Book Image

KVM Virtualization Cookbook

Book Image

KVM Virtualization Cookbook

Overview of this book

Virtualization technologies such as KVM allow for better control over the available server resources, by deploying multiple virtual instances on the same physical host, or clusters of compute resources. With KVM it is possible to run various workloads in isolation with the hypervisor layer providing better tenant isolation and higher degree of security. This book will provide a deep dive into deploying KVM virtual machines using qemu and libvirt and will demonstrate practical examples on how to run, scale, monitor, migrate and backup such instances. You will also discover real production ready recipes on deploying KVM instances with OpenStack and how to programatically manage the life cycle of KVM virtual machines using Python. You will learn numerous tips and techniques which will help you deploy & plan the KVM infrastructure. Next, you will be introduced to the working of libvirt libraries and the iPython development environment. Finally, you will be able to tune your Linux kernel for high throughput and better performance. By the end of this book, you will gain all the knowledge needed to be an expert in working with the KVM virtualization infrastructure.
Table of Contents (15 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Managing volumes


In the previous recipe, we saw how to create new storage pools, add a volume to it, and create a new KVM instance using that volume. In this recipe, we are going to focus on manipulating volumes that are a part of an existing storage pool. Strictly speaking, we are not required to use storage pools and volumes in order to build VMs. We can use other tools to manage and manipulate the virtual instance images, such as the qemu-img utility. Using volumes is just a convenience for having a centralized storage repository of various backend types.

Getting ready

The main requirement of this recipe is to have an existing storage pool with the directory backend. If you skipped the previous recipe, now is that time to create a new one, as we'll be using it to manipulate volumes.

How to do it...

To create, inspect and assign volumes to an instance, run the following:

  1. List the available storage pools:
root@kvm:~# virsh pool-list --all
 Name            State  Autostart
-------------------...