17-08-2021

Virt-manager

If you plan to create a virtual machine image on a machine thatcan run X11 applications, the simplest way to do so is to usethe virt-manager GUI, which is installable as thevirt-manager package on both Fedora-based and Debian-based systems.This GUI has an embedded VNC client that will let you view andinteract with the guest’s graphical console.

See full list on linux.die.net. Virt-manager is a desktop tool for managing virtual machines. It provides the ability to control the lifecycle of existing machines. Use the virt-manager X11 GUI¶. If you plan to create a virtual machine image on a machine that can run X11 applications, the simplest way to do so is to use the virt-manager GUI, which is installable as the virt-manager package on both Fedora-based and Debian-based systems.

If you are building the image on a headless server, andyou have an X server on your local machine, you can launchvirt-manager using ssh X11 forwarding to access the GUI.Since virt-manager interacts directly with libvirt, you typicallyneed to be root to access it. If you can ssh directly in as root(or with a user that has permissions to interact with libvirt), do:

If the account you use to ssh into your server does not havepermissions to run libvirt, but has sudo privileges, do:

Note

The -X flag passed to ssh will enable X11 forwarding over ssh.If this does not work, try replacing it with the -Y flag.

Click the Create a new virtual machine button at the top-left,or go to File ‣ New Virtual Machine. Then, follow theinstructions.

You will be shown a series of dialog boxes that will allow youto specify information about the virtual machine.

Note

Virt-manager

When using qcow2 format images, you should check the optionCustomizeconfigurationbeforeinstall, go to disk properties andexplicitly select the qcow2 format.This ensures the virtual machine disk size will be correct.

Introduction

The virt-manager source contains not only virt-manager itself but also a collection of further helpful tools like virt-install, virt-clone and virt-viewer.

Virtual Machine Manager

The virt-manager package contains a graphical utility to manage local and remote virtual machines. To install virt-manager enter:

Since virt-manager requires a Graphical User Interface (GUI) environment it is recommended to be installed on a workstation or test machine instead of a production server. To connect to the local libvirt service enter:

You can connect to the libvirt service running on another host by entering the following in a terminal prompt:

Note

The above example assumes that SSH connectivity between the management system and the target system has already been configured, and uses SSH keys for authentication. SSH keys are needed because libvirt sends the password prompt to another process.

virt-manager guest lifecycle

Virt-manager Create Virtual Network

When using virt-manager it is always important to know the context you look at.
The main window initially lists only the currently defined guests, you’ll see their name, state and a small chart on cpu usage.

On that context there isn’t much one can do except start/stop a guest.
But by double-clicking on a guest or by clicking the open button at the top one can see the guest itself. For a running guest that includes the guests main-console/virtual-screen output.

If you are deeper in the guest config a click in the top left onto “show the graphical console” will get you back to this output.

virt-manager guest modification

virt-manager provides a gui assisted way to edit guest definitions which can be handy.
To do so the per-guest context view will at the top have “show virtual hardware details”.
Here a user can edit the virtual hardware of the guest which will under the cover alter the guest representation.

The UI edit is limited to the features known and supported to that GUI feature. Not only does libvirt grow features faster than virt-manager can keep up - adding every feature would also overload the UI to the extend to be unusable. To strike a balance between the two there also is the XML view which can be reached via the “edit libvirt XML” button.

By default this will be read-only and you can see what the UI driven actions have changed, but one can allow RW access in this view in the preferences.
This is the same content that the virsh edit of the libvirt-client exposes.

Virtual Machine Viewer

Virt-manager ubuntu

The virt-viewer application allows you to connect to a virtual machine’s console like virt-manager reduced to the GUI functionality. virt-viewer does require a Graphical User Interface (GUI) to interface with the virtual machine.

To install virt-viewer from a terminal enter:

Once a virtual machine is installed and running you can connect to the virtual machine’s console by using:

The UI will be a window representing the virtual screen of the guest, just like virt-manager above but without the extra buttons and features around it.

Similar to virt-manager, virt-viewer can connect to a remote host using SSH with key authentication, as well:

Be sure to replace web_devel with the appropriate virtual machine name.

If configured to use a bridged network interface you can also setup SSH access to the virtual machine.

virt-install

virt-install is part of the virtinst package.
It can help installing classic ISO based systems and provides a CLI options for the most common options needed to do so. To install it, from a terminal prompt enter:

sudo apt install virtinst

There are several options available when using virt-install. For example:

There are much more arguments that can be found in the man page, explaining those of the example above one by one:

  • -n web_devel
    the name of the new virtual machine will be web_devel in this example.
  • -r 8192
    specifies the amount of memory the virtual machine will use in megabytes.
  • –disk path=/home/doug/vm/web_devel.img,bus=virtio,size=50
    indicates the path to the virtual disk which can be a file, partition, or logical volume. In this example a file named web_devel.img in the current users directory, with a size of 50 gigabytes, and using virtio for the disk bus. Depending on the disk path, virt-install my need to be run with elevated privileges.
  • -c focal-desktop-amd64.iso
    file to be used as a virtual CDROM. The file can be either an ISO file or the path to the host’s CDROM device.
  • –network
    provides details related to the VM’s network interface. Here the default network is used, and the interface model is configured for virtio.
  • –video=vmvga
    the video driver to use.
  • –graphics vnc,listen=0.0.0.0
    exports the guest’s virtual console using VNC and on all host interfaces. Typically servers have no GUI, so another GUI based computer on the Local Area Network (LAN) can connect via VNC to complete the installation.
  • –noautoconsole
    will not automatically connect to the virtual machine’s console.
  • -v: creates a fully virtualized guest.
  • –vcpus=4
    allocate 4 virtual CPUs.

After launching virt-install you can connect to the virtual machine’s console either locally using a GUI (if your server has a GUI), or via a remote VNC client from a GUI-based computer.

virt-clone

The virt-clone application can be used to copy one virtual machine to another. For example:

virt-clone --auto-clone --original focal

Options used:

  • –auto-clone: to have virt-clone come up with guest names and disk paths on its own
  • –original: name of the virtual machine to copy

Also, use -d or --debug option to help troubleshoot problems with virt-clone.

Replace focal and with appropriate virtual machine names of your case.

Virt-manager Create Virtual Network

Warning: please be aware that this is a full clone, therefore any sorts of secrets, keys and for example /etc/machine-id will be shared causing e.g. issues to security and anything that needs to identify the machine like DHCP. You most likely want to edit those afterwards and de-duplicate them as needed.

Virt-manager

Ubuntu Virt-manager

Resources

Virt-manager

  • See the KVM home page for more details.

  • For more information on libvirt see the libvirt home page

  • The Virtual Machine Manager site has more information on virt-manager development.

Virt Manager Lxc

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