Ultimate Linux Training 2025: Master Troubleshooting Skills

Ultimate Linux Training 2025: Master Troubleshooting Skills udemy course

Learn Linux with a hands-on, project-based approach. 42+ hours, 450+ lectures to boost your skills and career growth.

By the End of This Course, You Will Be Able To:

• Confidently use the Linux operating system to boost your productivity and support your career growth.

• Perform everyday computing tasks effectively using the Linux command line.

What Will You Learn from This Module?

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

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.

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

· Overview of OpenSSH

· What Are Some Of The OpenSSH Features?

· OpenSSH options are controlled through the sshd_config file

· Lab Session

Telnet

· Overview about telnet

· Configuration of telnet server on Linux

· Xinetd Service

Process Management

· Understanding ps commands with custom properties & Nice values etc

· Different stats of a process like "D", "S", "T", "Z" etc

· Kill commands to terminate the process

· Lab

Kernel Modules

· What is Kernel & its features

· Kernel Modules

· Commands to manipulate the kernel (insmod,lsmod,modinfo,modprobe &rmmod)

· How to know the name of the module or kernel driver for any device like lan

· Lab

Disk Partitions, File Systems Creations & RAID Configuration

· Creating the partitions in a simple disk using fdisk

· Understanding the different options in fdisk utility

· Creating File Sytems using (ext3/ext4/xfs FS)

· Mounting/Umounting FS

· Entry in fstab

· Introduction to RAID

· Concepts & features of RAID

· RAID Level

· How to configure the different levels of Raids like (0,1,5,6, 10, etc.)

· Lab Sessions

Logical Volume Manager Administration

· LVM Architecture Overview

· LVM Components

· LVM Logical Volumes

· Logical Volume Creation Overview

· Growing a File System on a Logical Volume

· Logical Volume Backup

· LVM Administration with CLI Commands

· Using CLI Commands

· Physical Volume Administration

· Creating Physical Volumes

· Displaying Physical Volumes

· Preventing Allocation on a Physical Volume

· Resizing a Physical Volume

· Removing Physical Volumes

· Volume Group Administration

· Creating Volume Groups

· Adding Physical Volumes to a Volume Group

· Displaying Volume Groups

· Removing Physical Volumes from a Volume Group

· Changing the Parameters of a Volume Group

· Activating and Deactivating Volume Groups

· Removing Volume Groups

· Overview of LVM Metadata

· Metadata Contents

· How to identify and recover failed LVM disk

RPM (Red Hat Package Manager)

· Install: It is used to install any RPM package.

· Remove: It is used to erase, remove or un-install any RPM package.

· Upgrade: It is used to update the existing RPM package.

· Verify: It is used to query about different RPM packages.

· Query: It is used for the verification of an RPM package.

YUM (Yellowdog Updater, Modified)

· Overview of YUM

· Configuration& and installation of yum on Red Hat Linux Server

· Lab-1

· Lab-2

· Yum History Command

· Reverting and Repeating Transactions like undo & redo using yum command

Linux OS Minor Upgrade

· Linux OS upgrade from RHEL 7.1 to RHEL 7.2

· Lab Practice Sessions

File Transfer Protocol

· Overview of FTP Server

· Installation and configuration of FTP Server

· Lab-1

· Lab-2

Apache Web Server Administration

· Basic Setup

· Verify installation

· Package files

· Main configuration file(s)

· Backup

· Edit the httpd.conf configuration file

· ServerRoot

· PidFile

· ServerName

· Add site to the host's file

· DocumentRoot

· ErrorLog

· Listen

· Create your HTML documents

· Start the Web Server

· Access the website

· Local access

· Internal & external access

· Summary of basic setup

DNS (Domain Name System)

· Overview of DNS

· Understanding root & top-level domains

· How DNS works practically

· What happens when I type any website name in the address bar of the browser

Samba Server

· Overview of Samba Server

· Features of Samba Server

· How Samba Server Works

· Samba File sharing Server

· CIFS File System

· Practice Lab Sessions

Postfix Mail Server Configuration

· The structure of the Email System

1.1 Mail User Agent

1.2 Mail Transfer Agent

1.3 Mail Delivery Agent

1.4 SMTP

· Configuring an RHEL Email System

· Postfix Pre-Installation Steps

· Installing Postfix on RHEL 7

· Configuring Postfix

· Starting Postfix on an RHEL System

· Configure a Null Client

· Relayhost

· Introduction Dovecot, Imap & pop3

· Configuring Dovecot

· Thunderbird - Mail User Agent (Configure Mail Box)

Securing & hardening a Linux System

· Linux Physical Security

· How to break root password

· Securing the grub menu

· Reset root password from rescue mode

· BIOS Protection

· General Security

· Keep your system updated

· Turn off IPv6

· Disable USB Stick to detect

· Restrict Users to Use Old Passwords

· Check Password Expiration of a User

· Password Expiration - Lab Session

· Verify accounts for an empty password

· Verify accounts with "Zero" UID

· Review logs regularly

· Keep /boot as read-only

Managing Server Firewalls

· Firewall concepts

· About nftables, features, and advantages of firewalld

· Firewalld components, pre-defined zones

· How packet flows through the firewall

· Check firewalld services - Lab Session

· Adding and Removing Services & Port from Firewall Server - Lab Session

· Add Services Permanently in Firewalld - Lab Session

· Add HTTP Service in firewalld - Lab Session

· Port forwarding - Lab Session

· Conceptual discussion about Masquerading, Packet Flow in Firewalld

· Masquerading with Port Forwarding - Lab Session

· About Rich Rules in Firewalld

· Specifically allow a Server using Rich Rules - Lab Session

· Allow Telnet Port, SSH with log-prefix using Rich Rule - Lab Session

· Accept, Reject, Drop - Lab Session

Network File System (NFS) on Linux

· Overview of NFS Server

· Installation and configuration of NFS Server

· Lab-1

· Lab-2

Automating Installation using Kickstart

· Overview of Kickstart Server

· Features of Kickstart Server

· Configuration & Installation of Kickstart Server

· Configuration of dhcp, tftpd, nfs for Kickstart Server

· Configuration of kickstart config file using graphical mode

· PXE Boot Environment

· Lab Session

· Unattended Client boot and do the installation via network

Networking Concepts in Linux

· New Sets of commands introduced in RHEL 7 for managing the network interfaces.

· Check the status of ethernet interfaces

· Add and configure the new ethernet interface

· Activate the network services

· Commands to change the network properties of an existing interface

· Delete the ethernet interface

· Learning various new commands related to managing network interfaces.

· Overview of Routing Table

· Understanding the output of netstat -rn or route -n output

· Lab

Linux Performance Monitoring

· Introduction about Performance monitoring in Linux

· Important four subsystems that need to be monitored.

1. CPU
2. Memory
3. IO
4. Network

· Familiar & understanding with CPU Utilization

· Like Context switches, Run Queue, CPU utilization & Load Average

· Familiar & understanding with Memory Utilization

· Familiar & understanding with I/O Analyses

· Familiar & understanding with Network Monitoring

· Familiar with various Commands to manage performance issues in Linux Servers

· top

· vmstat

Managing SELinux Security

· Introduction - SELinux

· SELinux Security Concepts

· Changing SELinux Modes

· Practice Lab Sessions

· Changing SELinux Contexts

· SELinux Booleans

· Audit logs & troubleshooting SELinux

Backup and Restore

· Overview of Backup

· Various commands for backup

· Types of backup

· Full backup, Incremental backup, and differential backup

dump command to take backup & restoration

Advanced Linux Commands

· dig, nslookup, rsync, scp, ssh, sftp, find, grep, locate, df, du, lsof, ps, top, who,cut, sort, vi, sed, awk, tar, gzip, bzip2 etc

· useradd, userdel, usermod, groupadd, groupdel, id, chage, chroot, chown etc

· mount, umount, fdisk, mkfs, fsck,/proc, uptime etc

· ping, nslookup, telnet, ifconfig, ifconfig-a, netstat -a etc

· systemctl -at service, systemctl -t service --state=active, systemctl start name.service, systemctl enable name.service etc

· pvs, vgs, pvdisplay,lvs, lvdisplay, pvcreate, pvremove, vgcreate, vgrename, vgremove, vgextend, vgreduce, lvcreate, lvextend, lvreduce,fdisk, vgexport, vgimport, vgcfgrestore, vgcfgbakcup, watch, whoami, passwd, su etc.

Linux Bash Shell Scripting: A Practical way of Learning

Introduction of Shell Programming

· What is Bash Shell?

· Types of Shell available in Linux

· About Shell Scripting

· Bash Shell Startup Scripts

· User’s Home Directory - .bash_profile, .bashrc & .bash_logout

· Shebang

· Create a simple Shell Script

· Setting up permissions on a script

· Debug a Script

The Shell Variables & Environment

· Bash Variables

· Environmental Variables

· System Variables

· Assign values to shell variables

· Customize the bash shell environments

· set, env & export command

· Rules for naming the variable name

· Simple Script using the echo command

· Quoting

· There are three Type of quoting

· The double quote

· The single quote

· The Backslash

· User's Input via Keyboard

· Read Command

· IFS

· Practice Lab Session

Arithmetic Operations

· Performing Arithmetic Operations

· Create an integer Variable

· Create the Constants Variable

· Path name expansion

· Wildcards [*], ?, [..] etc

· Create & use aliases

· Practice Lab Sessions

Industrial Project to Completely Automate the Pre-validation report

· A Shell Script to collect the required information from a server

· The Bash Color

· Writing Color Text

· Various Color Codes for Foreground & Background Text

· Lab Session on Bash Color

· Script to fetch the system information i.e system_details

· Schedule the script via cron

· Final Script to fetch the environment report with a single click

· Lab Session

Conditional Statements (Decision Making)

· Overview of conditional execution

· What is Condition?

· Boolean value (True & False)

· If else statement

· Lab Session on if..else..

· if..elif..else..fi statement

· test command

· Logical AND &&

· Logical OR !!

· The exit status of a command

· Numeric Comparison

· String Comparison

· File Attributes Comparison

· Shell Command line parameters

· Positional parameters via special shell variable

· Practice Lab Session

Bash Loops

· Overview of loop statement

· for loop statement

· Lab on for loop

· for loop using C like Syntax

· for loop using command-line arguments

· Nested for loop statement

· Chessboard using a nested loop statement

· While loop statement

· Lab Session - read a text file line-by-line or using IFS

· infinite while loop

· case statement

· Lab session on case statement

· Create a simple menu-driven program or automation tool Using Case Statement

· Industrial Project

· Discussed various scripts using for or while loop

Shell Redirection & Process Management

· Input Output Redirection in Linux

· Lab Session on redirection

· Pipelines in Linux

· tee command

· file descriptor (fd) to file for output

· file descriptor (fd) to file for input

· file descriptor (fd) for reading & writing

· Practice Lab Session

· Overview of a Process

· Foreground & background Process

· Various Stats of a process

· Lab Session

Functions

· Defining functions

· Displaying functions

· Nested functions

· Lab Session - writing functions

· Calling functions

· Local & global variables

· Passing arguments into a function

· return statement

· Practice Lab Sessions

AWK

· Introduction Awk

· Pattern matching

· User-defined variables in awk

· Awk pre-processing

· Awk post-processing

· Practice Lab Session

SED Stream Editor

· Introduction

· Replacing or substituting string.

· Replacing the nth occurrence of a pattern in a line

· Replacing all the occurrence of the pattern in a line

· Changing the slash (/) delimiter

· Using & as the matched string

· Duplicating the replaced line with /p flag

· Replacing string on a specific line number

· Replacing string on a range of lines

· Replace on lines which match a pattern

· Deleting lines

· Add a line after a match

· Add a line before a match

· Last Lecture