Learning Linux & Operating Systems 🖥️

📌 Why is Linux important in DevOps?

Linux is the foundation of most server systems, containers (Docker, Kubernetes), and cloud platforms. DevOps professionals need to master Linux to:

✅ Manage servers effectively.
✅ Write automation scripts.
✅ Handle files, users, and processes.
✅ Optimize systems and security.

⚙️ What is an Operating System?

An operating system (OS) is software that manages computer hardware and software resources, providing common services for programs. It acts as an intermediary between applications and hardware, handling tasks such as:

🔹 Memory management.
🔹 Process scheduling.
🔹 File system management.
🔹 Device control.

🌍 Popular operating systems:

💻 Personal computers: Windows, macOS, Linux (Ubuntu, Fedora,…)
📱 Mobile devices: iOS, Android
🖥️ Servers: Ubuntu Server, Red Hat Enterprise Linux, Windows Server

Each operating system has different characteristics, interfaces, and compatibility capabilities. They play crucial roles in system security, performance optimization, and providing consistent user experiences.

🛠️ Basic Linux Commands

Here are some important Linux commands:

🔍 System Information

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uname -a   # Display operating system information
uptime     # System uptime
free -m    # Check RAM memory

📂 File & Directory Management

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ls -l        # List files with detailed information
mkdir mydir  # Create new directory
rm -rf mydir # Delete directory and its contents

🚀 Process Management

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top         # Display running processes
ps aux      # List all processes
kill -9 PID # Stop process by PID

👤 User Management

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whoami               # View current user
sudo useradd devops  # Create new user
sudo passwd devops   # Set password for user

📜 Bash Script for System Resource Monitoring

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#!/bin/bash

echo "==== System Information ===="
uname -a

echo "==== System Uptime ===="
uptime

echo "==== RAM Memory ===="
free -m

▶️ How to run the script:

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chmod +x system_check.sh  # Grant execute permission to script
./system_check.sh         # Run script in terminal

📚 Learning Resources

Here are some free resources to learn more about operating systems:

🎯 Conclusion

✅ Linux is a mandatory skill in DevOps.
✅ Learn to use terminal & Bash scripting.

👉 Next step: Learn more about terminal and CLI usage to work effectively with systems.