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

CPU performance options

There are a few methods to control CPU allocation and the available CPU cycles for KVM machines-using cgroups and the libvirt-provided CPU pinning and affinity functions, we are going to explore in this recipe. CPU affinity is a scheduler property that connects a process to a given set of CPUs on the host OS.

When provisioning virtual machines with libvirt, the default behavior is to provision the guests on any available CPU cores. In some cases, Non-Uniform Memory Access (NUMA) is a good example of when we need to designate a core per KVM instance (as we are going to see in the next recipe), that it's better to assign the virtual machine to a specified CPU core. Since each KVM virtual machine is a kernel process (qemu-system-x86_64 more specifically in our examples), we can do this using tools such as taskset or the virsh command. We can also use the cgroups CPU subsystem to manage CPU cycle allocation, which provides more granular control over CPU resource utilization...