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libvirt Wiki

This is the libvirt Wiki for user contributed content.

Due to frequent attacks from spammers who are able to defeat the various anti-spam measures, it has become necessary to disable new account creation.

We still welcome contributions from anyone interested in updating content. Simply send an email to the main libvirt development list asking for an account and one will be created for you with as little delay as practical. Please tell us your preferred wiki user name in the email - if you have no preferences we will create one with "ForenameSurname" style.

General project documentation

• Libvirt FAQ
• Introductory guides to a variety of libvirt topics
• General hints and tips
• Troubleshooting Guide
• Libvirt Docs Team To Do list
• Outstanding feature To Do list
• Switching over from running standalone QEMU to libvirt managed QEMU
• Anatomy of the libvirt library (IBM developerworks)
• Areas to focus on testing

Books

• Book "qemu-kvm & libvirt", ISBN 978-3-8370-0876-0, http://qemu-buch.de

Configuration Management

• Puppet-virt - Puppet Module for Virtualization Management

convert

• Converting VMware guests to libvirt/KVM guests - Blog entry showing how to convert a VMware guest domain to a libvirt/KVM guest domain

Guest Management

Concepts

• Guest (VM) Lifecycle : Read This First - Introduces the concepts used with guests / virtual machines. Includes things like persistent vs transient domains, creating, starting, stopping domains, saving, restoring, snapshots, and secure wiping of disk images.

CGroups

• CGroups usage with QEMU, KVM and LXC guests

CPU

• Guest CPU model configuration with QEMU/KVM
• Guest CPU affinity and NUMA placement on host with QEMU/KVM

KVM / QEMU

• What benefits does libvirt offer to developers targetting QEMU+KVM?
• Many introductory guides to libvirt with KVM
• Introduction to qemu guest agent

Guest device Configuration

• Stable guest machine ABI, PCI addressing and drive controller/disk addressing

Virtio

• Setting up virtio

Host SCSI device

• SCSI generic device passthrough
• vhost-scsi target

NPIV

• NPIV in libvirt

libguestfs / guestfish

• Guestfish: generating inline commands from shell scripts - Blog entry showing how to generate inline guestfish commands from shell scripts
• libguestfs: Live CD inspection - Blog entry showing use of virt-inspector to tell what operating system is on a Live CD image

Networking

Concepts

• Virtual Networking : Read This First - Introduces the concepts and ideas used in libvirts' networking for guests

Detailed networking pieces

• Host sFlow - Open source add-on for exporting sFlow data from guests
• IPtables / firewall usage in libvirt
• Libvirtd_and_dnsmasq - Additional configuration settings needed for running a global dnsmasq in addition to a libvirt controlled one
• Networking hints and tips
• Routed subnets with virtual networking
• Tip: Find the IP address of a virtual machine - Blog entry showing how to get the IP address of a guest domain
• OVS_and_PVLANS - Setup OpenvSwitch Flows to emulate PVLANs
• NSS module - Setup automatic name translation for your domains

Perl

• Sys-Virt - Daniel Berrange's perl module for managing guests

Provisioning

Cobbler

• cucumber-vhost - Automatic provisioning with Cobbler and Cucumber

Foreman

• Foreman - Automatic provisioning with Foreman and libvirt

Remote Management

CIM

• cimtest

QPID

• libvirt-qpid

Security

Host Security

• Securing KVM guests and the host system in RHEL5.5 or as PDF

SSH

• How to set up access to libvirt via SSH
• How to configure PolicyKit access to libvirt through SSH

Transport Layer Security (TLS)

• In depth guide to configuring TLS in libvirt (with many pictures)
• How to set up your VNC client software to use TLS

Storage

iSCSI

• Accessing iSCSI storage pools using virsh
• Accessing iSCSI storage pools using virt-manager

QCow2 disk encryption

• Using qcow2 with encrypted disks with QEMU/KVM

Disk and Memory Snapshots

• Snapshot API Development

Examples of live block operations

• Live disk backup with active blockcommit
• Live merge an entire disk image chain including current active disk

Third Party Libvirt Applications

• Enomaly Elastic Computing Platform (ECP) - Cloud Computing / Infrastructure as a Service Platform based on Libvirt API

Other

Images

The images in this wiki, along with their Inkscape SVG source, are on this page in one place in case you'd like to use or modify them for your own project:

• SVGImages

Debugging

In case you want to turn on debuging in libvirt follow:

• DebugLogs

For other (partially automated) debugging techniques, check

• Debugging

Getting started with Avocado-VT

Avocado-VT (and Avocado) installation

Avocado is the base framework for Avocado-VT. To install it, follow the simple steps documented here. Then install Avocado-VT, as documented on its own Getting Started page.

libvirt Prerequisites

1. To use Avocado-VT with its libvirt backend, the following packages are required: libvirt, virt-install, qemu-kvm, p7zip, genisoimage. Other packages are also recommended: fakeroot, policycoreutils-python-utils.

   When installing libvirt on Fedora, make sure you have the following packages installed: libvirt-client, libvirt-python, libvirt-daemon-kvm, and libvirt-daemon-config-network.

   To help you with copy and paste, here is a command with the complete list of packages needed on a Fedora system:

   dnf install libvirt virt-install qemu-kvm p7zip genisoimage libvirt-client libvirt-python libvirt-daemon-kvm libvirt-daemon-config-network fakeroot policycoreutils-python-utils

2. Start libvirtd service.

   On systems with systemd, run

   systemctl start libvirtd.service

Avocado-VT bootstrap

Now that all packages are installed and services have been started, it's time to bootstrap Avocado-VT test providers, configuration and default image files, by running:

 avocado vt-bootstrap --vt-type=libvirt

For more information on the bootstrap process, please refer to the the Avocado-VT docs.

Running tests

To get an idea of the available tests, run

 avocado list --vt-type=libvirt

And look for the "VT" tests. To actually run some tests (all virsh.help tests), run

 avocado run virsh.help --vt-type=libvirt

Testing self-built libvirt

To test self-built libvirt rather then the one installed in the system, either built a proper package and install it or follow the steps below.

1. Configure libvirt to use the same paths as the system one.

   ./autogen.sh --system

2. Compile libvirt.

   make

3. Change libvirtd service to start your local libvirtd using /path/to/libvirt/run /path/to/libvirt/daemon/.libs/libvirtd. On systems with systemd change ExecStart in /etc/systemd/system/multi-user.target.wants/libvirtd.service. This hack is required for some tests that restart libvirtd service.
4. Run tests using the self-built libvirt:

   /path/to/libvirt/run avocado run virsh.help virsh.console --vt-type libvirt

Getting started with the Wiki

This wiki is using the MediaWiki software. The following links will provide help on wiki syntax and other matters

• Editing Help
• MediaWiki FAQ

Getting started with libvirt development

Here is the list of small tasks that should enable you to start digging into libvirt source code base

Google Summer of Code

There is a separate page dedicated to Google Summer of Code 2019. Also, the list for future ideas for projects can be found here Google Summer of Code Ideas. The previous years can be found here, here and here. There is also a separate page for FAQ.