Book Image

Mastering Ubuntu Server - Second Edition

By : Jay LaCroix
Book Image

Mastering Ubuntu Server - Second Edition

By: Jay LaCroix

Overview of this book

Ubuntu Server has taken the data centers by storm. Whether you're deploying Ubuntu for a large-scale project or for a small office, it is a stable, customizable, and powerful Linux distribution that leads the way with innovative and cutting-edge features. For both simple and complex server deployments, Ubuntu's flexible nature can be easily adapted to meet to the needs of your organization. With this book as your guide, you will learn all about Ubuntu Server, from initial deployment to creating production-ready resources for your network. The book begins with the concept of user management, group management, and filesystem permissions. Continuing into managing storage volumes, you will learn how to format storage devices, utilize logical volume management, and monitor disk usage. Later, you will learn how to virtualize hosts and applications, which will cover setting up KVM/QEMU, as well as containerization with both Docker and LXD. As the book continues, you will learn how to automate configuration with Ansible, as well as take a look at writing scripts. Lastly, you will explore best practices and troubleshooting techniques when working with Ubuntu Server that are applicable to real-world scenarios. By the end of the book, you will be an expert Ubuntu Server administrator who is well-versed in its advanced concepts.
Table of Contents (21 chapters)

Understanding Linux name resolution

In Chapter 7, Setting Up Network Services, we'll have a discussion on setting up a DNS server for local name resolution for your network. But before we get to that, it's also important to understand how Linux resolves names in the first place. Most of you are probably aware of the concept of a Domain Name System (DNS), which matches human-understandable domain names to IP addresses. This makes browsing your network (as well as the internet) much easier. However, a DNS isn't always the first thing that your Linux server will use when resolving names.

For more information on the order in which Ubuntu Server checks resources to resolve names, feel free to take a look at the /etc/nsswitch.conf file. There's a line in this file that begins with the word hosts. Here is the output of the relevant line from the file on my server...