libvirt: RPM Deployment Guidance
Description: libvirt, virtualization, virtualization API

# RPM Deployment Guidance

Contents

- RPM packages
- Deployment choices
  - Client only install
  - Every possible virt driver
  - Full features for one virt driver
  - Minimal features for one virt driver

A complete libvirt build includes a wide range of features, many of which are dynamically loadable at runtime. Applications using libvirt typically only need to use a subset of these features, and so do not require a full install of all libvirt RPM packages.

This document provides some guidance on the RPM packages available with libvirt on Fedora and related distributions, to enable applications and administrators to pick the optimal set for their needs.

The RHEL and CentOS distributions use the same RPM packaging split, but many of the drivers will be disabled at build time, so not all of the packages listed on this page will exist.

# RPM packages

- libvirt

  This is an empty package that exists solely as a convenient way to install every other libvirt RPM package. Almost every deployment scenario would be better served by picking one of the other RPMs listed below.

- libvirt-admin

  The virt-admin tool, used for administrative operations on any libvirt daemons. Most usefully it allows for logging filters and outputs to be reconfigured on a running daemon without a restart. This is recommended to be installed on any host running a libvirt daemon.

- libvirt-bash-completion

  Argument auto-completion support for the Bash shell. This is shared code that is pulled in by either the libvirt-admin or libvirt-clients RPMs, so there is no need to explicitly ask for this package to be installed.

- libvirt-client

  The virsh tool, used for interacting with any libvirt driver, both primary virt drivers and secondary drivers for storage, networking, etc. All libvirt installs should have this installed as it provides a useful way to view and debug what is being done by other applications using libvirt.

- libvirt-daemon

  The monolithic libvirtd daemon, traditionally used for running all the stateful drivers. This package does not contain any drivers, so further packages need to be installed to provide the desired drivers.

- libvirt-daemon-config-network

  The sample configuration file providing the 'default' virtual network that enables outbound NAT based connectivity for virtual machines. This is useful on desktop installations, but is not typically desired on server installations where VMs will use full bridged connectivity.

- libvirt-daemon-config-nwfilter

  The sample configuration files providing the network filters for protecting against common malicious guest traffic. This includes protection against ARP, MAC and IP spoofing. This is typically desired on server installations, if the mgmt app is using libvirt's network filtering features.

- libvirt-daemon-driver-interface

  The dynamically loadable driver providing an implementation of the host network interface management APIs, as well as the virtinterfaced daemon binary.

- libvirt-daemon-driver-libxl

  The dynamically loadable driver providing an implementation of the hypervisor APIs for Xen using the libxl library, as well as the virtxend daemon binary.

  Note that this is a minimal package so does not actually pull in the full Xen hypervisor package set. This be must requested separately.

- libvirt-daemon-driver-lxc

  The dynamically loadable driver providing an implementation of the hypervisor APIs for Linux containers, as well as the virtlxcd daemon binary.

- libvirt-daemon-driver-network

  The dynamically loadable driver providing an implementation of the virtual network interface management APIs, as well as the virtinterfaced daemon binary. Typically the libvirt-daemon-config-network RPM will also be desired when this is installed.

- libvirt-daemon-driver-nodedev

  The dynamically loadable driver providing an implementation of the host device management APIs, as well as the virtnodedevd daemon binary.

- libvirt-daemon-driver-nwfilter

  The dynamically loadable driver providing an implementation of the host network firewall management APIs, as well as the virtnwfilterd daemon binary.

- libvirt-daemon-driver-qemu

  The dynamically loadable driver providing an implementation of the hypervisor network interface management APIs, as well as the virtqemud daemon binary.

  Note that this is a minimal package so does not actually pull in the full QEMU or KVM package set. This be must requested separately.

- libvirt-daemon-driver-secret The dynamically loadable driver providing an implementation of the secret data management APIs, as well as the virtsecretd daemon binary.

- libvirt-daemon-driver-storage

  This is an empty package that exists only as a convenient way to request installation of all the storage pool drivers.

  If the application only supports a subset of storage pool types, then a smaller install footprint can be obtained by requesting the individual drivers.

- libvirt-daemon-driver-storage-core

  The dynamically loadable driver providing an implementation of the host storage pool/volume management APIs, as well as the virtstoraged daemon binary.

  Note that this is a minimal package so does not actually pull in any pool implementations.

- libvirt-daemon-driver-storage-disk

  The dynamically loadable driver providing an implementation of the disk partition storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-gluster

  The dynamically loadable driver providing an implementation of the GlusterFS file storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-iscsi

  The dynamically loadable driver providing an implementation of the ISCSI disk storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-iscsi-direct

  The dynamically loadable driver providing an implementation of the ISCSI network storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-logical

  The dynamically loadable driver providing an implementation of the LVM storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-mpath

  The dynamically loadable driver providing an implementation of the multipath disk storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-rbd

  The dynamically loadable driver providing an implementation of the RBD network storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-scsi

  The dynamically loadable driver providing an implementation of the SCSI disk storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-sheepdog

  The dynamically loadable driver providing an implementation of the SheepDog network storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-storage-zfs

  The dynamically loadable driver providing an implementation of the ZFS file storage pool type, for the storage pool management APIs.

- libvirt-daemon-driver-vbox

  The dynamically loadable driver providing an implementation of the host network interface management APIs, as well as the virtinterfaced daemon binary.

- libvirt-daemon-kvm

  This is an empty package that exists only as a convenient way to request installation of all the libvirt features that are relevant to the management of KVM guests. This includes the QEMU driver, and the secondary drivers for secrets, storage pools, virtual networks, host interfaces, host devices and network filtering.

  It will also pull in the full set of QEMU features that can be utilized with native architecture KVM guests.

  This is a good default for an installation to use KVM if the specific set of required features is not known. To have finer grained control over the features, the subset of libvirt-daemon-driver-XXX packages should be used instead.

- libvirt-daemon-lxc

  This is an empty package that exists only as a convenient way to request installation of all the libvirt features that are relevant to the management of Linux containers. This includes the LXC driver, and the secondary drivers for secrets, storage pools, virtual networks, host interfaces, host devices and network filtering.

  This is a good default for an installation to use LXC if the specific set of required features is not known. To have finer grained control over the features, the subset of libvirt-daemon-driver-XXX packages should be used instead.

- libvirt-daemon-qemu

  This is an empty package that exists only as a convenient way to request installation of all the libvirt features that are relevant to the management of QEMU guests. This includes the QEMU driver, and the secondary drivers for secrets, storage pools, virtual networks, host interfaces, host devices and network filtering.

  It will also pull in the full set of QEMU features that can be utilized to emulate any guests architecture supported by QEMU.

  This is a good default for an installation to use QEMU if the specific set of required features is not known. To have finer grained control over the features, the subset of libvirt-daemon-driver-XXX packages should be used instead.

- libvirt-daemon-vbox

  This is an empty package that exists only as a convenient way to request installation of all the libvirt features that are relevant to the management of KVM guests. This includes the QEMU driver, and the secondary drivers for secrets, storage pools, virtual networks, host interfaces, host devices and network filtering.

  This is a good default for an installation to use VirtualBox if the specific set of required features is not known. To have finer grained control over the features, the subset of libvirt-daemon-driver-XXX packages should be used instead.

- libvirt-daemon-xen

  This is an empty package that exists only as a convenient way to request installation of all the libvirt features that are relevant to the management of KVM guests. This includes the QEMU driver, and the secondary drivers for secrets, storage pools, virtual networks, host interfaces, host devices and network filtering.

  It will also pull in the full set of Xen features that can be utilized with Xen guests.

  This is a good default for an installation to use Xen if the specific set of required features is not known. To have finer grained control over the features, the subset of libvirt-daemon-driver-XXX packages should be used instead.

- libvirt-devel

  The header files required to build applications, or language bindings against the libvirt C library. This should never be required on a production host, only development hosts.

- libvirt-docs

  A local copy of the libvirt website website content that matches the deployed version of libvirt.

- libvirt-libs

  The ELF libraries providing the main application interface to libvirt. These have stateless drivers (VMWare ESX, HyperV, etc) built-in, and are able to take to the libvirt daemons to utilize stateful drivers (QEMU, Xen, BHyve, LXC, VZ, etc). This is needed on all libvirt hosts, both client and server.

- libvirt-lock-sanlock

  A plugin for locking disks that communicates with the sanlock daemon. It is optional and only relevant to hosts with the QEMU driver and oVirt management application.

- libvirt-login-shell

  A simple login shell that automatically spawns an LXC container for the user logging in and places them in a shell inside that container.

- libvirt-nss

  A NSS plugin that provides hostname resolution for guests attached to a libvirt virtual network. It is recommended to be installed on any host with guests using the libvirt virtual network connectivity.

- libvirt-wireshark

  A wireshark plugin that allows for dissecting the XDR based RPC protocol used between libvirt and its daemons. Since production deployments should all be using a TLS encrypted, this only useful for development hosts with a libvirt daemon configured without encryption.

# Deployment choices

## Client only install

If an application is capable of using multiple different virtualization drivers it is undesirable to force the installation of a specific set of drivers. In this case the application will merely wish to request a client only install

Alternatively if an application is intended to communicate with a hypervisor on a remote host there is no need to install drivers locally, only a client is needed

The only required package is the libvirt-libs, however, it is useful to also install libvirt-client.

## Every possible virt driver

There is rarely a need to install every virt driver at once on a given host. In the unlikely event that this is needed, however, the libvirt package should be installed.

Note that this doesn't actually pull in the hypervisors, only the libvirt code to talk to the hypervisors.

## Full features for one virt driver

This is a common default installation profile when there is no need to minimise the on-disk footprint.

This is achieved by installing the libvirt-daemon-XXXX package for the virtualization driver that is desired. This will also pull in the default set of hypervisor packages too.

Since this installs every possible libvirt feature for the virtualization driver in question, the on-disk footprint is quite large. The in-memory footprint of the daemons is also relatively large since alot of code is loaded.

## Minimal features for one virt driver

This is the best installation profile when it is desired to minimize the on-disk footprint.

This is achieved by installing the individual libvirt-daemon-driver-XXX packages needed for the features that will be used. This will not pull in the hypervisor packages, allowing a fine grained set of hypervisor features to be chosen separately.

Since this allows fine grained installation of individual libvirt drivers, this results in the lowest on-disk footprint. The in-memory footprint of the daemons is also minimized by reducing the code loaded.

As an example, the smallest possible installation for running KVM guests can be achieved by installing libvirt-daemon-driver-qemu and qemu-kvm-core. This will exclude all the secondary libvirt drivers for storage, networking and host devices, leaving only the bare minimum functionality for managing KVM guests.