Chapter 7. Virtual machine templates

7.1. Creating virtual machine templates

Using Virtual machines templates is an easy way to create multiple virtual machines with similar configuration. After a template is created, reference the template when creating virtual machines.

7.1.1. Creating a virtual machine template with the interactive wizard in the web console

The web console features an interactive wizard that guides you through the General, Networking, Storage, Advanced, and Review steps to simplify the process of creating virtual machine templates. All required fields are marked with a *. The wizard prevents you from moving to the next step until you provide values in the required fields.

Procedure

  1. In the container-native virtualization console, click Workloads → Virtual Machine Templates.
  2. Click Create Template and select New with Wizard.
  3. Fill in all required fields in the General step.

  4. Click Next to progress to the Networking screen. A NIC that is named nic0 is attached by default.

    1. Optional: Click Add Network Interface to create additional NICs.
    2. Optional: You can remove any or all NICs by clicking the Options menu kebab and selecting Delete. Virtual machines created from a template do not need a NIC attached. NICs can be created after a virtual machine has been created.

  5. Click Next to progress to the Storage screen.

    1. Optional: Click Add Disk to create additional disks.
    2. Optional: Click a disk to modify available fields. Click the ✓ button to save the changes.

    3. Optional: Click Disk to choose an available disk from the Select Storage list.

      Note

      If either URL or Container are selected as the Source in the General step, a rootdisk disk is created and attached to virtual machines as the Bootable Disk. You can modify the rootdisk but you cannot remove it.

      A Bootable Disk is not required for virtual machines provisioned from a PXE source if there are no disks attached to the virtual machine. If one or more disks are attached to the virtual machine, you must select one as the Bootable Disk.

  6. Click Create Virtual Machine Template >. The Results screen displays the JSON configuration file for the virtual machine template.

    The template is listed in Workloads → Virtual Machine Templates.

7.1.2. Virtual machine template interactive wizard fields

The following tables describe the fields for the Basic Settings, Networking, and Storage panes in the Create Virtual Machine Template interactive wizard.

7.1.2.1. Virtual machine template wizard fields

NameParameterDescription

Source

PXE

Provision virtual machine from PXE menu. Requires a PXE-capable NIC in the cluster.

URL

Provision virtual machine from an image available from an HTTP or S3 endpoint.

Container

Provision virtual machine from a bootable operating system container located in a registry accessible from the cluster. Example: kubevirt/cirros-registry-disk-demo.

Disk

Provision virtual machine from a disk.

Attach disk

 

Attach an existing disk that was previously cloned or created and made available in the PersistentVolumeClaims. When this option is selected, you must manually complete the Operating System, Flavor, and Workload Profile fields.

Operating System

 

The primary operating system that is selected for the virtual machine.

Flavor

small, medium, large, tiny, Custom

Presets that determine the amount of CPU and memory allocated to the virtual machine. The presets displayed for Flavor are determined by the operating system.

Workload Profile

High Performance

A virtual machine configuration that is optimized for high-performance workloads.

Server

A profile optimized to run server workloads.

Desktop

A virtual machine configuration for use on a desktop.

Name

 

The name can contain lowercase letters (a-z), numbers (0-9), and hyphens (-), up to a maximum of 253 characters. The first and last characters must be alphanumeric. The name must not contain uppercase letters, spaces, periods (.), or special characters.

Description

 

Optional description field.

7.1.2.2. Cloud-init fields

NameDescription

Hostname

Sets a specific host name for the virtual machine.

Authenticated SSH Keys

The user’s public key that is copied to ~/.ssh/authorized_keys on the virtual machine.

Use custom script

Replaces other options with a field in which you paste a custom cloud-init script.

7.1.2.3. Networking fields

NameDescription

Name

Name for the Network Interface Card.

Model

Driver for the Network Interface Card or model for the Network Interface Card.

Network

List of available NetworkAttachmentDefinition objects.

Type

List of available binding methods. For the default Pod network, masquerade is the only recommended binding method. For secondary networks, use the bridge binding method. The masquerade method is not supported for non-default networks.

MAC Address

MAC address for the Network Interface Card. If a MAC address is not specified, an ephemeral address is generated for the session.

7.1.2.4. Storage fields

NameDescription

Source

Select a blank disk for the virtual machine or choose from the options available: PXE, Container, URL or Disk. To select an existing disk and attach it to the virtual machine, choose Attach Disk from a list of available PersistentVolumeClaims (PVCs) or from a cloned disk.

Name

Name of the disk. The name can contain lowercase letters (a-z), numbers (0-9), hyphens (-), and periods (.), up to a maximum of 253 characters. The first and last characters must be alphanumeric. The name must not contain uppercase letters, spaces, or special characters.

Size (GiB)

Size, in GiB, of the disk.

Interface

Name of the interface.

Storage class

Name of the underlying StorageClass.

7.2. Editing virtual machine templates

You can update a virtual machine template in the web console, either by editing the full configuration in the YAML editor or by editing a subset of the parameters in the Virtual Machine Template Overview screen.

7.2.1. Editing a virtual machine template in the web console

Edit select values of a virtual machine template in the Virtual Machine Template Overview screen of the web console by clicking on the pencil icon next to the relevant field. Other values can be edited using the CLI.

Procedure

  1. Click Workloads → Virtual Machine Templates from the side menu.
  2. Select a virtual machine template to open the Virtual Machine Template Overview screen.
  3. Click the pencil icon to make that field editable.
  4. Make the relevant changes and click Save.

Editing a virtual machine template will not affect virtual machines already created from that template.

7.2.2. Editing virtual machine template YAML configuration in the web console

You can edit the YAML configuration of a virtual machine template from the web console.

Not all parameters can be modified. If you click Save with an invalid configuration, an error message indicates the parameter that cannot be modified.

Note

Navigating away from the YAML screen while editing cancels any changes to the configuration that you made.

Procedure

  1. In the container-native virtualization console, click Workloads → Virtual Machine Templates.
  2. Select a template.
  3. Click the YAML tab to display the editable configuration.
  4. Edit the file and click Save.

A confirmation message, which includes the updated version number for the object, shows the modification has been successful.

7.2.3. Adding a virtual disk to a virtual machine template

Use this procedure to add a virtual disk to a virtual machine template.

Procedure

  1. From the Virtual Machine Templates tab, select your virtual machine template.
  2. Select the Disks tab.
  3. Click Add Disks to open the Add Disk window.
  4. In the Add Disk window, specify Source, Name, Size, Interface, and Storage Class.
  5. Use the drop-down lists and check boxes to edit the disk configuration.
  6. Click OK.

7.2.4. Adding a network interface to a virtual machine template

Use this procedure to add a network interface to a virtual machine template.

Procedure

  1. From the Virtual Machine Templates tab, select the virtual machine template.
  2. Select the Network Interfaces tab.
  3. Click Add Network Interface.
  4. In the Add Network Interface window, specify the Name, Model, Network, Type, and MAC Address of the network interface.
  5. Click Add to add the network interface.
  6. Restart the virtual machine to enable access.
  7. Edit the drop-down lists and check boxes to configure the network interface.
  8. Click Save Changes.
  9. Click OK.

The new network interface displays at the top of the Create Network Interface list until the user restarts it.

The new network interface has a Pending VM restart Link State until you restart the virtual machine. Hover over the Link State to display more detailed information.

The Link State is set to Up by default when the network interface card is defined on the virtual machine and connected to the network.

7.2.5. Editing CD-ROMs for Virtual Machine Templates

Use the following procedure to configure CD-ROMs for virtual machines.

Procedure

  1. From the Virtual Machine Templates tab, select your virtual machine template.
  2. Select the Overview tab.

  3. Click the pencil icon to the right of the CD-ROMs label to open the Edit CD-ROM window.

    • If no CD-ROMs are available for editing, the CD label initially displays blank.
    • If there are CD-ROMs available, you can eject the CD-ROM by clicking Eject CD-ROM or remove it by clicking -.

  4. In the Edit CD-ROM window, do the following:

    1. Select the type of CD-ROM configuration in the Media Type field.

      • On Windows systems, Windows guest tools is attached by default in the Media Type field.
    2. Complete the required information for each Media Type.
    3. Click Add CD-ROM.
  5. When all CD-ROMs are added, click Save.

7.3. Deleting a virtual machine template

You can delete a virtual machine template in the web console.

7.3.1. Deleting a virtual machine template in the web console

Deleting a virtual machine template permanently removes it from the cluster.

Procedure

  1. In the container-native virtualization console, click Workloads → Virtual Machine Templates.

  2. You can delete the virtual machine template from this pane, which makes it easier to perform actions on multiple templates in the one pane, or from the Virtual Machine Template Details pane where you can view comprehensive details of the selected template:

    • Click the Options menu kebab of the template to delete and select Delete Template.
    • Click the template name to open the Virtual Machine Template Details pane and click Actions → Delete Template.
  3. In the confirmation pop-up window, click Delete to permanently delete the template.