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

Understanding macvtap

This module works like a combination of the tap and macvlan modules. We already explained what the tap module does. The macvlan module enables us to create virtual networks that are pinned to a physical network interface (usually, we call this interface a lower interface or device). Combining tap and macvlan enables us to choose between four different modes of operation, called Virtual Ethernet Port Aggregator (VEPA), bridge, private, and passthru.

If we're using the VEPA mode (default mode), the physical switch has to support VEPA by supporting hairpin mode (also called reflective relay). When a lower device receives data from a VEPA mode macvlan, this traffic is always sent out to the upstream device, which means that traffic is always going through an external switch. The advantage of this mode is the fact that network traffic between virtual machines becomes visible on the external network, which can be useful for a variety of reasons. You can check...