Series 2, Day 1: Understanding the Linux File System Hierarchy for RHCSA

Day 1

Hi everyone, your friend the Cloud Whistler is back! Continuing the Cloud Engineering Journey series, we’re diving into Series 2, focusing on RHCSA complete learning. Whether you’re aiming to pass the exam or just looking to expand your knowledge, this journey will be packed with fun, unique, and genuine insights. Today, we kick off with the Linux File System Hierarchy. Let’s make this exciting and easy to understand by comparing it to what many of us know from the Windows environment.

Index

1. Introduction to Linux File System Hierarchy

2. The Root Directory and Its Significance

3. Essential Directories and Their Uses

4. Understanding Bash

5. Basic Linux Commands

6. Summary

7. What's Next: Day 2 - Navigating the Linux File System

1. Introduction to Linux File System Hierarchy

In Linux, everything is represented as a file, including hardware and programs. These files are stored in directories, creating a tree-like structure known as the File System Hierarchy (FSH). Unlike Windows, which uses multiple drives (C:, D:, etc.), Linux uses a single rooted, inverted tree structure with the root directory (/) at the top. Think of it as a well-organized digital library where every book (file) has its place.

2. The Root Directory and Its Significance

The root directory, represented by a forward slash (/), is the starting point of the FSH. Imagine it as the "C:\" drive in Windows but for the entire Linux system. From here, all other directories branch out.

3. Essential Directories and Their Uses

/root - Home Directory for the Root User

This is the superuser's home directory, similar to the Administrator folder in Windows. It contains the root user’s personal files and configuration settings.

/bin - User Binaries

Contains essential binary executables for all users. Think of it as the "Program Files" for core command-line utilities like ps, ls, ping, grep, and cp.

/sbin - System Binaries

Houses binary executables used by the system administrator for system maintenance tasks, akin to Windows’ administrative tools. Examples include iptables, reboot, fdisk, ifconfig, and swapon.

/dev - Device Files

Contains files representing hardware devices, similar to Device Manager in Windows. Examples include /dev/tty1 for terminal devices and /dev/usbmon0 for USB devices.

/var - Variable Files

Stores variable data like log files, comparable to the "C:\Windows\Logs" directory. Subdirectories include:

- /var/log: System log files.

- /var/lib: Databases and package files.

- /var/mail: Emails.

- /var/tmp: Temporary files needed for reboot.

/mnt - Mount Directory

Used to temporarily mount filesystems. It’s like using a virtual drive in Windows to access additional storage.

/media - Removable Media Devices

Holds subdirectories where removable media like CDs and USB drives are mounted, similar to how Windows assigns drive letters to these devices.

/usr - User Binaries

Contains applications and files for user operations, similar to "C:\Program Files". It’s where user-installed software resides.

/etc - Configuration Files

Holds system configuration files, akin to the "Control Panel" and "System32\Config" in Windows. This directory controls the behavior of the operating system and applications.

/boot - Boot Loader Files

Contains files needed to boot the system, such as the GRUB boot loader and Linux kernels. Think of it as the "boot.ini" or "BCD" in Windows.

/opt - Optional Applications

Used for installing third-party software not included in the Linux distribution, similar to "C:\Program Files (x86)" for third-party apps. For instance, Google Earth would reside here.

/home - Home Directory

Contains user-specific directories, like "C:\Users". Each user’s personal files and configurations are stored here. For example, /home/bob for the user "bob".

/tmp - Temporary Files

Holds temporary files created by the system and users, akin to the "Temp" folder in Windows. Files here are deleted upon reboot.

/proc - Process Information

A pseudo-filesystem containing information about running processes, similar to the Task Manager in Windows. For instance, /proc/{pid} contains details about a specific process.

4. Understanding Bash

Bash (Bourne Again Shell) is the default command-line interface in Linux, providing a way to interact with the operating system through commands. It’s like Command Prompt or PowerShell in Windows but more powerful and versatile.

5. Basic Linux Commands

Here are some basic Linux commands to get you started:

- pwd: Shows the present working directory.

- ls: Lists files and directories in the current directory.

- uname -r: Displays the kernel version.

- cd: Changes the directory.

- clear: Clears the terminal screen.

- whoami: Displays the current logged-in username.

- history: Shows a list of previously used commands.

- date: Displays the current date and time.

Summary

Today, we’ve covered the fundamentals of the Linux File System Hierarchy, crucial for anyone preparing for the RHCSA exam or looking to deepen their Linux knowledge. We’ve explored the various directories, their purposes, and some basic commands to get you started.

What's Next: Day 2 - Navigating the Linux File System

Stay tuned for our next article where we’ll dive deeper into navigating the Linux file system like a pro. We’ll simplify concepts and provide practical examples to ensure you’re well-prepared for your RHCSA journey.

I hope you found this article helpful and engaging. There are no screenshots included in the Day 1 article, but there will be as I continue with the Part 2 edition for the Linux Series #CloudEngineeringJourney. If you have any questions or need further clarification, feel free to reach out. Happy learning!