virt-manager

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Resources

The virt-manager application is a desktop user interface for management of virtual machines and containers through the libvirt library.

Virt-manager shows all domains as running or inactive, presents performance data and utilization statistics. Virt-manager enable the easy creation of new domains, storage, network connections. Virt-manager also can reallocate host resources amongst the guest domain.

Virt-manager primarily handles KVM VMs, but also manages Xen and LXC (linux containers).

It presents a summary view of running domains, their live performance & resource utilization statistics.

Wizards enable the creation of new domains, and configuration & adjustment of a domain’s resource allocation & virtual hardware.

An embedded VNC and SPICE client viewer presents a full graphical console to the guest domain [1].

Overview

Firstly, virt-manager is a front-end to QEMU.
virt-manager can create/delete/maintain an instance of many virtual machine (VM).
virt-manager can start/stop a VM or a container.
virt-manager can mount a CD-ROM ISO image.
virt-manager can create different networking connections for the guest OS in VM to use.
virt-manager can create bridges, MACVLAN, static netdev, and NAT'd IP interface.
virt-manager can create/delete/maintain storage pools using many different filesystems such as directory, direct hard drive, gluster, iSCSI, LVM, multi-path devices, netfs, SCSI, RADOS/Ceph, and Sheepdog.

Installation

BIOS/UEFI

Verify that the host hardware has the needed virtualization support, issue the following command:

user $grep --color -E "vmx|svm" /proc/cpuinfo

The vmx or svm CPU flag should be red highlighted and available.

And file /dev/kvm must exist as well:

user $ls /dev/kvm

user $/dev/kvm

Return back to QEMU for compliance.

USE flags

USE flags for app-emulation/virt-manager A graphical tool for administering virtual machines

`gui`	Enable support for a graphical user interface
`policykit`	Enables sys-auth/polkit authentication support, required when using app-emulation/libvirt with PolicyKit authentication
`sasl`	Depend on the proper libraries needed to connect to SASL-enabled libvirtd instances (e.g. Kerberos-protected instances).
`test`	Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)

Data provided by the Gentoo Package Database · Last update: 2022-08-24 21:54 More information about USE flags

Note
If virt-manager is going to be used, be sure to enable the usbredir and spice USE flags on the qemu package for correct operation.

USE_EXPAND

Additional ebuild configuration frobs are provided as the USE_EXPAND variables QEMU_USER_TARGETS and QEMU_SOFTMMU_TARGETS. See app-emulation/qemu for a list of all the available targets (there are a heck of a lot of them; most of them are very obscure and may be ignored; leaving these variables at their default values will disable almost everything which is probably just fine for most users).

For each target specified, a qemu executable will be built. A softmmu target is the standard qemu use-case of emulating an entire system (like VirtualBox or VMWare, but with optional support for emulating CPU hardware along with peripherals). user targets execute user-mode code only; the (somewhat shockingly ambitious) purpose of these targets is to "magically" allow importing user-space linux ELF binaries from a different architecture into the native system (that is, they are like multilib, without the awkward need for a software stack or CPU capable of running it).

In order to enable QEMU_USER_TARGETS and QEMU_SOFTMMU_TARGETS we can edit the variables globally in /etc/portage/make.conf, i.e.:

FILE /etc/portage/make.conf

QEMU_SOFTMMU_TARGETS="arm x86_64 sparc"
QEMU_USER_TARGETS="x86_64"

Or, the /etc/portage/package.use file(s) can be modified. Two equivalent syntaxes are available: traditional USE flag syntax, i.e.:

FILE /etc/portage/package.use

app-emulation/qemu qemu_softmmu_targets_arm qemu_softmmu_targets_x86_64 qemu_softmmu_targets_sparc
app-emulation/qemu qemu_user_targets_x86_64

Another alternative is to use the newer sexy USE_EXPAND-specific syntax:

FILE /etc/portage/package.use

app-emulation/qemu QEMU_SOFTMMU_TARGETS: arm x86_64 sparc QEMU_USER_TARGETS: x86_64

Emerge

root #emerge --ask app-emulation/virt-manager

Additional software

The virt-manager requires the app-emulation/libvirt package. See libvirt for installation.

Usage

To start :

user $virt-manager

To start virt-manager with the configuration window to gentoo guest, using default QEMU UNIX socket connection:

user $virt-manager --connect qemu:///system --show-domain-editor gentoo

Invocation

user $virt-manager --help

usage: virt-manager [options]

optional arguments:
  -h, --help            show this help message and exit
  --version             show program's version number and exit
  -c URI, --connect URI
                        Connect to hypervisor at URI
  --debug               Print debug output to stdout (implies --no-fork)
  --no-fork             Don't fork into background on startup
  --show-domain-creator
                        Show 'New VM' wizard
  --show-domain-editor NAME|ID|UUID
                        Show domain details window
  --show-domain-performance NAME|ID|UUID
                        Show domain performance window
  --show-domain-console NAME|ID|UUID
                        Show domain graphical console window
  --show-domain-delete NAME|ID|UUID
                        Show domain delete window
  --show-host-summary   Show connection details window

Also accepts standard GTK arguments like --g-fatal-warnings

Troubleshooting

TBS

Removal

root #emerge --ask --depclean --verbose app-emulation/virt-manager