Master Linux Troubleshooting: Hands-On Training for 2026 Pro (Udemy.com)

Master Linux administration, troubleshooting, shell scripting, security, networking, storage management, and real-world enterprise Linux skills through practical hands-on labs.

This course is designed to help students, system administrators, DevOps engineers, cloud professionals, and IT beginners build strong practical Linux skills from the ground up.

My name is Shikhar, and I’ll be your instructor throughout this journey into the world of Linux, system administration, troubleshooting, automation, shell scripting, networking, security, and enterprise-level server management.

In this course, you will learn Linux from the ground up with a strong focus on practical implementation, hands-on labs, and real-world industry scenarios.

Introduction to Linux: Basic Concepts and History of Unix/Linux

· Course Module Overview

· Understanding Unix: A Brief Introduction

· The Evolution of Linux: A Historical Perspective

Understanding Linux Filesystem & OS Installation

· Exploring the Linux Filesystem

· Understanding File Types in Linux

· Essential Downloads: RHEL, CentOS & Virtualization Tools

· Installing Linux on a Virtual Machine

· Connecting to Linux Using PuTTY

CentOS 10 Installation on Oracle VirtualBox – Complete Guide

· An Overview of This Section

· Download and Install VirtualBox

· Download CentOS 10 ISO

· Create a New Virtual Machine

· Configure the Virtual Machine

· Configure Virtual Hardware

· Hard Disk File Type and Format

· Uncheck - Proceed with Unattended Installation

· Begin the Installation

· Configure Installation Summary

· Log in to the CentOS Desktop Environment

· Access Linux VM from Windows using MobaXterm

· Login Issue Troubleshooting

Step-by-Step Guide to Installing CentOS 9 on Oracle VirtualBox

· Overview of Steps to Install CentOS 9 on Oracle VM

· Download and Install VirtualBox

· Download CentOS 9 ISO

· Create a New Virtual Machine

· Configure the Virtual Machine

· Start the Installation

· Install MobaXterm and PuTTY to access the virtual machines

· Access the virtual machine using MobaXterm and PuTTY

Linux Commands Tutorials

· In-depth lectures on essential Linux commands, demonstrated with real-time examples in a live environment.

· Overview of the Linux file system structure to understand directory hierarchy and navigation.

· Practical usage and explanations of commonly used commands, including:

pwd, cd, ls, less, cp, file, mkdir, more, mv, cat, rm, rmdir, wc, dd, head, tail, touch, ln, and more.

Understanding the Linux Filesystem Hierarchy

· What You Will Learn in This Section

· Linux Filesystem Explained

· Understanding Disk-Based Filesystems

· Memory-Based (tmpfs) Filesystem

· Understanding the Root ( / ) Filesystem in Linux

· Understanding devtmpfs Filesystem in Linux

· Understanding tmpfs Shared Memory Filesystem in Linux

· Understanding tmpfs Mounted on /run

· tmpfs Filesystem for systemd-journald Service

· Understanding the /boot Filesystem in Linux

· Understanding /run/user tmpfs Filesystem

Bash Profile, Variables, and Standard I/O Redirection

· Understanding the User's Home Directory

· Overview of .bash_profile, .bashrc, and .bash_logout

· Setting and Modifying the PATH Variable in .bash_profile

· Introduction to Bash Variables

· Environment and System Variables Explained

· Distinguishing Between Bash, Environment, and System Variables

· Practice Lab: Working with Different Types of Variables

· Understanding Standard Input, Output, and Error Streams

· Redirecting Input and Output Using >, 2>, &>, and More

· Lab: Practical Exercises on Variable Use and I/O Redirection

Linux User Administration: Best Practices

· Overview of User Administration

· Different User Account Types

· User Administration Files

· User Account Creation

· Configuring a User Account with Custom Attributes

· Linux User Groups: Primary vs. Secondary

· Usermod - Managing User Accounts

· Modifying User Account Groups in Linux

· Modify a User's Home Dorectory in Linux

· Modify a User's Shell in Linux

· Set Accout Expiration Date

· Overview of Shadow File

· Structure of the Shadow File

Managing User Password Expiration with the Chage Command

· Overview of Chage Command

· Set Minimum Password Age with Chage

· Set Maximum Password Age with Chage

· Set Password Warning Period with Chage

· Set Password Inactivity Period with Chage

· Set Account Expiration with Chage

· Configure Global Password Aging Policies

· Troubleshooting user and Group Issues in Linux

Permissions in Linux

· Understanding Basic File Permissions

· User, Group, and Others: Permission Categories

· Types of Permissions: Read, Write, Execute

· Changing Permissions and Ownership

· Special Permissions in Linux

· Setuid, Setgid, Sticky Bit, and ACL Explained

· Lab 1: Real-World File Permission Tasks

· Lab 2: Advanced Permission Scenarios from Industry

Managing File Access with ACLs (Access Control Lists)

· Introduction to ACL Concepts

· Setting ACLs on Files

· Understanding and Configuring Default ACLs

· Lab: Apply ACLs to Files

· Lab: Apply ACLs to Directories

· Lab: Using Mask to Restrict Permissions

· Lab: Working with Default ACLs

· Practice Exercise: Scenario-Based Task on ACLs

Managing sudo Access with visudo

· Basics of sudo and privilege management

· Using aliases in the sudoers file

· Understanding and editing the sudoers configuration

· Common sudo command examples

· Practice Lab: Set up and test sudo access

Linux Crontab

· Overview of Linux Crontab & its format

· Schedule a job for a specific period of time

· Schedule a job for more than one instance (e.g. twice a day)

· Schedule a job for a specific range of time

· Schedule a job every weekday during working hours

· how to view crontab entries?

· Schedule a job for every minute using cron

Linux Find Commands

· Basic find commands for finding files with names

· Find files based on their permissions

· Search files based on owners & groups

· Find files and directories based on date & time

· Find files and directories based on size

OpenSSH: Concepts and Hands-on Labs on CentOS 10