Mastering Linux Administration: Take your sysadmin skills to the next level by configuring and maintaining Linux systems

Mastering Linux Administration

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This is to everyone who did not believe in me, and to everyone who believed in me.

To my mother and father, my twin sister, my beloved Uca, and my truthful friends.

In memory of my late grandfather, Miron, who would have loved to see this new book finished before he passed away.

Contributors

About the author

Alexandru Calcatinge is an open-minded architect with a background in computer science and mathematics. He is a senior university lecturer with a PhD in urban planning from Ion Mincu University of Architecture and Urban Planning and a postgraduate degree in DevOps from Caltech’s Center for Technology and Management Education (CTME). He teaches students about architectural programming and development and open source technologies. He has authored five books on architecture and urban planning and numerous scientific articles on urban and rural development. Alex was certified as a Linux trainer in 2017. He loves the DevOps philosophy and the possibilities that cloud technologies bring for the future. He is also a certified programming analyst, computer network administrator, trainer, designer, and life coach.

I want to thank the people who have been close to me and supported me unconditionally, especially my parents, my twin sister, and my friends. I want to express my deepest gratitude to my one and only Uca for sticking by my side during a time of turmoil, and for her constant support and trust in me.

Julian Balog is a senior software engineer with more than 15 years of experience in the industry. Currently, his work primarily focuses on application delivery controllers, containerized workflows, networking, and security. With a never-ending passion for Linux and open-source technologies, Julian is always in pursuit of learning new things while solving problems and making things work through simple, efficient, and practical engineering. He lives with his wife, two children, and an Aussie-doodle in the greater Seattle area, Washington.

The authors would like to thank the wonderful editorial and production team at Packt for their professional leadership, dedication, and guidance throughout the writing of this book. We are indebted to them for many helpful suggestions and the comprehensive revision of the drafts. We are also grateful to the reviewers for their critical comments. We could not have hoped for a better team and support.

About the reviewers

Himanshu Sharma has nearly 18 years of experience in designing, architecting, and developing cloud and network software. He previously worked for some of the biggest companies such as Brocade and Juniper and start-ups such as Netskope. Currently, he is working with Netskope as a Principal Engineer, responsible for Netskope’s security service offering. He designed, architected, and developed Netskope’s advanced threat protection services from the ground up. He has a keen interest and experience in developing scalable cloud services with cutting-edge technologies. His favorite hobbies are skiing and playing video games.

I would like to thank my wife, Puja, who gave me all her support, and my two loving and beautiful daughters, Navya and Jaanvi.

Also, I want to thank my brother, Sudhanshu, for always having my back, and my parents for all their sacrifices to get me where I am today.

Dennis Salamanca is a passionate technology enthusiast with a solid track record of over 12 years in the IT industry. Throughout his career, he has had the privilege of working with renowned industry leaders such as Amazon, VMware, Microsoft, and Hewlett-Packard Enterprise. His dedication to continuous learning is reflected in an extensive collection of over 15 technical certifications spanning various domains including cloud, storage, Linux, Kubernetes, and virtualization. Notably, he is actively involved in the development team for Linux+ and Cloud+ certifications and proudly contributes as a member of the esteemed CompTIA Linux and Cloud Subject Matter Experts and Technical Advisory Committee.

I would like to acknowledge my wife and family for all their support over these years. Without their motivation and support, nothing would’ve been possible.

Table of Contents

Preface

Part 1: Basic Linux Administration

1

Installing Linux

Technical requirements

Introducing the Linux operating system

Exploring Linux distributions

Choosing a Linux distribution

Installing Linux – the basics

How to install Linux on bare metal

Linux in a VM

VM provisioning using Hyper-V

VM provisioning using Oracle’s VirtualBox

Enabling Windows Subsystem for Linux

Installing Linux – the advanced stages

The Linux boot process

PXE network boot explained

Linux distributions – a practical guide

Case study – development workstation

Case study – secure web server

Use case – personal blog

Use case – media server

Summary

Questions

Further reading

2

The Linux Shell and Filesystem

Technical requirements

Introducing the Linux shell

Establishing the shell connection

The command-line prompt

Shell command types

Explaining the command structure

Consulting the manual

The Linux filesystem

Directory structure

Working with files and directories

Understanding file paths

Basic file operations

Commands for file viewing

Commands for file properties

Using text editors to create and edit files

Using Vim to edit text files

The nano text editor

Summary

Questions

Further reading

3

Linux Software Management

Technical requirements

Linux software package types

The DEB and RPM package types

The snap and flatpak package types

Managing software packages

Managing DEB packages

Managing RPM packages

Using the snap and flatpak packages

Installing new desktop environments in Linux

Installing KDE Plasma on Fedora Linux

Summary

Questions

Further reading

4

Managing Users and Groups

Technical requirements

Managing users

Understanding sudo

Creating, modifying, and deleting users

Managing groups

Creating, modifying, and deleting groups

Managing permissions

File and directory permissions

Summary

Questions

Further reading

5

Working with Processes, Daemons, and Signals

Technical requirements

Introducing processes

Understanding process types

The anatomy of a process

Working with processes

Using the ps command

Using the pstree command

Using the top command

Using the kill and killall commands

Using the pgrep and pkill commands

Working with daemons

Working with systemd daemons

Explaining inter-process communication

Working with signals

Summary

Questions

Further reading

Part 2: Advanced Linux Administration

6

Working with Disks and Filesystems

Technical requirements

Understanding devices in Linux

Linux abstraction layers

Device files and naming conventions

Understanding filesystem types in Linux

Understanding disks and partitions

Common disk types

Partitioning disks

Introducing LVM in Linux

LVM snapshots

Summary

Questions

Further reading

7

Networking with Linux

Technical requirements

Exploring basic networking

Computer networks

The OSI model

The TCP/IP network stack model

TCP/IP protocols

IP addresses

Sockets and ports

Linux network configuration

Working with network services

DHCP servers

DNS servers

Authentication servers

File sharing

Printer servers

File transfer

Mail servers

NTP servers

Remote access

Understanding network security

Summary

Questions

Further reading

8

Linux Shell Scripting

Technical requirements

Exploring the Linux shell

Bash shell features

Bash shell variables

Basics of shell scripting

Creating a shell script file

Variables in shell scripts

Using mathematical expressions in shell scripts

Using programming structures

Using arrays in Bash

Reading input data

Formatting output data

Understanding exit statuses and testing structures

Using conditional if statements

Using looping statements

Working with functions

Using sed and (g)awk commands

Using scripts to showcase interprocess communication

Shared storage

Unnamed pipes

Named pipes

Sockets

Scripting for administrative tasks

Creating scripts for system administrative tasks

Packaging scripts

Summary

Questions

Further reading

9

Securing Linux

Technical requirements

Understanding Linux security

Introducing SELinux

Working with SELinux

Introducing AppArmor

Working with AppArmor

Final considerations

Working with firewalls

Understanding the firewall chain

Introducing Netfilter

Working with iptables

Introducing nftables

Using firewall managers

Summary

Exercises

Further reading

10

Disaster Recovery, Diagnostics, and Troubleshooting

Technical requirements

Planning for disaster recovery

A brief introduction to risk management

Risk calculation

Designing a DRP

Backing up and restoring the system

Disk cloning solutions

Introducing common Linux diagnostic tools for troubleshooting

Tools for troubleshooting boot issues

Tools for troubleshooting general system issues

Tools for troubleshooting network issues

Tools for troubleshooting hardware issues

Summary

Questions

Further reading

Part 3: Server Administration

11

Working with Virtual Machines

Technical requirements

Introduction to virtualization on Linux

Efficiency in resource usage

Introduction to hypervisors

Understanding Linux KVMs

Choosing the hypervisor

Using the KVM hypervisor

Working with basic KVM commands

Creating a VM using the command line

Basic VM management

Advanced KVM management

Connecting to a VM

Cloning VMs

Creating VM templates

Obtaining VM and host resource information

Managing VM resource usage

Provisioning VMs using cloud-init

Understanding how cloud-init works

Installing and configuring cloud-init

Public key authentication with SSH

Summary

Exercises

Further reading

12

Managing Containers with Docker

Technical requirements

Understanding Linux containers

Comparing containers and VMs

Understanding the underlying container technology

Understanding Docker

Working with Docker

Which Docker version to choose?

Installing Docker

Using some Docker commands

Managing Docker containers

Working with Dockerfiles

Building container images from Dockerfiles

Deploying a containerized application with Docker

Deploying a website using Docker

Summary

Questions

Further reading

13

Configuring Linux Servers

Technical requirements

Introducing Linux services

Setting up SSH

Installing and configuring OpenSSH on Ubuntu

Setting up a DNS server

Caching a DNS service

Creating a primary DNS server

Setting up a secondary DNS server

Setting up a DHCP server

Setting up an NFS server

Installing and configuring the NFS server

Configuring the NFS client

Testing the NFS setup

Setting up a Samba file server

Installing and configuring Samba

Creating Samba users

Accessing the Samba shares

Summary

Questions

Further reading

Part 4: Cloud Administration

14

Short Introduction to Cloud Computing

Technical requirements

Introduction to cloud technologies

Exploring the cloud computing standards

Understanding the architecture of the cloud

Knowing the key features of cloud computing

Introducing IaaS solutions

Amazon EC2

Microsoft Azure Virtual Machines

Other strong IaaS offerings

Introducing PaaS solutions

Amazon Elastic Beanstalk

Google App Engine

DigitalOcean App Platform

Open source PaaS solutions

Introducing CaaS solutions

Introducing the Kubernetes container orchestration solution

Deploying containers in the cloud

Introducing microservices

Introducing DevOps

Exploring cloud management tools

Ansible

Puppet

Chef Infra

Summary

Further reading

15

Deploying to the Cloud with AWS and Azure

Technical requirements

Working with AWS EC2

Introducing and creating AWS EC2 instances

Introducing AWS EC2 placement groups

Using AWS EC2 instances

Working with the AWS CLI

Working with Microsoft Azure

Creating and deploying a virtual machine

Connecting with SSH to a virtual machine

Managing virtual machines

Working with the Azure CLI

Summary

Questions

Further reading

16

Deploying Applications with Kubernetes

Technical requirements

Introducing Kubernetes

Understanding the Kubernetes architecture

Introducing the Kubernetes object model

The anatomy of a Kubernetes cluster

Installing and configuring Kubernetes

Installing Kubernetes on a desktop

Installing Kubernetes on VMs

Working with Kubernetes

Using kubectl

Deploying applications

Running Kubernetes in the cloud

Summary

Questions

Further reading

17

Infrastructure and Automation with Ansible

Technical requirements

Introducing Ansible architecture and configuration management

Understanding the Ansible architecture

Introducing configuration management

Installing Ansible

Installing Ansible on Ubuntu

Installing Ansible using pip

Working with Ansible

Setting up the lab environment

Configuring Ansible

Using Ansible ad hoc commands

Exploring Ansible modules

Using Ansible playbooks

Using templates with Jinja2

Creating Ansible roles

Summary

Questions

Further reading

Index

Other Books You May Enjoy

Preface

Mastering Linux Administration provides the ultimate coverage of modern server and cloud administration technologies.

Technology evolves at an unprecedented speed, and Linux and related technologies are at the forefront of innovation. This makes it really hard to keep up and learn new things. Present Linux administrators need to know about more than just Linux, thus containerization and cloud technologies are essential for the future DevOps expert.

Linux is the operating system that powers almost everything, from IoT to personal computers to servers, and is the foundation for all cloud technologies. It enables you to master the cloud through the power of the command line.

You will begin by learning about the command line, working with files, processes, users, packages, and filesystems, then you will begin administering network services and hardening security, and finally, you will learn about cloud computing, containers, and orchestration. You will learn how to work at the command line, learn about the most important Linux commands, and master users, processes, and services administration. You will also learn how to harden Linux security using iptables. At the end, you will work with containers, hypervisors, virtual machines, Ansible, and Kubernetes and learn how to deploy Linux on AWS and Azure. By the end of this book, you will have mastered Linux and you will be confident in working with Linux from bare metal to the cloud, in a pure DevOps fashion.

Who this book is for

This book is for Linux administrators who want to understand the fundamentals, as well as modern concepts of Linux system administration. Windows system administrators looking to extend their knowledge to the Linux OS will also benefit from this book.

What this book covers

Chapter 1, Installing Linux, shows you how to install Linux on physical hardware (bare-metal) and inside a virtual machine in Windows. As we are targeting future Linux system administrators, the command line will be used most of the time, with little reference to the GUI. The future Linux professional will learn how to install Linux and how the boot process works.

Chapter 2, The Linux Shell and Filesystem, teaches you how to use the command line and introduces you to the most widely used commands in Linux. You will learn about the structure of a basic command, how the Linux filesystem is organized, the structure of the Linux operating system, and the structure of a file. By the end of the chapter, you will also know how to use VI/VIM, one of the widely used command-line text editors in Linux.

Chapter 3, Linux Software Management, explains how to use specific software management commands, how software packages work depending on the distribution of choice, and how to build your own packages.

Chapter 4, Managing Users and Groups, shows you how to manage user accounts in Linux. This is one of the most important tasks a Linux system administrator should master. You will be introduced to the general concepts, the specific files for user administration, and how to manage accounts. By the end of the chapter, you will know how to work with permissions and how to change them, and you will understand the special permissions and attributes.

Chapter 5, Working with Processes, Daemons, and Signals, explores processes, signals, and services in Linux. You will learn how to manage them, how to use them, and what the differences are between them.

Chapter 6, Working with Disks and Filesystems, teaches you how to manage disks and filesystems, understand storage in Linux, use Logical Volume Management (LVM) systems, and how to mount and partition.

Chapter 7, Networking with Linux, discusses how networking works in Linux, including the key concepts and how to configure your network from the command line and GUI.

Chapter 8, Linux Shell Scripting, shows you how to create and use Bash shell scripts for task automation in Linux. This will prove an invaluable asset for any system administrator.

Chapter 9, Securing Linux, delves into advanced topics of Linux security. You will learn how to work with SELinux and AppArmor.

Chapter 10, Disaster Recovery, Diagnostics, and Troubleshooting, shows you how to do a system backup and restore in a disaster recovery scenario. Also, you will learn how to diagnose and troubleshoot a common array of problems.

Chapter 11, Working with Virtual Machines, describes how to set up and work with KVM virtual machines on Linux.

Chapter 12, Managing Containers with Docker, introduces containers and discusses how to use Docker-specific tools to deploy your applications.

Chapter 13, Configuring Linux Servers, shows you how to configure different types of Linux servers, from Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), Secure Shell (SSH), Samba file-sharing servers, and Network File System (NFS). This is one of the core foundations for any good Linux system administrator.

Chapter 14, Short Introduction to Computing, covers the basics of cloud computing. You will be presented with core technologies such as infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS), containers-as-a-service (CaaS), DevOps, and cloud management tools.

Chapter 15, Deploying to the Cloud with AWS and Azure, explains how to deploy Linux to AWS and Azure.

Chapter 16, Deploying Applications with Kubernetes, teaches you how to use Kubernetes to monitor and secure your deployments and how to manage your containers and networks. You will learn what Kubernetes is and how to use its diverse community approaches.

Chapter 17, Infrastructure and Automation with Ansible, introduces Ansible, including how to configure it, and how to manage playbooks, modules, and servers. At the end of this chapter, you will be a master of automation.

To get the most out of this book

You will need Ubuntu Linux LTS or Debian Linux to perform the examples in this book. No prior knowledge of Linux is necessary.

If you are using the digital version of this book, we advise you to type the code yourself or access the code from the book’s GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

Download the example code files

You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/Mastering-Linux-Administration-Second-Edition. If there’s an update to the code, it will be updated in the GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: To check the contents of a binary deb package, you can use the ar command.

A block of code is set as follows:

spec:

     replicas: 1

Any command-line input or output is written as follows:

$ sudo zypper search nmap

When we wish to draw your attention to a particular part of a code block or command, the relevant lines or items are set in bold:

uid=1004(alex2) gid=1100(admin)

groups=1100(admin),1200(developers),1300(devops),1400(managers)

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: Navigate to Virtual Machines, select your instance, and click Size under Availability + Scale.

Tips or important notes

Appear like this.

Get in touch

Feedback from our readers is always welcome.

General feedback: If you have questions about any aspect of this book, email us at [email protected] and mention the book title in the subject of your message.

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Part 1:Basic Linux Administration

In this first part, you will master the Linux command line and basic administrative tasks, such as managing users, packages, files, services, processes, signals, and disks.

This part has the following chapters:

Chapter 1, Installing Linux

Chapter 2, The Linux Shell and Filesystem

Chapter 3, Linux Software Management

Chapter 4, Managing Users and Groups

Chapter 5, Working with Processes, Daemons, and Signals

1

Installing Linux

Recent years have been marked by a significant rise in the adoption of Linux as the operating system of choice for both server and desktop computing platforms. From enterprise-grade servers and large-scale cloud infrastructures to individual workstations and small-factor home appliances, Linux has become an ever-present platform for a wide range of applications.

The prevalence of Linux, perhaps now more than ever, brings into the spotlight much-needed administration skills for a growing community of system administrators and developers. In this book, we take a practical approach to Linux administration essentials, with the modern-day system administrator, DevOps team member, and developer in mind.

In this second edition, we will adopt a slightly different approach to installing Linux. As this is a book meant for more advanced readers, we will no longer discuss the basic aspects of installing the operating system in such detail as in the first edition. The information has been updated to the most relevant aspects available as of the beginning of 2023 with regard to operating system versioning.

In this first chapter, we’ll guide you through the Linux installation process, either on physical hardware (bare metal) or using a Virtual Machine (VM).

Here are the topics we cover in this chapter:

Introducing the Linux operating system

Installing Linux – the basics

Enabling the Windows Subsystem for Linux

Installing Linux – the advanced stages

Linux distributions – a practical guide

Technical requirements

We will use the following platforms and technologies in this chapter:

Linux distributions: Ubuntu

VM hypervisors: Oracle VM VirtualBox, VMware Workstation Player, and Hyper-V

VM host platforms: Windows 11 (equally applicable on macOS)

Introducing the Linux operating system

Linux is a relatively modern operating system created in 1991 by Linus Torvalds, a Finnish computer science student from Helsinki. Originally released as a free and open source platform prohibiting commercial redistribution, Linux eventually adopted the GNU General Public Licensing (GPL) model in 1992. This move played a significant role in its wide adoption by the developer community and commercial enterprises alike. It is important to note that the Free Software Foundation community distinctly refers to Linux operating systems (or distributions) as GNU/Linux to emphasize the importance of GNU for free software.

Initially made for Intel x86 processor-based computer architectures, Linux has since been ported to a wide variety of platforms, becoming one of the most popular operating systems currently in use. The genesis of Linux could be considered the origin of an open source alternative to its mighty predecessor, Unix. This system was a commercial-grade operating system developed at the AT&T Bell Labs research center by Ken Thompson and Dennis Ritchie in 1969.

Exploring Linux distributions

A Linux operating system is typically referred to as a distribution. A Linux distribution, or distro, is the installation bundle (usually an ISO image) of an operating system that has a collection of tools, libraries, and additional software packages installed on top of the Linux kernel. A kernel is the core interface between a computer’s hardware and its processes, controlling the communication between the two and managing the underlying resources as efficiently as possible.

The software collection bundled with the Linux kernel typically consists of a bootloader, shell, package management system, graphical user interface, and various software utilities and applications.

The following diagram is a simplified illustration of a generic Linux distribution architecture:

Figure 1.1 – Simplified view of a generic Linux architecture

There are hundreds of Linux distributions currently available. Among the oldest and arguably most popular ones are Debian, Fedora, openSUSE, Arch Linux, and Slackware, with many other Linux distributions either based upon or derived from them. Some of these distros are divided into commercial and community-supported platforms.

Important note

As writing this second edition, CentOS became a rolling release and is the base from which future Red Hat Enterprise Linux (RHEL) versions are derived. Its place was taken by other free community distributions that use the RHEL binaries. Among those, Rocky Linux is a good example, and we will reference it throughout this book. One other community distribution based on RHEL is AlmaLinux.

One of the key differences among Linux distributions is the package management system they use and the related Linux package format. We’ll get into more detail on this topic in Chapter 3. For now, the focus is on choosing the right Linux distribution based on our needs. But before being able to decide, you should first know a little about some of the most widely used distributions. Therefore, in the next section, we will briefly present to you some Linux distros.

Common Linux distributions

This section summarizes the most popular and common Linux distributions at the time of writing this edition, with emphasis on their package manager type. Most of these distros are free and open source platforms. Their commercial-grade variations, if any, are noted:

Fedora, CentOS Stream and RHEL: CentOS and its derivatives use Red Hat Package Manager (RPM) as their package manager. CentOS Stream, now a rolling release distribution, is based on the open source Fedora project. It is suited to both servers and workstations. RHEL is a commercial-grade version derived from CentOS Stream, designed to be a stable platform with long-term support. The community distribution that uses RHEL binaries is Rocky Linux.

Debian: The package manager for Debian and most of its derivatives is Debian Package (DPKG). Debian is releasing at a much slower pace than other Linux distributions, such as Linux Mint or Ubuntu, for example, but it’s relatively more stable.

Ubuntu: Ubuntu uses Advanced Package Tool (APT) and DKPG as package managers. Ubuntu is one of the most popular Linux distributions, releasing every 6 months, with more stable Long Term Support (LTS) releases every other year.

Linux Mint: Linux Mint also uses APT as its package manager. Built on top of Ubuntu, Linux Mint is mostly suitable for desktop use, with a lower memory usage than Ubuntu (with the Cinnamon desktop environment, compared to Ubuntu’s GNOME). There’s also a version of Linux Mint built directly on top of Debian, called Linux Mint Debian Edition (LMDE).

openSUSE: openSUSE uses RPM, Yet another Setup Tool (YaST), and Zypper as package managers. openSUSE has two versions available: one is called Tumbleweed and is a rolling release, a leading-edge Linux distribution; the other is Leap, a regular release version, which uses the same code base as SUSE Linux Enterprise. Both versions are suited to desktop and server environments. SUSE Linux Enterprise Server is a commercial-grade platform. openSUSE was regarded as one of the most user-friendly desktop Linux distributions before the days of Ubuntu.

Important note

In this book, our focus is mainly on the Linux distributions that are widely used in both community and commercial deployments, such as Ubuntu, Fedora/Rocky Linux, and openSUSE. Most of the examples in this book are equally appliable to any Linux distro. We will specify which one we use for given examples or scenarios.

Now that you know a fair amount of information about the most common Linux distros, in the next section we will give you some hints on how to choose a Linux distribution.

Choosing a Linux distribution

There are many aspects involved in selecting a Linux distribution, based on various functional requirements. A comprehensive analysis would be far beyond the scope of this chapter. However, considering a few essential points may help with making the right decision:

Platform: The choice between a server, a desktop, or an embedded platform is probably one of the top decisions in selecting a Linux distribution. Linux server platforms and embedded systems are usually configured with the core operating system services and essential components required for specific applications (such as networking, HTTP, FTP, SSH, and email), mainly for performance and optimization considerations. On the other hand, Linux desktop workstations are loaded (or pre-loaded) with a relatively large number of software packages, including a graphical user interface for a more user-friendly experience. Some Linux distributions come with server and desktop flavors (such as Ubuntu, Fedora, and openSUSE), but most distros have a minimal operating system, with further configuration needed (such as Rocky Linux, and Debian). Usually, such distributions would be good candidates for Linux server platforms. There are also Linux distributions specifically designed for desktop use, such as elementary OS, Pop!_OS, or Deepin. For embedded systems, we have highly optimized Linux distros, such as Raspbian and OpenWRT, to accommodate small-form factor devices with limited hardware resources.

Infrastructure: Today we see a vast array of application and server platform deployments spanning from hardware and local (on-premises) data centers to hypervisors, containers, and cloud infrastructures. Weighing a Linux distribution against any of these types of deployments should take into consideration the resources and costs involved. For example, a multi-CPU, large-memory, and generally high-footprint Linux instance may cost more to run in the cloud or a Virtual Private Server (VPS) hosting infrastructure. Lightweight Linux distributions take fewer resources and are easier to scale in environments with containerized workloads and services (for instance, with Kubernetes and Docker). Most Linux distributions now have their cloud images available for all major public cloud providers (for instance, Amazon AWS, Microsoft Azure, and Google Compute Engine). Docker container images for various Linux distributions are available for download on Docker Hub (https://hub.docker.com). Some Docker images are larger (heavier) than others. For example, the Ubuntu Server Docker image outweighs the Alpine Linux Docker image considerably, and this may tip the balance when choosing one distribution over the other. Also, to address the relatively new shift to containerized workflows and services, some Linux distributions offer a streamlined or more optimized version of their operating system to support the underlying application infrastructure. For example, Fedora features the Fedora CoreOS (for containerized workflows) and Fedora IoT (for Internet of Things ecosystems).

Performance: Arguably, all Linux distributions can be tweaked to high-performance benchmarks in terms of CPU, GPU, memory, and storage. Performance should be considered very closely with the platform and the application of choice. An email backend won’t perform very well on a Raspberry Pi, while a media streaming server would do just fine (with some external storage attached). The configuration effort for tuning the performance should also be taken into consideration. Rocky Linux, Debian, openSUSE, Fedora and Ubuntu all come with server and desktop versions reasonably optimized for their use. The server versions can be easily customized for a particular application or service, by only limiting the software packages to those that are essential for the application. To further boost performance, some would go to the extent of recompiling a lightweight Linux distro (for instance, Gentoo) to benefit from compiler-level optimizations in the kernel for specific subsystems (for instance, the networking stack or user permissions). As with any other criteria, choosing a Linux distribution based on some application or platform performance is a balancing act, and most of the time, common Linux distros will perform exceptionally well.

Security: When considering security, we have to keep in mind that a system is only as secure as its weakest link. An insecure application or system component would put the entire system at risk. Therefore, the security of a Linux distribution should be scrutinized as it pertains to the related application and platform environment. We can talk about desktop security for a Linux distro serving as a desktop workstation, for example, with the user browsing the internet, downloading media, installing various software packages, and running different applications. The safe handling of all these operations (against malware, viruses, and intrusions) would make for a good indicator of how secure a system can be. There are Linux distros that are highly specialized in application security and isolation and are well suited for desktop use: Qubes OS, Kali Linux, Whonix, Tails, and Parrot Security OS. Some of these distributions have been developed for penetration testing and security research.

On the other hand, we may consider the server security aspect of Linux server distributions. In this case, regular operating system updates with the latest repositories, packages, and components would go a long way to securing the system. Removing unused network-facing services and configuring stricter firewall rules are further steps for reducing the possible attack surface. Most Linux distributions are well equipped with the required tools and services to accommodate this reconfiguration. Opting for a distro with frequent and stable upgrades or release cycles is generally the first prerequisite for a secure platform (for instance, Rocky Linux, RHEL, Ubuntu LTS, or SUSE Enterprise Linux).

Reliability: Linux distributions with aggressive release cycles and a relatively large amount of new code added in each release are usually less stable. For such distros, it’s essential to choose a stable version. Fedora, for example, has rapid releases, being one of the fastest-progressing Linux platforms. Yet, we should not heed the myths claiming that Fedora or other similar fast-evolving Linux distros, such as openSUSE Tumbleweed, are less reliable. Don’t forget, some of the most reliable Linux distributions out there, RHEL and SUSE Linux Enterprise (SLE), are derived from Fedora and openSUSE, respectively.

There’s no magic formula for deciding on a Linux distribution. In most cases, the choice of platform (be it server, desktop or IoT) combined with your own personal preferences is what determines the Linux distribution to go for. With production-grade environments, most of the previously enumerated criteria become critical, and the available options for our Linux platform of choice would be reduced to a few industry-proven solutions.

Important note

In this book, our focus is mainly on the Linux distributions that are widely used in both community and commercial deployments, such as Ubuntu, Fedora/Rocky Linux, and openSUSE. That said, most of the examples in this book are equally applicable to any Linux distro. We will specify which one we use for given examples or scenarios.

Now that you know a bit about what a Linux distribution is, along with the most commonly used ones and their use cases, in the following two sections we will present the basic and advanced aspects of Linux installation.

Installing Linux – the basics

This section serves as a quick guide for the basic installation of an arbitrary Linux distribution. For hands-on examples and specific guidelines, we use Ubuntu. We also take a brief look at different environments hosting a Linux installation. There is an emerging trend of hybrid cloud infrastructures, with a mix of on-premises data center and public cloud deployments, where a Linux host can either be a bare-metal system, a hypervisor, a VM, or a Docker container.

In most of these cases, the same principles apply when performing a Linux installation. For detail on Docker-containerized Linux deployments, see Chapter 13.

In the following sections, we will show you how to install Linux on bare metal and on a Windows 11 host using different VM hypervisors, and using WSL. Installing on a macOS host is basically the same as installing on Windows using a VM hypervisor, and we will not cover that.

How to install Linux on bare metal

This section describes the essential steps required for a Linux installation on bare metal. We use this term when referring to hardware such as laptops, desktops, workstations, and servers. In a nutshell, the main steps are downloading the ISO image, creating bootable media, trying out the live mode, and finally, doing the installation.

The steps used here are equally applicable to virtual machine installations, as you will see in the following sections.

Step 1 – Download

We start by downloading our Linux distribution of choice. Most distributions are typically available in ISO format on the distribution’s website. For example, we can download Ubuntu Desktop at https://ubuntu.com/download/desktop.

Using the ISO image, in the next step we can create the bootable media required for the Linux installation. We can also use the ISO image to install Linux in a VM, as shown in the next section.

Step 2 – Create the bootable media

As we install Linux on a PC desktop or workstation (bare-metal) system, the bootable Linux media is generally a CD/DVD or a USB device. With a DVD-writable optical drive at hand, we can simply burn a DVD with our Linux distribution ISO. But because modern-day computers, especially laptops, rarely come equipped with a CD or a DVD unit of any kind, the more common choice for bootable media is a USB drive.

Important note

There’s also a third possibility of using a Preboot eXecution Environment (PXE) boot server. PXE (pronounced pixie) is a client-server environment where a PXE-enabled client (PC/BIOS) loads and boots a software package over a local or wide area network from a PXE-enabled server. PXE eliminates the need for physical boot devices (CD/DVD, USB) and reduces the installation overhead, especially for a large number of clients and operating systems. Probing the depths of PXE internals is beyond the scope of this chapter, but we will give you a short introduction on how it works for Linux installations by the end of this chapter. A good starting point to learn more about PXE is https://en.wikipedia.org/wiki/Preboot_Execution_Environment.

A relatively straightforward way to produce a bootable USB drive with a Linux distribution of our choice is via using tools such a UNetbootin (https://unetbootin.github.io) or Balena Etcher (https://www.balena.io/etcher). Both UNetbootin and Etcher are cross-platform utilities, running on Windows, Linux, and macOS.

We will use Balena Etcher for this example of creating a bootable USB drive in Windows:

Figure 1.2 – Create a bootable USB drive with Balena Etcher

Here are the basic steps for creating a bootable USB drive with Ubuntu Desktop using Balena Etcher. We assume the Ubuntu Desktop ISO image has been downloaded and Etcher is installed (in our case on Windows 11):

Choose the ISO file with your Linux distribution of choice.

Select the USB target destination disk.

Flash the previously selected disk with the ISO of your choice.

The process should take a couple of minutes and the USB drive will be ready. Now, let’s look at how we can take the bootable media for a spin.

Step 3 – Try it out in live mode

This step is optional.

Most Linux distributions have their ISO image available for download as live media. We say most because not all of them offer this option, at least not by default. Nevertheless, among those who do offer live media by default are Ubuntu and Fedora.

Once we have the bootable media created with our Linux distribution of choice, we can run a live environment of our Linux platform without actually installing it. In other words, we can evaluate and test the Linux distribution before deciding whether we want to install it or not. The live Linux operating system is loaded in the system memory (RAM) of our PC, without using any disk storage. We should make sure the PC has enough RAM to accommodate the minimum required memory of our Linux distribution.

When booting the PC from a bootable media, we need to make sure the boot order in the BIOS is set to read our drive with the highest priority. On a Mac, we need to press the Option key immediately after the reboot start-up chime and select our USB drive to boot from. When on a PC, make sure you access your BIOS interface and select the appropriate device for boot. Depending on your system, you will either have to press one of the F2, F10, F12, or F1 keys after hitting Enter, or the Delete key, as a general rule. In some specific cases, there could be another Function key assigned for this. The keys that you need to press are usually specified at the bottom of the initial bootup screen.

Upon reboot, the first splash screen of our Linux distribution should give us the option of running in live mode, as seen in the following illustration for Ubuntu Desktop (Try Ubuntu):

Figure 1.3 – Choosing live mode for Ubuntu Desktop

Next, let’s take a look at the installation procedure of our Linux distro, using the bootable media.

Step 4 – Perform the installation

We start the installation of our Linux distribution by booting the PC from the bootable media created in step 2. To ensure the system can boot from our external device, we are sometimes required to change the boot order in the BIOS, especially if we boot from a USB drive. Do as specified in the previous paragraph to select the right boot drive.

In the following sections, we showcase the installation process of Ubuntu using its ISO images. We choose the Desktop and Server versions for Ubuntu and highlight the main differences between them. As a comparison, Rocky Linux and CentOS Stream come in a single flavor, in essence, a server platform with an optional graphical user interface. Similar to those, openSUSE offers one installation medium for both desktop and server installs. Fedora, on the other hand, has different installation mediums for desktop and server.

We will now walk you through the process of installing Linux inside a VM.

Linux in a VM

In each of the subsections in the Installing Linux section, we will also provide a brief guide on how to prepare a VM environment for the related Linux platform.

A VM is an isolated software abstraction of a physical machine. VMs are deployed on top of a hypervisor. A hypervisor provides the runtime provisioning and resource management of VMs. A couple of general-purpose hypervisors used are the following:

Oracle VM VirtualBox (https://www.virtualbox.org)

VMware Workstation (https://www.vmware.com/products/workstation-pro.html)

Hyper-V (available only in Windows Pro, Enterprise, or Education)

The first two of these hypervisors are cross-platform virtualization applications and run on both Intel and AMD processor architectures on Windows, macOS, and Linux. The latter is only available on Windows Pro, versions 10 and 11.

Important note

At the time of writing this book, hypervisors for the Apple silicon Macs are provided only by VMware Player and Parallels. Oracle VirtualBox is still in preview for the Advanced RISC Machines (ARM) architecture. Both solutions from VMware and Parallels are paid-for software on macOS, so you will need to purchase them in order to use them.

The difference between installing Linux on a VM compared to a physical machine is minor. The notable distinction is related to the VM sizing and configuration steps, making sure the minimum system requirements of the Linux distribution are met. Thus, in the following sections we will install Ubuntu on VMware Workstation under Windows.

Please take into account that installing Linux on VMware Player under macOS is very similar, and we will not duplicate the process in this edition of the book. macOS functionality was discussed in the first edition of the book, but given the limited availability of hypervisors for the Apple silicon platform, we have decided to skip it in this edition. Regarding Linux availability on bare-metal Apple silicon Macs, you could visit Asahi Linux, a project that aims to bring a fully functional Linux distribution to Apple silicon computers. Asahi Linux is available at https://asahilinux.org/.

In the next section, we briefly illustrate the installation of Ubuntu Server LTS. If we plan to install Ubuntu in a VM, there are some preliminary steps required for provisioning the VM environment. Otherwise, we proceed directly to the Installation section.

VM provisioning using VMware Workstation

In the following steps, we will create a VM based on Ubuntu Server using VMware Workstation on Windows 11. At the time of writing, version 17 of the software is available for both free and commercial use.

The first step after initializing the hypervisor is to click on Create a New Virtual Machine. This will open a new window with the new virtual machine wizard, where you can select the ISO image for the Linux distribution you want to install.

Click Browse and then open the image from your hard drive or download destination.

Click Next and you will have to give a name to the new VM and choose a location on your disk for installation. We will leave the default destination as provided by the hypervisor and name the VM Ubuntu Server 22.04.1.

Click Next. In the following window that appears, you have to give the maximum disk size for the VM. By default, it is set to 20 GB as the recommended size for Ubuntu Server. We will leave it as is.

By clicking Next once more, a window with the VM settings is provided. By default, the hypervisor provides 2 CPU cores and 4 GB of RAM to the VM. You can click on the Customize hardware button to change the defaults, depending on your hardware availability. As a rule, we recommend having at least 16 GB of RAM on your system and an 8-core CPU to be able to create reasonable-sized VMs. When everything is set up as you want, click on the Close button on the lower right side of the window. You are now back to the main wizard window.