#Generic ephemeral volumes

Generic Ephemeral Volumes in Kubernetes are a feature that allows you to provision ephemeral (temporary), per-pod volumes using existing StorageClasses and CSI drivers, without needing to predefine PersistentVolumeClaims (PVCs).

They combine the flexibility of dynamic provisioning with the simplicity of pod-level volume declaration.

• They are temporary volumes that are automatically:

  • created when the Pod starts

  • deleted when the Pod terminates

• Use the same underlying mechanisms as PersistentVolumeClaim

• Require a CSI (Container Storage Interface) driver that supports dynamic provisioning

#Example ephemeral volumes

This automatically creates a temporary PVC for the Pod using the specified StorageClass.

apiVersion: v1
kind: Pod
metadata:
  name: ephemeral-demo
spec:
  containers:
    - name: app
      image: busybox
      command: ["sh", "-c", "echo hello > /data/hello.txt && sleep 3600"]
      volumeMounts:
        - mountPath: /data
          name: ephemeral-volume
  volumes:
    - name: ephemeral-volume
      ephemeral:
        volumeClaimTemplate:
          metadata:
            labels:
              type: temporary
          spec:
            accessModes: [ "ReadWriteOnce" ]
            resources:
              requests:
                storage: 1Gi
            storageClassName: standard

#Key features

#When to Use Generic Ephemeral Volumes

• When you need temporary storage with features like:

  • Resizable volumes

  • Snapshots

  • Encryption

  • Non-node-local storage (e.g., cloud block storage)

• Ideal for:

  • Caching intermediate data

  • Temporary working directories

  • Pipelines, AI/ML workflows

#How Are They Different from emptyDir?