Cloning a virtual machine disk into a new data volume

• Prerequisites
• About data volumes
• Cloning the persistent volume claim of a virtual machine disk into a new data volume
• Template: Data volume clone configuration file
• CDI supported operations matrix

You can clone the persistent volume claim (PVC) of a virtual machine disk into a new data volume by referencing the source PVC in your data volume configuration file.

Prerequisites

• Users need additional permissions to clone the PVC of a virtual machine disk into another namespace.

About data volumes

DataVolume objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). Data volumes are integrated with OKD Virtualization, and they prevent a virtual machine from being started before the PVC has been prepared.

Cloning the persistent volume claim of a virtual machine disk into a new data volume

You can clone a persistent volume claim (PVC) of an existing virtual machine disk into a new data volume. The new data volume can then be used for a new virtual machine.

Prerequisites

• Determine the PVC of an existing virtual machine disk to use. You must power down the virtual machine that is associated with the PVC before you can clone it.

• Install the OpenShift CLI (oc).

Procedure

1. Examine the virtual machine disk you want to clone to identify the name and namespace of the associated PVC.

2. Create a YAML file for a data volume that specifies the name of the new data volume, the name and namespace of the source PVC, and the size of the new data volume.

   For example:

   apiVersion: cdi.kubevirt.io/v1beta1
   kind: DataVolume
   metadata:
     name: <cloner-datavolume> (1)
   spec:
     source:
       pvc:
         namespace: "<source-namespace>" (2)
         name: "<my-favorite-vm-disk>" (3)
     pvc:
       accessModes:
         - ReadWriteOnce
       resources:
         requests:
           storage: <2Gi> (4)

   1	The name of the new data volume.
   2	The namespace where the source PVC exists.
   3	The name of the source PVC.
   4	The size of the new data volume. You must allocate enough space, or the cloning operation fails. The size must be the same as or larger than the source PVC.

3. Start cloning the PVC by creating the data volume:

   $ oc create -f <cloner-datavolume>.yaml

   Data volumes prevent a virtual machine from starting before the PVC is prepared, so you can create a virtual machine that references the new data volume while the PVC clones.

Template: Data volume clone configuration file

example-clone-dv.yaml

apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
metadata:
  name: "example-clone-dv"
spec:
  source:
      pvc:
        name: source-pvc
        namespace: example-ns
  pvc:
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: "1G"

CDI supported operations matrix

This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.

✓ Supported operation

□ Unsupported operation

* Requires scratch space

** Requires scratch space if a custom certificate authority is required