第 8 章 Virtual machine templates

8.1. Creating virtual machine templates

You can use virtual machine templates to create multiple virtual machines that have similar configurations. After a template is created, reference the template when creating virtual machines.

8.1.1. 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 OpenShift Virtualization console, click WorkloadsVirtualization from the side menu.
  2. Click the Virtual Machine Templates tab.
  3. Click Create Template and select New with Wizard.
  4. Fill in all required fields in the General step.
  5. 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.
  6. 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.

      注意

      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.

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

    The template is listed in the Virtual Machine Templates tab.

8.1.2. 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.

8.1.2.1. 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.

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.

Memory

 

Size in GiB of the memory allocated to the virtual machine.

CPUs

 

The amount of CPU allocated to the virtual machine.

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.

8.1.2.2. 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.

Custom script

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

8.1.2.3. Networking fields

NameDescription

Name

Name for the Network Interface Card.

Model

Indicates the model of the Network Interface Card. Supported values are e1000, e1000e, ne2k_pci, pcnet, rtl8139, and virtIO.

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.

8.1.2.4. Storage fields

NameDescription

Source

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

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

Type of disk device. Supported interfaces are virtIO, SATA, and SCSI.

Storage Class

The StorageClass that is used to create the disk.

Advanced → Volume Mode

 

Defines whether the persistent volume uses a formatted file system or raw block state. Default is Filesystem.

Advanced → Access Mode

 

Access mode of the persistent volume. Supported access modes are Single User (RWO), Shared Access (RWX), and Read Only (ROX).

Advanced storage settings

The following advanced storage settings are available for Blank, Import via URL, and Clone existing PVC disks. These parameters are optional. If you do not specify these parameters, the system uses the default values from the kubevirt-storage-class-defaults config map.

NameParameterDescription

Volume Mode

Filesystem

Stores the virtual disk on a filesystem-based volume.

Block

Stores the virtual disk directly on the block volume. Only use Block if the underlying storage supports it.

Access Mode

Single User (RWO)

The disk can be mounted as read/write by a single node.

Shared Access (RWX)

The disk can be mounted as read/write by many nodes.

注意

This is required for some features, such as live migration of virtual machines between nodes.

Read Only (ROX)

The disk can be mounted as read-only by many nodes.