Use of Ephemeral volumes

Generic Ephemeral volumes

Generic ephemeral volumes also work with typical storage operations such as snapshotting, cloning, resizing, and storage capacity tracking.

The following steps will allow you to create a generic ephemeral volume with the Portworx CSI Driver.

In this example we are using the px-csi-db storage class out of the box. Please refer CSI Enabled Storage Classes for a list of available CSI enabled storage classes offered by Portworx.

1. Create a pod spec that uses a Portworx CSI Driver StorageClass, declaring the ephemeral volume as seen below in a YAML file named ephemeral-volume-pod.yaml:

   kind: Pod
   apiVersion: v1
   metadata:
     name: my-app
   spec:
     containers:
       - name: my-frontend
         image: busybox
         volumeMounts:
         - mountPath: "/scratch"
           name: scratch-volume
         command: [ "sleep", "1000000" ]
     volumes:
       - name: scratch-volume
         ephemeral:
           volumeClaimTemplate:
             metadata:
               labels:
                 type: my-frontend-volume
             spec:
               accessModes: [ "ReadWriteOnce" ]
               storageClassName: "px-csi-db"
               resources:
                 requests:
                   storage: 1Gi

2. Apply the ephemeral-volume-pod.yaml spec to create the pod with a generic ephemeral volume:

   Kubernetes

   kubectl apply -f ephemeral-volume-pod.yaml

   Openshift

   oc apply -f ephemeral-volume-pod.yaml

note

Ephemeral volumes are automatically deleted when the associated application pod is deleted.

Migration to CSI PVCs

Currently, you cannot migrate or convert PVCs created using the native Kubernetes driver to the CSI driver. However, this is not required, and both types of PVCs can co-exist on the same cluster.