30 Must‑Know Linux Operations Interview Questions from Sohu

As a Linux Operations Engineer, joining a large company can be a pivotal career step. Below are the Sohu Linux Operations Engineer job requirements and a collection of interview questions shared to assist job seekers.

Job Definition and Requirements

Position: System Operations Engineer

Salary: 15K‑35K

Location & Experience: Beijing, 3‑5 years, Bachelor’s degree or higher, full‑time

Job Description:

Build advanced storage and message‑queue distributed systems for Sohu International.

Develop container technologies and improve elastic scaling services to boost resource utilization and operational efficiency.

Develop core service components to address common needs and reduce duplicate development and operations.

Qualifications:

Proficient in 1‑2 languages on Linux (C/C++, Go, Python, Shell, etc.).

Understanding of distributed system principles, with deep knowledge of storage, queues, or elastic computing.

Solid technical foundation covering performance, availability, scalability, security, monitoring, and CI/CD.

Experience with at least one of: memcached, Redis, LevelDB, RocksDB, MySQL, Kafka, Docker (preferred).

Clear thinking and proven rapid trouble‑shooting experience in production environments.

Interview Questions

How to determine whether MySQL master‑slave replication is synchronized, and how to make it synchronized?

How does InnoDB locate lock issues, and how to reduce master‑slave replication delay?

Explain the OSI seven‑layer model, TCP three‑way handshake, TCP connection termination, and when TCP enters TIME_WAIT.

What is cross‑site scripting, its hazards, and how to prevent SQL injection attacks?

How to store massive files?

How to reset the MySQL root password?

Replace the string "magedu" with "magestudy" in all *.txt files under /data and its subdirectories.

Create directory /data/sohu, create file sohu.txt inside it, and write the string "inet addr : 10.1.0.8 Bcast : 10.1.0.255 Mask : 255.255.255.1" into file "magedu.txt" (without quotes).

Write a script to calculate the sum 1+2+3+…+100.

Can Apache and MySQL run on the same machine? How to check their ports and processes?

How to deploy four websites on one VM with domain names www.sohu1.net, www.sohu2.net, test1.magedu.net, test2.magedu.net?

List the top ten IPs with the highest access count in /var/log/nginx/access.log.

How to view the number of connections per IP, disk I/O, and network I/O on the current system?

Write a script to batch‑add 20 users (user1‑20) with passwords consisting of "user" followed by five random characters or digits.

When dmesg shows "ip‑conntrack: table full, dropping packet", how to resolve it?

Advantages and disadvantages of caching in Varnish, Nginx, and Squid.

Explain the deep structure of DNS.

Describe the three modes of LVS.

Advantages and disadvantages of LVS, Nginx, and HAProxy.

Linux system monitoring commands for CPU load, memory, etc.

Commands to view network traffic.

Four Docker network modes.

High‑availability tools available.

MySQL backup tools.

Differences between Awk and SED.

Purpose of CDN.

How KeepAlive works and how to perform health checks.

Default cache size of Squid.

Command to view all Linux system configurations (excluding CPUInfo and MEInfo).

Shell command to move files larger than 15KB from /opt to /tmp.

Examples of Python scripts you have written.

Note: These questions reflect one candidate’s experience and may differ from actual interview content; it is advisable to review multiple sources to improve interview success.