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)

Backing up and restoring Debian packages

As you maintain your server, your list of installed packages will grow. If, for some reason, you needed to rebuild your server, you would need to reproduce exactly what you had installed before, which can be a pain. It's always recommended that you document all changes made to your server via a change control process, but, at the very least, keeping track of which packages are installed is an absolute must. In some cases, a server may only include one or two extra packages in order to meet its goal, but, in other cases, you may need an exact combination of software and libraries in order to get things working like they were. Thankfully, the dpkg command allows us to export and import a list of packages to install.

To export a list of installed packages, we can use the following command:

dpkg --get-selections > packages.list