Book Image

KVM Virtualization Cookbook

By : Konstantin Ivanov
Book Image

KVM Virtualization Cookbook

By: Konstantin Ivanov

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

Online migration using the virsh command with shared storage


The virsh command provides a migrate parameter that we can use to migrate KVM instances between hosts. In the previous two recipes, we saw how to migrate instances manually with downtime. In this recipe, we are going to perform a live migration on an instance that uses either the iSCSI storage pool or the GlusterFS shared volumes that we used earlier in this chapter.

If you recall, live migration only works when the guest filesystem resides on some sort of shared media, such as NFS, iSCSI, GlusterFS, or if we first copy the image file to all nodes and use the --copy-storage-all option with virsh migrate, as we'll see later in this chapter.

Getting ready

In order to complete this recipe, we are going to need the following:

  • Two libvirt hosts with a shared storage between them. If you've completed the earlier recipes in this chapter, you can either use the iSCSI storage pool we created and the KVM instance that is using it or the GFS...