vsphereVolume manual reattach

README.md

Using Pre-Existing Persistent Disks as PersistentVolumes

This explains how to create a PersistentVolume using existing (vsphereVolume) persistent disks populated with data, and how to use the PersistentVolume in a Pod.

Create Nginx Pod With PV

Create a storage class in the nginx namespace, here we're using the obsolete in-tree VCP provisioner:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: vcp-storage
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: kubernetes.io/vsphere-volume
parameters:
  diskformat: thin

Create a PersistentVolumeClaim in the nginx namespace

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: nginx-claim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi

Create an Nginx pod that mounts the volume at /usr/share/nginx/html in the nginx namespace

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pv-pod
spec:
  volumes:
    - name: nginx-pv-storage
      persistentVolumeClaim:
        claimName: nginx-claim
  containers:
    - name: nginx-pv-container
      image: nginx
      ports:
        - containerPort: 80
          name: "http-server"
      volumeMounts:
        - mountPath: "/usr/share/nginx/html"
          name: nginx-pv-storage

Exec into the container and create an index.html with some custom content:

kubectl exec -it nginx-pv-pod -n nginx -- /bin/bash -c "echo 'Hello from Kubernetes storage' > /usr/share/nginx/html/index.html"

Validate we see the new content by forwarding the pod port and curling the local port:

kubectl port-forward nginx-pv-pod -n nginx 8999:80
curl http://localhost:8999

Mount the Disk at a New Location in vSphere

Find the name of the PVC, specifically note the VOLUME:

kubectl get pvc -n nginx

NAME          STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
nginx-claim   Bound    pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d   2Gi        RWO            vcp-storage    38m

Kill the pod so that the disk becomes unlocked in vSphere allowing us to move it. We should also delete the PV and PCV so we can recreate them to point at the new disk. Grab the PV name from the PVC VOLUME output above.

kubectl delete pod nginx-pv-pod -n nginx
kubectl delete pvc nginx-claim -n nginx

Find the disk in the vSphere datastore explorer using the VOLUME name. The disk will be in the kubevols folder and be named something like pvc-cluster-dynamic-pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d.vmdk.

Let's create a new folder named kubevols-moved in the vSphere datastore explorer and move the PV disk to this new folder. Once moved note the vmdk's new path, it'll be something like [vsanDatastore] 3d085c64-a0e0-7e18-c0c8-bc97e1d34160/pvc-cluster-dynamic-pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d.vmdk.

Let's use that new path and create a new static PV from it.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d
spec:
  accessModes:
  - ReadWriteOnce
  capacity:
    storage: 2Gi
  claimRef:
    kind: PersistentVolumeClaim
    name: nginx-claim
    namespace: nginx
  persistentVolumeReclaimPolicy: Delete
  storageClassName: vcp-storage
  volumeMode: Filesystem
  vsphereVolume:
    fsType: ext4
    volumePath: '[vsanDatastore] 3d085c64-a0e0-7e18-c0c8-bc97e1d34160/pvc-cluster-dynamic-pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d.vmdk'

Replace the volumePath in the above template with your new path from vSphere. Create the PV. Create the PVC.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  namespace: nginx
  name: nginx-claim
spec:
  storageClassName: vcp-storage
  volumeName: pvc-9543dc75-859e-4b87-85e1-a8d77e047d7d
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi

Recreate the nginx-pv-pod using the same yaml as before. Finally validate we see the same content "Hello from Kubernetes storage" by forwarding the pod port and curling the local port:

kubectl port-forward nginx-pv-pod -n nginx 8999:80
curl http://localhost:8999