08-Persistent-Volume-Claims.md

Persistent Volume Claims

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In this section, we will take a look at Persistent Volume Claim

• Now we will create a Persistent Volume Claim to make the storage available to the node.
• Volumes and Persistent Volume Claim are two separate objects in the Kubernetes namespace.
• Once the Persistent Volume Claim created, Kubernetes binds the Persistent Volumes to claim based on the request and properties set on the volume.

• If properties not matches or Persistent Volume is not available for the Persistent Volume Claim then it will display the pending state.

pvc-definition.yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: myclaim
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
   requests:
     storage: 1Gi

pv-definition.yaml

kind: PersistentVolume
apiVersion: v1
metadata:
    name: pv-vol1
spec:
    accessModes: [ "ReadWriteOnce" ]
    capacity:
     storage: 1Gi
    hostPath:
     path: /tmp/data

Create the Persistent Volume

$ kubectl create -f pv-definition.yaml
persistentvolume/pv-vol1 created

$ kubectl get pv
NAME      CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
pv-vol1   1Gi        RWO            Retain           Available                                   10s

Create the Persistent Volume Claim

$ kubectl create -f pvc-definition.yaml
persistentvolumeclaim/myclaim created

$ kubectl get pvc
NAME      STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
myclaim   Pending                                                     35s

$ kubectl get pvc
NAME      STATUS   VOLUME    CAPACITY   ACCESS MODES   STORAGECLASS   AGE
myclaim   Bound    pv-vol1   1Gi        RWO                           1min

Delete the Persistent Volume Claim

$ kubectl delete pvc myclaim

Delete the Persistent Volume

$ kubectl delete pv pv-vol1

Kubernetes Persistent Volume Claims Reference Docs

• https://kubernetes.io/docs/concepts/storage/persistent-volumes/#persistentvolumeclaims
• https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.18/#persistentvolumeclaim-v1-core
• https://docs.cloud.oracle.com/en-us/iaas/Content/ContEng/Tasks/contengcreatingpersistentvolumeclaim.htm