What is Linux? History & Distributions

Linux for DevOps Engineers

Published: December 2025 | For: DevOps Beginners

Linux is the foundation of modern DevOps and cloud computing. Whether you're deploying applications, managing servers, or working with containers, Linux skills are essential. This guide covers what you actually need to know as a DevOps engineer, not everything about Linux.

Why Linux is Essential for DevOps

Understanding why Linux matters helps you prioritize what to learn. Linux isn't just another operating system - it's the backbone of cloud infrastructure.

Cloud Infrastructure

Over 90% of public cloud workloads run on Linux. AWS, Google Cloud, and Azure all use Linux extensively for their virtual machines and container services. When you work with cloud platforms, you're almost always working with Linux servers.

Container Technology

Docker containers and Kubernetes orchestration are built on Linux kernel features. Containers share the host system's kernel, which is why Docker originally only worked on Linux. Understanding Linux helps you troubleshoot container issues effectively.

Automation and Scripting

Linux provides excellent support for automation through bash scripting and command-line tools. Most DevOps automation tools like Ansible, Terraform, and CI/CD pipelines are designed to work seamlessly with Linux environments.

Cost and Flexibility

Linux is free and open-source, which means no licensing costs for servers. This makes it ideal for scaling infrastructure. The open-source nature also allows deep customization for specific needs.

Choosing the Right Linux Distribution

There are hundreds of Linux distributions, but for DevOps, you only need to know a few. Your choice depends on whether you're setting up servers or using Linux on your local machine.

For Production Servers

Ubuntu Server is the most popular choice for its excellent documentation, large community, and regular updates. It's user-friendly and widely supported.

CentOS/Rocky Linux/AlmaLinux are enterprise-focused distributions known for stability and long-term support. Many corporate environments use these.

Amazon Linux is optimized for AWS and comes pre-configured with useful tools for cloud deployment.

For Development Workstation

Ubuntu Desktop is perfect for beginners. It has a graphical interface but also gives you access to the full command-line power.

WSL2 (Windows Subsystem for Linux) allows you to run Linux directly on Windows 10/11. It's excellent for developers who need to work on Windows but use Linux tools.

macOS Terminal while not Linux, has similar Unix commands. Many DevOps tools work well on Mac.

Recommendation for Beginners

If you're starting out, install Ubuntu 22.04 LTS (Long Term Support) on a virtual machine or use WSL2 on Windows. Ubuntu has the largest community and best documentation for beginners. Once comfortable, you can explore other distributions.

Essential Linux Commands for DevOps

These are the commands you'll use daily in DevOps work. Focus on understanding what they do rather than memorizing every option.

File and Directory Operations

Working with files is fundamental. These commands help you navigate, create, and manage files and directories.

$ ls -la
# Lists all files with details including hidden files

$ cd /path/to/directory
# Changes current working directory

$ cp source destination
# Copies files or directories

$ rm -rf directory_name
# Removes files and directories (use with caution)

System Monitoring and Information

Monitoring system resources is crucial for troubleshooting performance issues and understanding system status.

$ top
# Shows running processes and resource usage in real-time

$ df -h
# Displays disk space usage in human-readable format

$ free -h
# Shows memory usage information

$ ps aux
# Lists all running processes with details

Networking Commands

Network troubleshooting is common in DevOps. These commands help diagnose connectivity issues.

$ ping google.com
# Tests network connectivity to a host

$ curl http://example.com
# Transfers data from a URL, useful for API testing

$ ssh username@server-ip
# Connects to a remote server securely

$ netstat -tulpn
# Displays network connections and listening ports

Permission and Process Management

Understanding permissions and process management is essential for security and troubleshooting.

$ sudo command
# Runs a command with superuser privileges

$ chmod 755 filename
# Changes file permissions (read, write, execute)

$ kill process_id
# Terminates a running process

$ systemctl status service_name
# Checks the status of a system service

Key Linux Concepts for DevOps

Linux File System Structure

Understanding the standard Linux directory structure helps you know where to find files and where to place your applications.

• /home - Contains user home directories. Your personal files go here.
• /etc - System configuration files. Application configurations are often stored here.
• /var - Variable files like logs, databases, and emails.
• /tmp - Temporary files that are deleted on reboot.
• /opt - Optional application software packages.
• /usr - User programs and data (different from /home).

This organization is standardized across most Linux distributions, making it easier to work on different systems.

Package Management

Package managers handle software installation, updates, and removal. Different distributions use different package managers.

For Ubuntu/Debian systems (apt):

$ sudo apt update
# Updates the list of available packages

$ sudo apt install package_name
# Installs a new package

$ sudo apt upgrade
# Upgrades all installed packages

For CentOS/RHEL systems (yum/dnf):

$ sudo yum update
# Updates all packages (older CentOS)

$ sudo dnf install package_name
# Installs package (newer Fedora/RHEL)

System Services with systemd

Modern Linux distributions use systemd to manage services (like web servers, databases). Understanding systemd is crucial for DevOps.

$ sudo systemctl start nginx
# Starts the Nginx web server

$ sudo systemctl stop nginx
# Stops the Nginx web server

$ sudo systemctl restart nginx
# Restarts the Nginx web server

$ sudo systemctl enable nginx
# Enables Nginx to start automatically on boot

$ sudo systemctl status nginx
# Shows the current status of Nginx

These commands work for any service (mysql, docker, apache, etc.) once you know the service name.

Users, Groups, and Permissions

Linux is a multi-user system. Understanding permissions is essential for security and collaboration.

$ sudo adduser newusername
# Creates a new user account

$ sudo usermod -aG groupname username
# Adds a user to a group

$ ls -la
# Shows file permissions in detail

File permissions are shown as 10 characters (like -rwxr-xr-x). The first character indicates file type, next three are owner permissions, next three are group permissions, and last three are others' permissions. r=read, w=write, x=execute.

Practical Learning Path

Here's a structured approach to learning Linux for DevOps:

1. First Two Weeks: Master basic navigation and file operations. Practice daily with commands like ls, cd, cp, mv, rm, cat, and grep.
2. Week 3-4: Learn text editing with nano or vim. Understand file permissions and user management.
3. Week 5-6: Practice package management and service control. Install and configure a web server like Nginx.
4. Week 7-8: Learn basic bash scripting. Start with simple automation tasks like backup scripts.
5. Week 9-10: Focus on networking - SSH, SFTP, firewall basics, and network troubleshooting.
6. Week 11-12: Practice log analysis and process monitoring. Learn to use tools like journalctl and htop.

Consistency is more important than intensity. Practice 30 minutes daily rather than 5 hours once a week.

Where You'll Use Linux in DevOps Work

Real-World Applications

Understanding where Linux fits in the DevOps workflow helps you see the practical importance of these skills.

• Cloud Servers: When you create virtual machines on AWS EC2, Google Cloud, or Azure, you're typically deploying Linux instances. Knowing Linux helps you configure and troubleshoot these servers.
• Container Environments: Docker containers are built from Linux base images. Even if your application runs on a different OS, the container runtime environment is Linux-based.
• CI/CD Pipelines: Jenkins servers, GitLab runners, and other CI/CD tools usually run on Linux. Your build scripts and deployment commands will execute in Linux environments.
• Infrastructure as Code: Tools like Terraform and Ansible often target Linux servers for configuration management and provisioning.
• Monitoring and Logging: Prometheus, Grafana, ELK Stack - these monitoring tools are typically deployed on Linux servers.

Focus on What Matters Most

You don't need to become a Linux expert overnight. Focus on these core areas that provide the most value for DevOps work:

1. Navigating the file system - Knowing where to find logs, configurations, and applications
2. Installing and updating software - Using package managers effectively
3. Managing services - Starting, stopping, and monitoring applications
4. Viewing and analyzing logs - Troubleshooting issues through log files
5. Basic shell scripting - Automating repetitive tasks
6. Network troubleshooting - Diagnosing connectivity problems

These skills cover about 80% of what you'll actually use in daily DevOps work.

Getting Hands-On Practice

Practice Environments

You need actual practice, not just reading. Here are practical ways to get hands-on with Linux:

• Google Cloud Shell: Free browser-based Linux terminal with 5GB persistent storage. No installation needed.
• Docker Containers: Run `docker run -it ubuntu bash` to get a clean Ubuntu container to practice in.
• Cloud VPS: Sign up for a $5/month virtual private server from DigitalOcean, Linode, or Vultr. This gives you real server experience.
• Virtual Machine: Install VirtualBox (free) and create an Ubuntu virtual machine on your computer.
• WSL2: If you use Windows, install Windows Subsystem for Linux 2 for a native Linux experience.

Practical Projects to Build Skills

Work through these projects to build practical Linux skills:

1. Set up a web server (Nginx or Apache) and serve a simple HTML page
2. Create a bash script that backs up a directory and emails you when done
3. Configure SSH keys for password-less login to a server
4. Install and configure a database (MySQL or PostgreSQL)
5. Set up a cron job to run a script daily
6. Monitor system resources and set up alerts for high usage

Each project will teach you multiple concepts and commands in context, which is more effective than isolated practice.

Final Advice for DevOps Engineers

Every senior DevOps engineer started as a Linux beginner. The key is consistent practice. Start with basic commands, understand the file system structure, and gradually build up to more complex tasks. Don't try to learn everything at once - focus on the skills that directly support your work in deployment, automation, and infrastructure management.

Remember that Linux is a tool, not the end goal. Your objective is to deploy and maintain applications reliably. Linux skills enable that objective. As you encounter real problems in your work, you'll naturally learn the specific Linux knowledge you need.