Status and Releases
|Status||Min k8s Version||Max k8s version||external-provisioner Version|
A Clone is defined as a duplicate of an existing Kubernetes Volume. For more information on cloning in Kubernetes see the concepts doc for Volume Cloning. A storage provider that allows volume cloning as a create feature, may choose to implement volume cloning via a control-plan CSI RPC call.
For details regarding the kuberentes API for volume cloning, please see kubernetes concepts.
Implementing Volume cloning functionality
To implement volume cloning the CSI driver MUST:
- Implement checks for
csi.CreateVolumeRequest.VolumeContentSourcein the plugin's
It is the responsibility of the storage plugin to either implement an expansion after clone if a provision request size is greater than the source, or allow the external-resizer to handle it. In the case that the plugin does not support resize capability and it does not have the capability to create a clone that is greater in size than the specified source volume, then the provision request should result in a failure.
Deploying volume clone functionality
The Kubernetes CSI development team maintains the external-provisioner which is responsible for detecting requests for a PVC DataSource and providing that information to the plugin via the
csi.CreateVolumeRequest. It's up to the plugin to check the
csi.CreateVolumeRequest for a
VolumeContentSource entry in the CreateVolumeRequest object.
There are no additional side-cars or add on components required.
Enabling Cloning for CSI volumes in Kubernetes
In Kubernetes 1.15 this feature was alpha status and required enabling the appropriate feature gate:
A trivial example implementation can be found in the csi-hostpath plugin in its implementation of