🐧 Top 10 Linux Commands Every DevOps Engineer Must Know

Linux is the backbone of modern DevOps and cloud infrastructure. Whether you're managing servers, writing scripts, or troubleshooting production issues, knowing your way around the terminal is essential. In this blog, we'll cover the top 10 Linux commands that every DevOps engineer should know—especially if you're starting your journey into automation, CI/CD, and infrastructure management.

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1. top – Real-Time Process Monitoring

Use top to monitor system performance in real time. It shows CPU usage, memory usage, running processes, and system load.

top

🔧 Use Case: Quickly identify high-CPU or memory-hogging processes during server troubleshooting.

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2. ps – Process Snapshot

The ps command provides a snapshot of all currently running processes.

ps aux | grep nginx

🔧 Use Case: Find and investigate specific running services or applications.

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3. df – Disk Usage

Check available disk space on mounted filesystems using df.

df -h

🔧 Use Case: Monitor disk usage to prevent space-related outages.

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4. du – Directory Size

Find out how much space a directory or file is using.

du -sh /var/log

🔧 Use Case: Identify which files or directories are consuming storage.

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5. grep – Search Within Files

Grep is used to search for patterns in files or output streams.

grep "error" /var/log/syslog

🔧 Use Case: Search logs for errors, warnings, or specific events.

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6. chmod & chown – File Permissions

Manage file permissions (chmod) and ownership (chown).

chmod 755 script.sh
chown user:user file.txt

🔧 Use Case: Secure files and scripts by assigning proper access rights.

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7. systemctl – Manage Services

Use systemctl to start, stop, enable, or check the status of system services.

systemctl status nginx
systemctl restart docker

🔧 Use Case: Manage and troubleshoot services like Nginx, Docker, and others.

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8. netstat / ss – Network Ports & Connections

Check network connections, open ports, and listening services.

ss -tuln

🔧 Use Case: Verify whether your application is listening on the correct port.

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9. tail – View Log Files

Display the last few lines of a file. -f keeps the output live as the file grows.

tail -f /var/log/nginx/access.log

🔧 Use Case: Real-time log monitoring during deployments or debugging.

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10. crontab – Automate Scheduled Tasks

Use crontab to view or edit scheduled jobs.

crontab -e

🔧 Use Case: Schedule backups, health checks, or automated scripts.

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🧠 Bonus Tips for DevOps Engineers

• Use alias to shorten repetitive commands.

• Combine commands with &&, ||, and pipes | to build powerful one-liners.

• Learn to use vi or nano to edit config files directly on servers.

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✨ Conclusion

Mastering these 10 Linux commands is a must for every DevOps engineer. They form the foundation of server management, automation scripts, and cloud infrastructure operations. Whether you're SSHing into EC2 instances or debugging a Kubernetes node, these commands will always have your back.