174 Must‑Know Ops Engineer Interview Questions (Free Download)

Operations development engineer with three years of experience, responsible for Kubernetes, Prometheus, Grafana operations and Vue/Python development, enjoys sharing knowledge and researching technology.

"Opportunities favor the prepared" – the essential knowledge for Linux operations engineers spans from basics to depth, especially under the cloud‑native trend.

174 Operations Engineer Interview Questions

What is operations? What is game operations?

In your work, operations staff often interact with product staff; what does product staff do?

Given three hundred 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 in practice?

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 JDK?

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

What is a CDN?

What is a gray‑release deployment?

Describe the DNS domain resolution process.

What is RabbitMQ?

Explain the working principle of Keepalived.

Describe the three LVS operating modes.

How does MySQL InnoDB locate lock issues, and how can MySQL reduce master‑slave replication lag?

How to reset the MySQL root password?

Advantages and disadvantages of LVS, Nginx, HAProxy.

MySQL backup tools.

How Keepalive works and performs health checks.

Analyze Nginx access logs to list the top ten IPs by page views.

Use tcpdump to capture traffic on host 192.168.1.1 port 80 and save to tcpdump.log.

Forward local port 80 requests to port 8080 on host 192.168.2.1.

Explain RAID0, RAID1, RAID5 principles and characteristics.

What is your understanding of the operations engineer role?

Write a command to capture and display real‑time TCP port 80 network data.

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

How to handle viruses on a Linux system.

If a virus file reappears after deletion, how to resolve?

Explain the OSI seven‑layer model.

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

List web server load‑balancing architectures you know.

How to view HTTP concurrent request count and TCP connection states.

Use tcpdump to sniff port 80 traffic and identify the top requester.

Write a script to determine which IPs in 192.168.1.0/24 are online (pingable).

Given Apache logs in /app/logs, keep only the most recent 7 days due to disk space constraints; provide a solution.

How to optimize a Linux system (general ideas).

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

Explain the function of the given SecureCRT shortcut keys.

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

How to mount a Windows shared directory on Linux.

View HTTP concurrent request count and TCP connection states (duplicate).

Use tcpdump to sniff port 80 traffic and identify the top requester (duplicate).

Count files in /var/log directory.

Show connection count per IP on the current system.

Generate a random 32‑bit password in shell.

List the top 5 IPs by access count in Apache access.log.

How to view the contents of a binary file.

Explain the meaning of VSZ and RSS in ps aux output.

Detect and repair /dev/hda5.

Linux boot sequence.

Difference between symbolic and hard links.

Save the current partition table.

Copy, paste, delete lines, delete all, search by line or character in a text file.

Manually install GRUB.

Extract lines 4‑7 from file aaa.txt.

List files ending with .txt in the current directory.

Find files larger than 1 MB under /usr.

Create 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.

Explain two DNS query modes.

Describe forward and reverse proxy.

Summarize ETCD and its characteristics.

Typical scenarios where ETCD is used.

Summarize HAProxy and its features.

Common HAProxy load‑balancing strategies.

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

Differences among LVS, Nginx, 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 role of LVS.

LVS operating modes and processes.

Common LVS scheduling algorithms.

Pros and cons of LVS, Nginx, HAProxy.

Concept and role of a proxy server.

Two dimensions to measure high availability and their meanings.

Explain the CAP theorem.

Explain the ACID theorem.

What is Kubernetes?

Relationship between Kubernetes and Docker.

Explain Minikube, kubectl, and kubelet.

Common Kubernetes deployment methods.

How Kubernetes manages clusters.

Advantages, applicable scenarios, and characteristics of Kubernetes.

Drawbacks or current limitations of Kubernetes.

Basic Kubernetes concepts.

Kubernetes cluster components.

Mechanism of Kubernetes ReplicationController.

Differences between ReplicaSet and ReplicationController.

Role of kube‑proxy.

iptables mode of kube‑proxy.

IPVS mode of kube‑proxy.

Differences between kube‑proxy IPVS and iptables.

What is a static Pod in Kubernetes?

Possible states of a Pod.

Main process of creating a Pod.

Pod restart policies.

Pod health‑check methods.

Common LivenessProbe implementations.

Typical Pod scheduling methods.

Init containers.

Kubernetes Deployment upgrade process.

Deployment upgrade strategies.

Features of DaemonSet resources.

Automatic scaling mechanisms in Kubernetes.

Kubernetes Service types.

Backend distribution strategies of Services.

Headless Service concept.

How external clients access services inside a cluster.

Ingress in Kubernetes.

Image download strategies.

Kubernetes load balancer.

How Kubernetes modules communicate with the API server.

Role and implementation of the Scheduler.

Two algorithms the Scheduler uses to bind Pods to nodes.

Role of kubelet.

Components kubelet uses to monitor node resources.

How Kubernetes ensures cluster security.

Admission control mechanisms.

Kubernetes RBAC features and advantages.

Purpose of Secrets.

Ways to use Secrets.

PodSecurityPolicy mechanism.

Security policies achievable with PodSecurityPolicy.

Kubernetes network model.

Kubernetes CNI model.

Kubernetes network policies.

Principles of network policies.

Role of the Kubernetes funnel.

Implementation principles of Calico network component.

Purpose of shared storage in Kubernetes.

Methods for persistent storage in Kubernetes.

PV and PVC concepts.

Lifecycle stages of a PV.

Supported storage provisioner models.

Kubernetes CSI model.

Process of adding a worker node to a cluster.

How Pods control node resource usage.

Impact of Requests and Limits on Pod scheduling.

Kubernetes Metric Service.

Using EFK for unified log management.

Graceful node shutdown maintenance.

Kubernetes cluster federation.

Helm and its advantages.

OpenShift features.

OpenShift projects and their purpose.

High‑availability implementation in OpenShift.

OpenShift SDN network implementation.

Roles in OpenShift and their functions.

Supported authentication methods in OpenShift.

What is middleware?

Disk usage detection with a shell script.

LVS load‑balancing strategies.

Your understanding of LVS.

Principles of load balancing.

Components of LVS.

Terminology related to LVS.

Principles of LVS‑NAT mode.

Characteristics of LVS‑NAT model.

Principles of LVS‑DR mode.

Characteristics of LVS‑DR model.

Comparison of the three LVS load‑balancing modes.

LVS scheduling algorithms.

Differences between LVS and Nginx.

Functions of load balancing.

Nginx load‑balancing distribution strategies.

What is Keepalived?

Understanding of the VRRP protocol.

Working principle of Keepalived.

Causes of split‑brain scenarios.

How to resolve Keepalived split‑brain issues.

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