Birmingham mumbai

612
Setting up a firewall 
615
Encrypting and decrypting disks with LUKS 
619
Locking down sudo 
621
Summary 622
Further reading 
623
Chapter 22: Troubleshooting Ubuntu Servers 
625
Evaluating the scope 
626
Conducting a root cause analysis 
628
Viewing system logs 
630
Tracing network issues 
634
Troubleshooting resource issues 
640
Diagnosing defective RAM 
644
Summary 646
Further reading 
647
Chapter 23: Preventing Disasters 
649
Preventing disasters 
649
Utilizing Git for configuration management 
651
Implementing a backup plan 
658
Replacing failed RAID disks 
661
Utilizing bootable recovery media 
665
Summary 666
Further reading 
667
Another Book You May Enjoy 
669
Index 671

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[
 ix 
]
Preface
Ubuntu is an exciting platform. You can literally find it everywhere—desktops, 
laptops, phones, and especially servers. The server edition enables administrators 
to create efficient, flexible, and highly available servers that empower organizations 
with the power of open source. As Ubuntu administrators, we're in good company—
according to W3Techs, Ubuntu is the most widely deployed distribution on the web 
with regard to Linux. With the release of Ubuntu 20.04, this platform becomes even 
more exciting!
In this book, we will dive right into Ubuntu Server, and you will learn all the 
concepts needed to manage your servers and configure them to perform all kinds 
of neat tasks, such as serving web pages, managing virtual machines, running 
containers, automating configuration, sharing files with other users, and even 
running Ubuntu in the cloud.
We'll start our journey with the first chapter, where we'll walk through the 
installation of Ubuntu Server 20.04, which will serve as a foundation for the rest 
of the book. As we proceed through our journey, we'll look at managing users, 
connecting to networks, and controlling processes. Later, we'll implement important 
technologies, such as DHCP, DNS, Apache, MariaDB, and more. We'll even set up 
our own Nextcloud server along the way.
Finally, the end of the book covers various things we can do to troubleshoot issues, 
as well as preventing and recovering from disasters.