Scenario

An application requires persistent storage that can be resized without downtime.

Task

Create a StorageClass, PVC, and Pod. Once the pod is running, expand the PVC to the expanded size without restarting the pod.

Template files are available at /home/interview/.

Step 1: Edit StorageClass template sc.yaml to enable volume expansion

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: expandable-sc                         # Fix name
provisioner: rancher.io/local-path
allowVolumeExpansion: true                    # Fix: false -> true
volumeBindingMode: WaitForFirstConsumer

kubectl apply -f /home/interview/sc.yaml

Step 2: Edit PVC template pvc.yaml with correct values

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-pvc                          # Fix name
  namespace: storage                      # Fix namespace
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: expandable-sc         # Fix storageClassName
  resources:
    requests:
      storage: 1Gi                        # Fix size

kubectl apply -f /home/interview/pvc.yaml

Step 3: Edit pod template pod.yaml to mount the PVC

apiVersion: v1
kind: Pod
metadata:
  name: app-pod                           # Fix name
  namespace: storage                      # Fix namespace
spec:
  containers:
    - name: app
      image: nginx
      volumeMounts:
        - name: data                      # Fix name
          mountPath: /data                # Fix path
  volumes:
    - name: data                          # Fix name
      persistentVolumeClaim:              # Fix: emptyDir -> persistentVolumeClaim
        claimName: data-pvc               # Add

kubectl apply -f /home/interview/pod.yaml

Step 4: Expand PVC to 5Gi (without restarting pod)

kubectl edit pvc data-pvc -n storage

Change spec.resources.requests.storage from 1Gi to 5Gi:

spec:
  resources:
    requests:
      storage: 5Gi    # Change from 1Gi to 5Gi

Step 5: Verify expansion

kubectl get pvc data-pvc -n storage