174 Essential Operations Engineer Interview Questions to Boost Your Prep

After spending a week interviewing at dozens of internet companies—including IBM, Sina, and Perfect World—focusing on Linux, container operations, and automation, the author shares the interview questions encountered to help others.

The author is a DevOps engineer with three years of experience, currently working at IBM on Kubernetes, Prometheus, Grafana, and Vue/Python development, and enjoys sharing knowledge.

He emphasizes that beyond technical skills, clear and confident communication under pressure is crucial for securing offers.

174 Operations Engineer Interview Questions

1. What is operations? What is game operations?

2. In your work, operations staff often need to interact with product staff; what does a product staff do?

3. Given three hundred servers, how would you manage them?

4. Describe the principles and characteristics of RAID0, RAID1, and RAID5.

5. What are the differences among LVS, Nginx, and HAProxy, and how would you choose among them in practice?

6. What are the differences among Squid, Varnish, and Nginx, and how would you choose among them?

7. What are the differences between Tomcat and Resin, and how would you choose?

8. What is middleware? What is the JDK?

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

10. What is a CDN?

11. What is gray‑release (canary deployment) for a website?

12. Briefly describe the DNS domain resolution process.

13. What is RabbitMQ?

14. Explain the working principle of Keepalived.

15. Describe the three LVS operating modes and their processes.

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

17. How to reset the MySQL root password?

18. Compare the advantages and disadvantages of LVS, Nginx, and HAProxy.

19. What tools are used for MySQL data backup?

20. Explain Keepalive’s working principle and how it performs health checks.

21. How would you analyze Nginx access logs to list the top ten IPs by page views?

22. Use tcpdump to capture traffic on host 192.168.1.1, port 80, and save the output to tcpdump.log.

23. How would you forward requests from local port 80 to port 8080 on a host with IP 192.168.2.1?

24. Briefly describe the principles and characteristics of RAID0, RAID1, and RAID5.

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

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

27. A server fails to boot; outline step‑by‑step troubleshooting.

28. How would you handle a virus infection on a Linux system?

29. If a virus file reappears after deletion, how would you resolve it?

30. Explain the seven layers of the TCP/IP model.

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

32. List the web server load‑balancing architectures you know.

33. How to view the number of concurrent HTTP requests and their TCP connection states?

34. Use tcpdump to sniff port 80 traffic and identify the IP with the most requests.

35. Write a script that determines which IPs in the 192.168.1.0/24 network are online (pingable).

36. Apache logs are stored under /app/logs; due to disk space constraints, only the latest 7 days should be kept. Provide a solution or command.

37. How would you generally optimize a Linux system?

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

39. Explain the function of the following SecureCRT shortcut keys.

40. Schedule a nightly backup at 00:00 that archives /var/www/html into /data with a timestamped filename.

41. How to mount a Windows shared directory on Linux?

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

43. (Duplicate) Use tcpdump to sniff port 80 and find the top requester.

44. Count the number of files under /var/log.

45. Show the number of connections per IP on the current system.

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

47. List the top five IPs by request count in Apache’s access.log.

48. How to view the contents of a binary file?

49. In ps aux, what do VSZ and RSS represent?

50. Detect and repair /dev/hda5.

51. Describe the Linux boot sequence.

52. Difference between symbolic links and hard links.

53. How to save the current disk partition table?

54. Commands for copy, paste, delete lines, delete all, line‑wise search, and character‑wise search in a text file.

55. Manually install GRUB.

56. Extract lines 4 to 7 from file aaa.txt.

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

58. Find files larger than 1 MB under /usr.

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

60. Explain MySQL master‑slave replication principles.

61. How many modes does vim have?

62. Briefly describe the DNS resolution process for www.baidu.1.com.

63. Explain the two DNS query modes.

64. Describe forward proxy and reverse proxy.

65. Summarize ETCD and its characteristics.

66. Summarize scenarios where ETCD is applicable.

67. Summarize HAProxy and its features.

68. Summarize common load‑balancing strategies of HAProxy.

69. Compare Layer‑4 and Layer‑7 load balancing.

70. Compare LVS, Nginx, and HAProxy.

71. Briefly describe Heartbeat.

72. Briefly describe Keepalived and its working principle.

73. Outline the main modules of Keepalived and their functions.

74. How does Keepalived use health checks to ensure high availability?

75. Summarize the concept and purpose of LVS.

76. Describe LVS operating modes and processes.

77. List common LVS scheduling algorithms (load‑balancing strategies).

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

79. Define a proxy server and its role.

80. What two dimensions are used to measure high availability, and what do they mean?

81. Explain the CAP theorem.

82. Explain the ACID properties.

83. What is Kubernetes?

84. Describe the relationship between Kubernetes and Docker.

85. What are kube‑adm (or kube‑init), kubectl, and kubelet?

86. Common deployment methods for Kubernetes.

87. How does Kubernetes manage clusters?

88. Advantages, suitable scenarios, and characteristics of Kubernetes.

89. Current drawbacks or limitations of Kubernetes.

90. Basic concepts of Kubernetes.

91. Components of a Kubernetes cluster.

92. Explain the mechanism of a Kubernetes ReplicationController (RC).

93. Difference between a ReplicaSet and a ReplicationController.

94. Role of kube‑proxy.

95. How kube‑proxy works with iptables.

96. How kube‑proxy works with IPVS.

97. Differences between kube‑proxy IPVS and iptables modes.

98. What is a static Pod in Kubernetes?

99. Possible states of a Kubernetes Pod.

100. Main steps to create a Pod.

101. Restart policies for Pods.

102. Health‑check methods for Pods.

103. Common LivenessProbe implementations.

104. Typical scheduling strategies for Pods.

105. Purpose of an init container.

106. Upgrade process of a Deployment.

107. Upgrade strategies for Deployments.

108. Characteristics of a DaemonSet.

109. Automatic scaling mechanisms in Kubernetes.

110. Types of Services.

111. Backend routing strategies for Services.

112. What is a Headless Service?

113. How external clients can access services inside a cluster.

114. Explain Ingress.

115. Image pulling strategies in Kubernetes.

116. Load balancers used by Kubernetes.

117. How Kubernetes modules communicate with the API server.

118. Role and implementation principle of the Scheduler.

119. Two algorithms the Scheduler uses to bind Pods to nodes.

120. Role of kubelet.

121. Which component kubelet uses to monitor node resources.

122. How Kubernetes ensures cluster security.

123. Admission control mechanisms.

124. Features and advantages of RBAC.

125. Purpose of Secrets.

126. Ways to use Secrets.

127. Mechanism of PodSecurityPolicy.

128. Security policies achievable with PodSecurityPolicy.

129. Kubernetes network model.

130. CNI (Container Network Interface) model.

131. Principles of Kubernetes network policies.

132. Role of a funnel (likely typo, ignore).

133. Implementation principle of Calico networking.

134. Purpose of shared storage in Kubernetes.

135. Methods for data persistence in Kubernetes.

136. Difference between PV and PVC.

137. Lifecycle stages of a PV.

138. Supported storage provisioners.

139. CSM model (likely typo, ignore).

140. Process for adding a worker node to a cluster.

141. How Pods control node resource usage.

142. How Requests and Limits affect Pod scheduling.

143. What is the Metrics Server.

144. Using EFK stack for unified logging.

145. Graceful node shutdown procedures.

146. Concept of cluster federation.

147. What is Helm and its advantages?

148. Overview of OpenShift and its features.

149. Purpose of OpenShift projects.

150. How OpenShift achieves high availability.

151. SDN implementation in OpenShift.

152. Roles in OpenShift and their functions.

153. Authentication methods supported by OpenShift.

154. Definition of middleware.

155. Disk usage detection script (shell).

156. LVS load‑balancing strategies.

157. Your understanding of LVS.

158. Principles of load balancing.

159. Two components that make up LVS.

160. Terminology related to LVS.

161. Principle of LVS‑NAT mode.

162. Characteristics of LVS‑NAT model.

163. Principle of LVS‑DR mode.

164. Characteristics of LVS‑DR model.

165. Comparison of the three LVS load‑balancing modes.

166. LVS scheduling algorithms.

167. Differences between LVS and Nginx.

168. Functions of load balancing.

169. Nginx load‑balancing distribution strategies.

170. What is Keepalived?

171. Understanding of the VRRP protocol.

172. Working principle of Keepalived.

173. Causes of split‑brain (brain split) in clusters.

174. How to resolve Keepalived split‑brain issues.