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)
1
Section 1: KVM Virtualization Basics
4
Section 2: libvirt and ovirt for Virtual Machine Management
11
Section 3: Automation, Customization, and Orchestration for KVM VMs
15
Section 4: Scalability, Monitoring, Performance Tuning, and Troubleshooting

Network I/O tuning

What we've seen in most KVM environments is that all the network traffic from a guest will take a single network path. There won't be any traffic segregation, which causes congestion in most KVM setups. As a first step for network tuning, we'd advise trying different networks or dedicated networks for management, backups, or live migration. But when you have more than one network interface for your traffic, please try to avoid multiple network interfaces for the same network or segment. If this is at all in play, apply some network tuning that is common for such setups; for example, use arp_filter to control ARP Flux. ARP Flux happens when a VM has more than one network interface and is using them actively to reply to ARP requests, so we should do the following:

echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter 

After that, you need to edit /etc/sysctl.conf to make this setting persistent.

For more information on ARP Flux, please refer to...