatic scaling mechanisms.

Service types and backend routing strategies.

Headless Service concept.

External access to cluster services.

Ingress overview.

Image pull policies.

Kubernetes load balancer options.

How Kubernetes components communicate with the API server.

Scheduler role and algorithms.

Kubelet responsibilities and node monitoring.

Cluster security mechanisms.

Admission control concepts.

RBAC features and advantages.

Purpose and usage of Secrets.

PodSecurityPolicy mechanisms and policies.

Kubernetes networking model and CNI plugins (e.g., Calico).

Shared storage and persistent volume concepts.

PV/PVC lifecycle and storage classes.

Helm benefits.

OpenShift features, projects, high‑availability, SDN, roles, and authentication.

Disk usage detection via shell script.

LVS load‑balancing strategies and terminology.

VRRP protocol basics and keepalived brain‑split (split‑brain) handling.

The full list of 174 questions can be obtained from the original source.