Creating Instance Types and Preferences by using virtctl

As of KubeVirt v1.0, you can use virtctl subcommands to create instance types and preferences.

Creating Instance Types

The virtctl subcommand create instancetype allows easy creation of an instance type manifest from the command line. The command also provides several flags that can be used to create your desired manifest.

There are two required flags that need to be specified:

1. --cpu: the number of vCPUs to be requested
2. --memory: the amount of memory to be requested

Additionally, there are several optional flags that can be used, such as specifying a list of GPUs for passthrough, choosing the desired IOThreadsPolicy, or simply providing the name of our instance type.

By default, the command creates cluster-wide instance types. If the user wants to create the namespaced version, they need to provide the namespaced flag. The namespace name can be specified by using the --namespace flag.

For a complete list of flags and their descriptions, use the following command:

virtctl create instancetype -h

Examples

Create a manifest for a VirtualMachineClusterInstancetype with the required --cpu and --memory flags:

virtctl create instancetype --cpu 2 --memory 256Mi

Create a manifest for a VirtualMachineInstancetype with a specified namespace:

virtctl create instancetype --cpu 2 --memory 256Mi --namespace my-namespace

Create a manifest for a VirtualMachineInstancetype without a specified namespace name:

virtctl create instancetype --cpu 2 --memory 256Mi --namespaced

Creating Preferences

The virtctl subcommand create preference allows easy creation of a preference manifest from the command line. This command serves as a starting point to create the basic structure of a preference manifest, as it does not allow specifying all the options that are supported in preferences.

The current set of flags allows us, for example, to specify the preferred CPU topology, machine type or a storage class.

By default, the command creates cluster-wide preferences. If the user wants to create the namespaced version, they need to provide the namespaced flag. The namespace name can be specified by using the --namespace flag.

For a complete list of flags and their descriptions, use the following command:

virtctl create preference -h

Examples

Create a manifest for a VirtualMachineClusterPreference with a preferred CPU topology:

virtctl create preference --cpu-topology preferSockets

Create a manifest for a VirtualMachinePreference with a specified namespace:

virtctl create preference --namespace my-namespace

Create a manifest for a VirtualMachinePreference with the preferred storage class:

virtctl create preference --namespaced --volume-storage-class my-storage