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Linux Logical Volume Manager Tutorial

In this series of video tutorials, you will learn what LVM is and when you should use it. You’ll discover how LVM creates and uses layers of abstraction between storage devices and file systems including Physical Volumes, Volume Groups, and Logical Volumes.

More importantly, you’ll learn how to configure LVM, starting with the pvcreate command to configure physical volumes, the vgcreate command to configure volume groups, and the lvcreate command to create logical volumes.

Plus, you’ll see how easy it is to extend file systems and logical volumes using the lvextend command. Likewise, adding more space to the storage pool is painless with the vgextend command.

Next, you’ll learn how to create mirrored logical volumes and even how to migrate data from one storage device to another, without taking any downtime.

Introduction to the Logical Volume Manager (LVM)

Layers of Abstraction in LVM

Creating Physical Volumes (PVs), Volume Groups (VGs), and Logical Volumes (LVs)

Extending Volume Groups and Logical Volumes

Mirroring Logical Volumes

Removing Logical Volumes, Physical Volumes, and Volume Groups

Migrating Data from One Storage Device to Another

Logical Volume Manager – Summary

More Linux System Administration Resources

If you enjoyed this tutorial, then you’ll definitely enjoy our Linux courses available here: https://courses.linuxtrainingacademy.com/

LVM Companion Workbook

How to Find Any File or Command on a Linux System

In this video you’ll learn how to:

Find a command that is not in your PATH.
Find any file on a Linux system.
Use the following commands: find, locate, type, which, grep, touch, updatedb, sudo, and ls.

Linux tar Command Tutorial

In this video you will learn:

How to create, extract and compress an archive.
The difference between .tar, tar.gz, and .tgz files.
How to use gzip and gunzip.
The difference between “tar cvf” and “tar -cvf” (notice the hyphen…)
Some bonus command line tips to speed up working with tar (and any other type of) files.

A Definitive Guide to Linux Man Pages

Do you want to know where to find the answer to just about any Linux question you may ever have? Well…

All the answers are in the built-in man pages on a Linux system!

That’s probably not what you wanted to hear. 🙁

When you’re trying to figure something out or have a Linux question it can be annoying to get a reply like this:

“Just read the man page!”

It’s actually good advice, but it has one fatal flaw: ~~It assumes you know how to read a man page.~~ Scratch that. It assumes you know how to understand and use what you read in a man page.

When you first start looking at man pages they might appear to contain a bunch of random punctuation. You might wonder…

Why are some things enclosed in brackets and others aren’t?
Why are there three little periods after some things?
Why do some options have one dash and others have two?

To get the answers to all those questions and more, watch the video on this page. It will have you reading man pages like an old pro. You’ll finally understand all those man page hieroglyphics and you’ll never feel lost again. 😉

You’ll learn…

How to search through man pages to find the help (or command) you’re looking for.
How to decipher all the man page conventions such as underlined words, options enclosed in brackets, and more.
What to do when man doesn’t work. (IE, the “other” man command.)
How to mix and match multiple options (and option types) to make the command do exactly what you want.
And more…

If you’ve ever seen anything in a man page that you didn’t understand, this will definitely help you out.

Installing an SSL Certificate on CentOS Running Apache

See below to download the step-by-step instructions for this tutorial. It includes all the commands and everything you see in the video.

Introduction to Installing an SSL Certificate on CentOS 7

In this video lesson, you’re going to learn how to install a valid SSL certificate on a CentOS Linux Server running the Apache web server. By the way, the SSL certificate you’ll install will be issued by Let’s Encrypt entirely for free. Traditionally, you’ve had to pay for SSL certificates and renew them every year. With Let’s Encrypt that’s all changed.

SSL Certificate Installation Steps Overview

In this tutorial, you will learn how to install an SSL Certificate issued by Let’s Encrypt on a CentOS Linux system running the Apache web server. You will start out by installing Apache with mod_ssl. From there, you’ll add firewall rules to allow HTTP and HTTPS traffic. Next, you’ll enable the EPEL repository by installing the epel-release package. That will enable you to install the Certbot application and the Apache Certbot plugin. You will then create and install an SSL certificate using the Certbot utility. Finally, you’ll automate the certificate renewal process so that your site is never without a valid SSL certificate.

Why Install an SSL Certificate? (Do I Need an SSL Certificate?)

Before you start configuring your Linux server, I want to give you some important background information. As a quick reminder, SSL stands for Secure Sockets Layer and it allows for encrypted communications between a user’s web browser and a web server.

It’s important to use SSL any time sensitive data is involved such as credit card numbers, personal information, and authentication credentials such as passwords. Even if your web server is not handling sensitive information, using SSL can enhance the trust of your visitors to your site. Some web browsers now warn users that the site is “not secure” if it’s not using SSL.

Also, search engines such as Google, rank SSL enabled web sites hiring in search results, so there is an SEO or Search Engine Optimization, benefit as well.

Prerequisites and Information Needed for an SSL Certificate

By the way, this video makes a couple of assumptions. The first one is that your Linux system is running CentOS or RedHat Enterprise Linux. The second one is that your system is accessible over the public Internet. The last assumption is that your server has a valid DNS entry that points to your Linux system. For example, if your domain is www.example.com, when someone types in that domain in the web browser, they are actually connecting to your Linux server. I’ve included some additional information about the DNS configuration in the project documentation.

NOTE: This tutorial demonstrates the installation of an SSL certificate for the demo.linuxtrainingacademy.com domain. Even though this domain will be used throughout this tutorial, you must use your own domain when following along.

Download the Step-by-Step Instructions

How to Configure MySQL Master-Slave Replication on Ubuntu Linux

Master Server Configuration

Install MySQL Server:

sudo apt-get install -y mysql-server

Add the following to /etc/mysql/my.conf:

bind-address = 10.11.12.101
server-id = 1
log_bin = /var/log/mysql/mysql-bin.log

Restart MySQL:

sudo service mysql restart

Create a replication user:

mysql -u root
CREATE USER 'repl'@'%' IDENTIFIED BY 'slavepassword';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
exit

Create a snapshot and copy it to the slave server:

mysqldump -u root --all-databases --master-data > masterdump.sql
scp masterdump.sql 10.11.12.102:

Slave Server Configuration

On the slave, install MySQL Server:

sudo apt-get install -y mysql-server

Add the following to /etc/mysql/my.conf:

bind-address = 10.11.12.102
server-id = 2

Restart MySQL:

sudo service mysql restart

Tell the slave what user, password, and host to use for the master server:

mysql -u root
CHANGE MASTER TO
MASTER_HOST='10.11.12.101',
MASTER_USER='repl',
MASTER_PASSWORD='slavepassword';
exit

Restore the snapshot:

mysql -uroot < masterdump.sql

Start the slave:

mysql -u root
start slave;
show slave status\G;

Taking it to the next level… (Multimaster Clustering)

If you want to learn how to create a true multi-master MySQL database cluster, check out High Availability for the LAMP Stack.