Book Image

Mastering KVM Virtualization - Second Edition

By : Vedran Dakic, Humble Devassy Chirammal, Prasad Mukhedkar, Anil Vettathu
Book Image

Mastering KVM Virtualization - Second Edition

By: Vedran Dakic, Humble Devassy Chirammal, Prasad Mukhedkar, Anil Vettathu

Overview of this book

Kernel-based Virtual Machine (KVM) enables you to virtualize your data center by transforming your Linux operating system into a powerful hypervisor that allows you to manage multiple operating systems with minimal fuss. With this book, you'll gain insights into configuring, troubleshooting, and fixing bugs in KVM virtualization and related software. This second edition of Mastering KVM Virtualization is updated to cover the latest developments in the core KVM components - libvirt and QEMU. Starting with the basics of Linux virtualization, you'll explore VM lifecycle management and migration techniques. You’ll then learn how to use SPICE and VNC protocols while creating VMs and discover best practices for using snapshots. As you progress, you'll integrate third-party tools with Ansible for automation and orchestration. You’ll also learn to scale out and monitor your environments, and will cover oVirt, OpenStack, Eucalyptus, AWS, and ELK stack. Throughout the book, you’ll find out more about tools such as Cloud-Init and Cloudbase-Init. Finally, you'll be taken through the performance tuning and troubleshooting guidelines for KVM-based virtual machines and a hypervisor. By the end of this book, you'll be well-versed with KVM virtualization and the tools and technologies needed to build and manage diverse virtualization environments.
Table of Contents (22 chapters)
Section 1: KVM Virtualization Basics
Section 2: libvirt and ovirt for Virtual Machine Management
Section 3: Automation, Customization, and Orchestration for KVM VMs
Section 4: Scalability, Monitoring, Performance Tuning, and Troubleshooting

Virtio device tuning

In the virtualization world, a comparison is always made with bare-metal systems. Paravirtualized drivers enhance the performance of guests and try to retain near-bare-metal performance. It is recommended to use paravirtualized drivers for fully virtualized guests, especially when the guest is running with I/O-heavy tasks and applications. Virtio is an API for virtual IO and was developed by Rusty Russell in support of his own virtualization solution, called lguest. Virtio was introduced to achieve a common framework for hypervisors for IO virtualization.

In short, when we use paravirtualized drivers, the VM OS knows that there's a hypervisor beneath it, and therefore uses frontend drivers to access it. The frontend drivers are part of the guest system. When there are emulated devices and someone wants to implement backend drivers for these devices, hypervisors do this job. The frontend and backend drivers communicate through a virtio-based path. Virtio...