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
About the Author
About the Reviewer
Customer Feedback

Autostarting KVM instances

Once a KVM instance has been defined and started, it will run until the host OS is up. Once the host OS restarts, instances build with libvirt will not automatically start once the host is up and the libvirt daemon is running. In this recipe, we are going to change this behavior and ensure virtual instance start when the libvirt daemon starts.

Getting ready

For this recipe, we are going to need a single KVM instance build with libvirt.

How to do it...

To configure a KVM guest to automatically start after a server, or libvirtd restart, run the following:

  1. Enable the VM autostart:
root@kvm:~# virsh autostart kvm1
Domain kvm1 marked as autostarted

  1. Obtain information for the instance:
root@kvm:~# virsh dominfo kvm1
Id: 31
Name: kvm1
UUID: 6ad84d8a-229d-d1f6-ecfc-d29a25fcfa03
OS Type: hvm
State: running
CPU(s): 2
CPU time: 10.9s
Max memory: 2097152 KiB
Used memory: 1048576 KiB
Persistent: yes
Autostart: enable
Managed save: no
Security model: none
Security DOI:...