Create a KubeVirt VM Using a Precreated PVC

You can create a KubeVirt virtual machine (VM) that references an existing PersistentVolumeClaim (PVC). This workflow lets you provision and verify storage before creating the VM, reuse a PVC across VM definitions, or manage the PVC lifecycle independently of the VM.

When you reference a Fusion-backed PVC in a VM, the Portworx Fusion Controller detects the reference, creates a corresponding FusionWorkload custom resource (CR) to track the VM storage, and provisions the volume on the appropriate FlashArray based on the associated Fusion preset.

note

This workflow supplements the DataVolumeTemplate workflow described in Create a KubeVirt VM Using a Fusion Preset. Existing VMs that use DataVolumeTemplate continue to work without changes.

Prerequisites

Before you begin, ensure that the following requirements are met:

• Portworx Fusion Controller is enabled. For more information, see Enable Portworx Fusion Controller.
• A Fusion preset is available. For more information, see Create a Fusion Preset.

PVC compatibility requirements

Before referencing a PVC in a VM, ensure that the PVC meets the following requirements:

Requirement	Description
StorageClass	The PVC must use the same StorageClass as the VM's existing PVCs.
Access mode	The access mode matches the disk usage. Use ReadWriteOnce (RWO) for a single-node disk or ReadWriteMany (RWX) for disks on VMs that use live migration.
Volume mode	The volume mode matches the VM disk requirements. Use Block for raw block disks or Filesystem for file system-backed disks.
Status	The PVC is in the Pending state before the VM references it.
Namespace	The PVC and VM are in the same namespace.

important

A KubeVirt VM must use a single RWX volume type for all its disks. Do not mix volume types on the same VM. Mixing volume types can cause node drains to stall during OpenShift Container Platform or Portworx upgrades.

Create a VM using a precreated PVC

To create a VM that uses an existing PVC as a disk:

1. Create a PVC that references a Fusion-backed StorageClass:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: fusion-vm-disk
     namespace: portworx
   spec:
     storageClassName: fleet-testing-gold-tier
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 50Gi

   Replace fleet-testing-gold-tier with the StorageClass generated from your Fusion preset.

2. Apply the PVC:

   kubectl apply -f fusion-vm-disk.yaml

3. Create the VM and reference the PVC as a disk by using a persistentVolumeClaim volume source:

   apiVersion: kubevirt.io/v1
   kind: VirtualMachine
   metadata:
     name: fusion-vm
     namespace: portworx
   spec:
     running: true
     template:
       spec:
         domain:
           devices:
             disks:
               - name: os-disk
                 disk:
                   bus: virtio
         volumes:
           - name: os-disk
             persistentVolumeClaim:
               claimName: fusion-vm-disk

4. Apply the VM:

   kubectl apply -f fusion-vm.yaml

5. Verify that the PVC is in the Bound state:

   kubectl get pvc fusion-vm-disk -n portworx

   Verify that the STATUS column shows Bound:

   NAME             STATUS   VOLUME         CAPACITY   ACCESS MODES   STORAGECLASS              AGE
   fusion-vm-disk   Bound    pvc-a1b2c3d4   50Gi       RWO            fleet-testing-gold-tier   30s

6. Verify that the VM is running:

   kubectl get vm fusion-vm -n portworx

   Verify that the STATUS column shows Running.

Verify the Fusion workload

When the Fusion Controller detects the PVC reference, it creates a FusionWorkload CR to represent and track the VM storage.

To list the Fusion workloads, run:

kubectl get fusionworkload -n <namespace>

To view provisioning details and events for the workload, run:

kubectl describe fusionworkload <workload-name> -n <namespace>

Replace <namespace> with the namespace where the VM and PVC reside and <workload-name> with the name of the FusionWorkload CR associated with the VM.

If provisioning fails, the VM remains in the Provisioning state. Check the events for the corresponding FusionWorkload CR to determine the cause.

note

The PVC has an independent lifecycle from the VM. Deleting the VM does not delete a precreated PVC. Delete the PVC separately when you no longer need the storage.