Creating virtual machine templates

About virtual machine templates

Preconfigured Red Hat virtual machine templates are listed in the Templates tab within the Virtualization page. These templates are available for different versions of Red Hat Enterprise Linux, Fedora, Microsoft Windows 10, and Microsoft Windows Servers. Each Red Hat virtual machine template is preconfigured with the operating system image, default settings for the operating system, flavor (CPU and memory), and workload type (server).

The Templates tab displays four types of virtual machine templates:

• Red Hat Supported templates are fully supported by Red Hat.

• User Supported templates are Red Hat Supported templates that were cloned and created by users.

• Red Hat Provided templates have limited support from Red Hat.

• User Provided templates are Red Hat Provided templates that were cloned and created by users.

Using a Red Hat template is convenient because the template is already preconfigured. When you select a Red Hat template to create your own custom template, the Create Virtual Machine Template wizard prompts you to add a boot source if a boot source was not added previously. Then, you can either save your custom template or continue to customize it and save it.

You can also select the Create Virtual Machine Template wizard directly and create a custom virtual machine template. The wizard prompts you to provide configuration details for the operating system, flavor, workload type, and other settings. You can add a boot source and continue to customize your template and save it.

About virtual machines and boot sources

Virtual machines consist of a virtual machine definition and one or more disks that are backed by data volumes. Virtual machine templates enable you to create virtual machines using predefined virtual machine specifications.

Every virtual machine template requires a boot source, which is a fully configured virtual machine disk image including configured drivers. Each virtual machine template contains a virtual machine definition with a pointer to the boot source. Each boot source has a predefined name and namespace. For some operating systems, a boot source is automatically provided. If it is not provided, then an administrator must prepare a custom boot source.

To use the boot sources feature, install the latest release of OKD Virtualization. The namespace openshift-virtualization-os-images enables the feature and is installed with the OKD Virtualization Operator. Once the boot source feature is installed, you can create boot sources, attach them to templates, and create virtual machines from the templates.

Define a boot source by using a persistent volume claim (PVC) that is populated by uploading a local file, cloning an existing PVC, importing from a registry, or by URL. Attach a boot source to a virtual machine template by using the web console. After the boot source is attached to a virtual machine template, you create any number of fully configured ready-to-use virtual machines from the template.

Adding a boot source for a virtual machine template

A boot source can be configured for any virtual machine template that you want to use for creating virtual machines or custom templates. When virtual machine templates are configured with a boot source, they are labeled Available in the Templates tab. After you add a boot source to a template, you can create a new virtual machine from the template.

There are four methods for selecting and adding a boot source in the web console:

• Upload local file (creates PVC)

• Import via URL (creates PVC)

• Clone existing PVC (creates PVC)

• Import via Registry (creates PVC)

Prerequisites

• To add a boot source, you must be logged in as a user with the os-images.kubevirt.io:edit RBAC role or as an administrator. You do not need special privileges to create a virtual machine from a template with a boot source added.

• To upload a local file, the operating system image file must exist on your local machine.

• To import via URL, access to the web server with the operating system image is required. For example: the Red Hat Enterprise Linux web page with images.

• To clone an existing PVC, access to the project with a PVC is required.

• To import via registry, access to the container registry is required.

Procedure

1. In the OKD Virtualization console, click Workloads → Virtualization from the side menu.

2. Click the Templates tab.

3. Identify the virtual machine template for which you want to configure a boot source and click Add source.

4. In the Add boot source to template window, click Select boot source, select a method for creating a persistent volume claim (PVC): Upload local file, Import via URL, Clone existing PVC, or Import via Registry.

5. Optional: Click This is a CD-ROM boot source to mount a CD-ROM and use it to install the operating system on to an empty disk. The additional empty disk is automatically created and mounted by OKD Virtualization. If the additional disk is not needed, you can remove it when you create the virtual machine.

6. Enter a value for Persistent Volume Claim size to specify the PVC size that is adequate for the uncompressed image and any additional space that is required.

   1. Optional: Enter a name for Source provider to associate the name with this template.

   2. Optional: Advanced Storage settings: Click Storage class and select the storage class that is used to create the disk. Typically, this storage class is the default storage class that is created for use by all PVCs.

   3. Optional: Advanced Storage settings: Click Access mode and select an access mode for the persistent volume:

      • Single User (RWO) mounts the volume as read-write by a single node.

      • Shared Access (RWX) mounts the volume as read-write by many nodes.

      • Read Only (ROX) mounts the volume as read-only by many nodes.

   4. Optional: Advanced Storage settings: Click Volume mode if you want to select Block instead of the default value Filesystem. OKD Virtualization can statically provision raw block volumes. These volumes do not have a file system, and can provide performance benefits for applications that either write to the disk directly or implement their own storage service.

7. Select the appropriate method to save your boot source:

   1. Click Save and upload if you uploaded a local file.

   2. Click Save and import if you imported content from a URL or the registry.

   3. Click Save and clone if you cloned an existing PVC.

Your custom virtual machine template with a boot source is listed in the Templates tab, and you can create virtual machines by using this template.

Virtual machine template fields for adding a boot source

The following table describes the fields for Add boot source to template window. This window displays when you click Add Source for a virtual machine template in the Templates tab.

Marking virtual machine templates as favorites

For easier access to virtual machine templates that are used frequently, you can mark those templates as favorites.

Procedure

1. In the OKD Virtualization console, click Workloads → Virtualization from the side menu.

2. Click the Templates tab.

3. Identify the Red Hat template that you want to mark as a favorite.

4. Click the Options menu and select Favorite template. The template moves up higher in the list of displayed templates.

Filtering the list of virtual machine templates by providers

In the Templates tab, you can use the Search by name field to search for virtual machine templates by specifying either the name of the template or a label that identfies the template. You can also filter templates by the provider, and display only those templates that meet your filtering criteria.

Procedure

1. In the OKD Virtualization console, click Workloads → Virtualization from the side menu.

2. Click the Templates tab.

3. To filter templates, click Filter.

4. Select the appropriate checkbox from the list to filter the templates: Red Hat Supported, User Supported, Red Hat Provided, and User Provided.

Creating a virtual machine template with the wizard in the web console

The web console features the Create Virtual Machine Template 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 Create Virtual Machine Template wizard prevents you from moving to the next step until you provide values in the required fields.

Procedure

1. In the OKD Virtualization console, click Workloads → Virtualization from the side menu.

2. Click the Templates tab.

3. Click Create and select Template with Wizard.

4. Fill in all required fields in the General step.

5. Click Next to progress to the Networking step. 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 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 step.

7. Click Add Disk to add a disk, and complete your selections for the fields in the Add Disk screen.

   If Import via URL (creates PVC), Import via Registry (creates PVC), or Container (ephemeral) is selected as Source, a rootdisk disk is created and attached to the virtual machine as the Bootable Disk. 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. Blank disks, PVC disks without a valid boot source, and the cloudinitdisk cannot be used as a boot source.

8. Optional: Click Advanced to configure cloud-init and SSH access.

   Statically inject an SSH key by using the custom script in cloud-init or in the wizard. This allows you to securely and remotely manage virtual machines and manage and transfer information. This step is strongly recommended to secure your VM.

9. Click Review to review and confirm your settings.

10. Click Create Virtual Machine template.

11. Click See virtual machine template details to view details about the virtual machine template.

The template is also listed in the Templates tab.

Virtual machine template wizard fields

The following tables describe the fields for the General, Networking, Storage, and Advanced steps in the Create Virtual Machine Template wizard.

Virtual machine template wizard fields

Networking fields

Storage fields

Advanced storage settings

Cloud-init fields

Additional resources

• Configuring the SR-IOV Network Operator

• Creating and using boot sources

• Customizing the storage profile