linux

📌 Introduction

If you are starting your journey in Linux, DevOps, or Cloud Computing, Linux commands are not optional — they are mandatory.

Most production servers run on Linux, and as a DevOps engineer, you’ll interact with servers daily for:

Deployment
Monitoring
Debugging
Automation

In this post, I’m sharing a structured Linux commands cheat sheet (basic + advanced) with clear explanations and real examples, especially useful for beginners and DevOps learners.

👋 If you found this article helpful and want to follow my DevOps learning journey,
connect with me on LinkedIn 👉 RamuChelloju

🧱 1. Basic Linux Commands

These commands are used every day on any Linux system.

🔹 List files and directories

ls
ls -l
ls -a

🔹 Change directory

cd /var/log
cd ..

🔹 Show current path

pwd

🔹 Create and remove directories

mkdir app
rmdir app

🔹 Copy and move files

cp file1 file2
cp -r dir1 dir2
mv oldname newname

🔹 Create empty file

touch test.txt

📂 2. File Operations

Used to read, search, compress, and manage files.

🔹 View file content

cat file.txt
less largefile.log

🔹 Search inside files

grep "error" app.log

🔹 Archive and compress

tar -cvf backup.tar folder/
zip files.zip file1 file2
unzip files.zip

🔹 Change permissions and ownership

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

⚙️ 3. Process & System Monitoring

Helps you understand what is running on the server.

🔹 View running processes

ps aux

🔹 Live system usage

top
htop

🔹 Run process after logout

nohup python app.py &

🔹 Process tree

pstree

🔹 View system logs

journalctl
journalctl -u nginx

💽 4. Disk & Memory Commands

Used heavily during production issues.

🔹 Disk usage

df -h
du -sh /var/log

🔹 Memory usage

free -h

🔹 Block devices

lsblk

🔹 Mount and unmount

mount /dev/xvdf /data
umount /data

🔹 Sync files

rsync -av source/ destination/

🌐 5. Networking Commands

Used for server access and debugging.

🔹 Check connectivity

ping google.com

🔹 Test APIs and URLs

curl https://example.com

🔹 Download files

wget https://example.com/file.zip

🔹 Connect to remote server

ssh -i key.pem user@server_ip

🔹 Copy files between servers

scp file.txt user@server:/path

🔐 6. Permissions & Ownership (Very Important)

Most Linux issues happen due to wrong permissions.

🔹 File permissions

chmod 644 file.txt
chmod 755 script.sh

🔹 Change owner

chown ec2-user:ec2-user file.txt

🔹 Sudo access

sudo command

🔹 Edit sudoers safely

visudo

🚀 How DevOps Engineers Use These Commands

As a DevOps engineer, you’ll use Linux commands to:

Debug production issues
Check server health
Deploy applications
Automate tasks using shell scripts
Manage cloud servers (AWS EC2, GCP, Azure)

👉 Strong Linux basics = Strong DevOps career

🧠 Learning Tips for Beginners

Practice daily (don’t just read)
Break things and fix them
Focus on understanding, not memorizing
Combine Linux with Git, Docker, and Cloud

✅ Conclusion

Linux commands are the foundation for DevOps, Cloud, and SRE roles.
Once you master these basics, learning tools like Docker, Kubernetes, Jenkins, and Terraform becomes much easier.

If you are a beginner — start slow, stay consistent, and practice daily.

Command Palette