By Muhammad Usman Khan, Lead Cloud Instructor at Sherdil E-Learning

Published: 21 Oct 2026  |  Last updated: 21 Oct 2026

Launch your first server on AWS, Azure, or Google Cloud, and you will not see a desktop. You get a black terminal and a blinking cursor. That is why Linux is the first thing cloud and DevOps interviews check, usually before anyone asks about certifications.

This guide explains why Linux matters for cloud work, three free ways to practise, the 25 commands you will type almost every day (grouped by task, with real server examples), and a 30-day plan to make them stick. For a full, structured course taught in Urdu, our Linux Administrator Essentials course goes from installation to shell scripting across 227 lessons.

Why cloud and DevOps jobs expect Linux

The default server images on AWS EC2, such as Amazon Linux and Ubuntu, are Linux. Docker containers are built on Linux, Kubernetes clusters mostly run on Linux nodes, and the machines that run CI/CD pipelines usually do too. No matter which cloud you choose, you end up typing commands into a Linux shell.

Interviews reflect this. Expect questions like "the server's disk is full, what do you check?" or "the web service will not start, where do you look?" Both are answered with the commands in this guide. Our DevOps career roadmap puts Linux in months 1 and 2 for the same reason, and the Docker tutorial assumes you are already comfortable at the command line.

Three free ways to practise

Option	Best for	How to start
Virtual machine on your laptop	Learning safely, breaking things without worry	Install VirtualBox or VMware, then Ubuntu Server inside it
WSL on Windows	Quick practice without a second machine	Open PowerShell as administrator and run wsl --install
A small cloud server	Real cloud experience	Launch an Ubuntu instance on the AWS Free plan and connect over SSH

For the cloud option, set up your account safely first using our AWS Free Tier account guide for Pakistan. On EC2, the default username is ubuntu for Ubuntu images and ec2-user for Amazon Linux.

Which distribution? Start with Ubuntu Server LTS (24.04 or 26.04). Avoid CentOS Linux for new learning: CentOS Linux 7 reached end of life on 30 June 2024 and no longer gets security updates. If your target employer uses Red Hat systems, practise on Rocky Linux or AlmaLinux later; the commands below work on both families, except the package manager.

The 25 commands, grouped by task

Learn them in this order. Each group builds on the one before, and together they cover most of what a junior cloud or DevOps engineer does on a server.

1. Finding your way around (4 commands)

Command	What it does	Real example
pwd	Shows the folder you are in	pwd → /home/ubuntu
ls	Lists files; -l adds details, -a shows hidden files, -h makes sizes readable	ls -lah /var/log
cd	Moves between folders	cd /etc/nginx, then cd ~ to go home, cd - to go back
find	Searches for files by name, age, or size	find /var/log -name "*.log" -mtime -1 (logs changed in the last day)

2. Working with files and folders (5 commands)

Command	What it does	Real example
mkdir	Creates folders; -p creates the whole path	mkdir -p ~/projects/app/logs
cp	Copies files; -r copies folders	cp -r ~/projects/app ~/backup/app-$(date +%F)
mv	Moves or renames	mv app.conf app.conf.old
rm	Deletes; -r deletes folders	rm -r old-folder (there is no recycle bin, so check the path first)
tar	Bundles and compresses files	tar -czf backup.tar.gz ~/projects/app, and tar -xzf backup.tar.gz to extract

3. Reading logs and searching text (4 commands)

Command	What it does	Real example
cat	Prints a whole file	cat /etc/os-release (which Linux is this?)
less	Opens long files you can scroll; press q to quit	less /var/log/syslog
tail	Shows the end of a file; -f follows it live	tail -f /var/log/nginx/access.log
grep	Finds lines that match a word or pattern	grep -i "error" /var/log/syslog

You will also need one text editor. Start with nano because its shortcuts are printed on screen, then learn the basics of vim since it is installed on almost every server.

4. Users and permissions (4 commands)

Command	What it does	Real example
sudo	Runs one command as administrator	sudo apt update
adduser	Creates a user with a home folder	sudo adduser deploy
chmod	Changes who can read, write, or run a file	chmod 400 my-key.pem (SSH refuses keys that others can read)
chown	Changes the owner of files	sudo chown -R www-data:www-data /var/www/html

5. Checking server health (4 commands)

Command	What it does	Real example
df	Shows disk space per drive	df -h (first check when "disk full" errors appear)
free	Shows memory use	free -h
top	Live view of running processes and CPU; q to quit	top
ps	Lists processes once, good for searching	ps aux | grep nginx

6. Software, services and remote access (4 commands)

Command	What it does	Real example
apt	Installs and updates software on Ubuntu and Debian	sudo apt update && sudo apt install nginx
systemctl	Starts, stops, and checks services	sudo systemctl status nginx, then restart or enable
ssh	Logs in to a remote server	ssh -i my-key.pem ubuntu@<server-ip>
scp	Copies files to or from a server over SSH	scp -i my-key.pem site.zip ubuntu@<server-ip>:/home/ubuntu/

On Red Hat family systems such as Rocky Linux and Amazon Linux 2023, the package manager is dnf instead of apt. Everything else in these tables works the same way.

Put it together: a 20-minute mini lab

This short exercise uses most of the 25 commands on a real cloud server:

1. Launch a small Ubuntu instance on your AWS Free tier account and allow HTTP (port 80) in its security group.
2. On your laptop, protect the key with chmod 400 my-key.pem, then connect with ssh -i my-key.pem ubuntu@<server-ip>.
3. Run cat /etc/os-release, df -h and free -h to see what you are working with.
4. Install a web server: sudo apt update && sudo apt install -y nginx, then check it with sudo systemctl status nginx.
5. Open the server's public IP in your browser. You should see the Nginx welcome page.
6. Back in the terminal, run sudo tail -f /var/log/nginx/access.log and refresh the browser. Each visit appears as a new line.
7. Press Ctrl+C, log out, and terminate the instance from the EC2 console so it stops using your credits.

A 30-day practice plan

Thirty minutes a day is enough. Type every command yourself rather than copying it.

Week	Focus	Finish the week able to
1	Groups 1 and 2: navigation and files	Create, copy, move, archive, and delete a project folder without looking anything up
2	Group 3 plus nano and vim basics	Find every error in a log file and edit a config file safely
3	Group 4 plus SSH keys	Create a user, give it the right permissions, and log in as it over SSH with a key
4	Groups 5 and 6 plus a first shell script	Install and troubleshoot a service, and write a script that backs up a folder with tar

Mistakes that slow beginners down

• Working as root all day. Use a normal user and add sudo only for commands that need it. One wrong command as root can damage the whole system.
• Fixing permission errors with chmod 777. It lets anyone read and change the file. Work out which user needs access and give only that.
• Pasting commands without reading them. Be especially careful with anything that includes sudo, rm -rf or a script downloaded from the internet.
• Learning on CentOS Linux in 2026. It is end-of-life. Ubuntu Server LTS, Rocky Linux or AlmaLinux will match what employers run today.
• Memorising instead of practising. You do not need every flag in your head. Learn to check man ls or ls --help and keep practising on a real machine.

Frequently asked questions

Which Linux should I learn first for cloud computing?

Ubuntu Server LTS. It is free, widely used on AWS, Azure, and Google Cloud, and has the most beginner material. Learn Rocky Linux or AlmaLinux later if your employer uses Red Hat systems.

Do I need Linux for AWS or Azure certifications?

Entry-level exams such as AWS Cloud Practitioner do not test Linux commands. Associate-level labs and real cloud jobs assume you can work comfortably on a Linux server.

How long does it take to learn Linux basics?

With 30 minutes of practice a day, most beginners are comfortable with these 25 commands in four to six weeks. Full system administration takes a few months.

Can I learn Linux on a Windows laptop?

Yes. Windows Subsystem for Linux (WSL) runs Ubuntu inside Windows, or you can install Ubuntu in a free virtual machine.

Is the Linux Administrator Essentials course for complete beginners?

Yes. It starts from the basics, needs no previous Linux experience, and is taught entirely in Urdu.

Start with Linux, then build up

Linux is step one for almost every cloud path: DevOps, cloud security, architecture, or support. Once these commands feel natural, Docker, Kubernetes, and Terraform become far easier to learn, and so does cloud security.