What to do with Released persistent volume?

Question

TL;DR. I'm lost as to how to access the data after deleting a PVC, as well as why PV wouldn't go away after deleting a PVC.

Steps I'm taking:

1. created a disk in GCE manually:

   gcloud compute disks create --size 5Gi disk-for-rabbitmq --zone europe-west1-b
   

2. ran:

   kubectl apply -f /tmp/pv-and-pvc.yaml
   

   with the following config:

   # /tmp/pv-and-pvc.yaml
   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: pv-for-rabbitmq
   spec:
     accessModes:
     - ReadWriteOnce
     capacity:
       storage: 5Gi
     gcePersistentDisk:
       fsType: ext4
       pdName: disk-for-rabbitmq
     persistentVolumeReclaimPolicy: Delete
     storageClassName: standard
   ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: pvc-for-rabbitmq
   spec:
     accessModes:
     - ReadWriteOnce
     resources:
       requests:
         storage: 5Gi
     storageClassName: standard
     volumeName: pv-for-rabbitmq
   

3. deleted a PVC manually (on a high level: I'm simulating a disastrous scenario here, like accidental deletion or misconfiguration of a helm release):

   kubectl delete pvc pvc-for-rabbitmq
   

At this point I see the following:

$ kubectl get pv
NAME              CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS     CLAIM                      STORAGECLASS   REASON   AGE
pv-for-rabbitmq   5Gi        RWO            Delete           Released   staging/pvc-for-rabbitmq   standard                8m
$

A side question, just improve my understanding: why PV is still there, even though it has a reclaim policy set to Delete? Isn't this what the docs say for the Delete reclaim policy?

Now if I try to re-create the PVC to regain access to the data in PV:

$ kubectl apply -f /tmp/pv-and-pvc.yaml
persistentvolume "pv-for-rabbitmq" configured
persistentvolumeclaim "pvc-for-rabbitmq" created
$

I still get this for pvs, e.g. a PV is stuck in Released state:

$
kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS     CLAIM                             STORAGECLASS   REASON    AGE
pv-for-rabbitmq                            5Gi        RWO            Delete           Released   staging/pvc-for-rabbitmq          standard                 15m
$

...and I get this for pvcs:

$
kubectl get pvc
NAME               STATUS    VOLUME            CAPACITY   ACCESS MODES   STORAGECLASS   AGE
pvc-for-rabbitmq   Pending   pv-for-rabbitmq   0                         standard       1m
$

Looks like my PV is stuck in Released status, and PVC cannot access the PV which is not in Available status.

So, why the same PV and PVC cannot be friends again? How do I make a PVC to regain access to data in the existing PV?

Answer 1

kubectl patch pv pv-for-rabbitmq -p '{"spec":{"claimRef": null}}'

This worked for me.