Storage

Get default StorageClass name

oc get sc -o jsonpath='{.items[?(@.metadata.annotations.storageclass\.kubernetes\.io/is-default-class=="true")].metadata.name}'

Unbound an existing pvc from one pod to be used by another pod and retaining data

1. Scale pods to 0

   oc scale --replicas=0 deployment/victoria
   

2. Edit deployment and delete volumes that make a reference to pvc

   oc edit deployment/victoria
   
   apiVersion: apps/v1
   kind: Deployment
   metadata:
   annotations:
   deployment.kubernetes.io/revision: "7"
   kubectl.kubernetes.io/last-applied-configuration: |
   ...
   spec:
     containers:
     - args:
       - -selfScrapeInterval=10s
       - -dedup.minScrapeInterval=60s
       image: victoriametrics/victoria-metrics
       imagePullPolicy: Always
       name: victoria
       ports:
       - containerPort: 8428
         protocol: TCP
       resources: {}
       terminationMessagePath: /dev/termination-log
       terminationMessagePolicy: File
       volumeMounts:
       - mountPath: /victoria-metrics-data
         name: victoria-data
     dnsPolicy: ClusterFirst
     restartPolicy: Always
     schedulerName: default-scheduler
     securityContext: {}
     terminationGracePeriodSeconds: 30
     volumes:
     - name: victoria-data
       persistentVolumeClaim:
         claimName: pvc-victoria-data2
   

3. Remove claimRef to pvc on pv and make sure persistentVolumeReclaimPolicy: Retain

   oc edit pv/pv-victoria-data
   
   apiVersion: v1
   kind: PersistentVolume
   metadata:
   annotations:
   kubectl.kubernetes.io/last-applied-configuration: |
   ...
   spec:
   accessModes:
   - ReadWriteMany
   capacity:
   storage: 10Gi
   claimRef:
   apiVersion: v1
   kind: PersistentVolumeClaim
   name: pvc-victoria-data2
   namespace: victoria
   resourceVersion: "33452972"
   uid: 9d4fb2ac-b09d-4110-b337-1d93a34279f7
   nfs:
   path: /export/data
   server: helper.ocp4.info.net
   persistentVolumeReclaimPolicy: Retain
   volumeMode: Filesystem
   status:
   phase: Bound
   

4. Make sure PV is available

   oc get pv
   
   NAME               CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
   pv-victoria-data   10Gi       RWX            Retain           Available  
   

At this point PV is ready to be used by another pod