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 and local image


In this recipe, we are going to live migrate a running instance, without shared storage.

Getting ready

For this recipe, we are going to need the following:

  • Two libvirt servers with a running KVM instance using a local image file. We are going to use the KVM guest we built in the previous recipe, Offline migration using the virsh command and local image.
  • Both servers must be able to communicate with each other using their hostnames.

How to do it...

To migrate an instance without shared storage, use the following steps:

  1. Ensure that the KVM guest is running:
root@kvm1:~# virsh list --all
 Id   Name              State
----------------------------------------------------
 33   kvm_no_sharedfs   running

root@kvm1:~#
  1. Find the location of the image file:
root@kvm1:~# virsh dumpxml kvm_no_sharedfs | grep "source file"
 <source file='/tmp/kvm_no_sharedfs.img'/>
root@kvm1:~#
  1. Transfer the image file to the destination host:
root@kvm1:~# scp /tmp/kvm_no_sharedfs...