If you’re a DevOps engineer, Linux is your playground. From managing servers to debugging containers, the command line is where most of the action happens. While there are hundreds of Linux commands, a handful of them form the backbone of daily DevOps tasks.

Here’s a curated list of the Top 20 Linux commands every DevOps engineer should master, along with why they matter and examples.

1. pwd – Print Working Directory

Quickly shows where you are in the filesystem.

pwd
# Output: /home/ubuntu

🔹 Useful for navigating large infrastructure scripts or container directories.

2. ls – List Files

Displays files and directories with details.

ls -l
ls -la

🔹 Helps inspect deployment directories, logs, or mounted volumes.

3. cd – Change Directory

Move around the filesystem.

cd /var/log

🔹 Essential when exploring logs or configuration folders.

4. cat – View File Contents

Quickly dump file content to the terminal.

cat /etc/os-release

🔹 Handy for checking configs without opening an editor.

5. less – Scroll Through Files

View long files with scroll/navigation support.

less /var/log/syslog

🔹 Great for investigating server or CI/CD pipeline logs.

6. tail – Stream Logs

View the last lines of a file; -f follows changes.

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

🔹 Critical for live log monitoring in production.

7. head – View File Start

Shows the first few lines of a file.

head -n 20 /etc/passwd

🔹 Useful for checking headers of config/data files.

8. grep – Search Text

Search patterns inside files or streams.

grep "ERROR" /var/log/syslog

🔹 Used daily for debugging logs or scanning configs.

9. find – Search Files

Locate files by name, type, or time.

find /var/www -name "*.log"

🔹 Saves time when tracking down config or log files.

10. chmod & chown – Permissions

Change file permissions and ownership.

chmod 644 config.yaml
chown ubuntu:ubuntu config.yaml

🔹 Critical for fixing permission issues in deployments.

11. df – Disk Usage

Check available disk space.

df -h

🔹 Helps prevent outages caused by full disks.

12. du – Directory Size

Measure size of files/directories.

du -sh /var/log/*

🔹 Great for tracking large log files eating up storage.

13. ps – Process Status

Check running processes.

ps aux | grep nginx

🔹 Useful for debugging stuck services or containers.

14. top / htop – Resource Usage

Monitor CPU, memory, and process usage.

top

🔹 Vital for identifying high-resource processes during incidents.

15. kill – Terminate Processes

Stop processes by PID.

kill -9 12345

🔹 Important for quickly killing hung or runaway processes.

16. systemctl – Service Control

Manage systemd services.

systemctl status nginx
systemctl restart docker

🔹 Core to managing production services.

17. journalctl – View Service Logs

Inspect logs from systemd-managed services.

journalctl -u nginx --since "10 min ago"

🔹 Easier than digging into log files manually.

18. scp – Secure Copy

Copy files between local and remote servers.

scp file.txt user@server:/home/user/

🔹 Everyday DevOps need for moving configs, scripts, or backups.

19. ssh – Remote Access

Log in to remote servers.

ssh ubuntu@server-ip

🔹 The lifeline for DevOps engineers working on cloud instances.

20. tar & gzip – File Archiving

Compress and extract files.

tar -czvf backup.tar.gz /etc/nginx/
tar -xzvf backup.tar.gz

🔹 Essential for backups, deployments, and moving code artifacts.

Bonus Commands

• wget / curl → Download files or test APIs.

Final Thoughts

Mastering Linux commands is non-negotiable for DevOps engineers. These 20 commands are the Swiss Army knife of daily operations — whether you’re managing cloud servers, troubleshooting Kubernetes nodes, or debugging pipelines.

👉 Pro tip: build your own .bashrc or .zshrc with aliases for these commands to save time and reduce typos.