Let's perform the following steps to create a new storage class to consume StoragePool, which we created previously in the Creating storage pools recipe:

1. Create an OpenEBS cStor storage class using the cStor StoragePoolClaim name, cstor-disk-pool, with three replicas:

$ cat <<EOF | kubectl apply -f -
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: openebs-cstor-default
  annotations:
    openebs.io/cas-type: cstor
    cas.openebs.io/config: |
      - name: StoragePoolClaim
        value: "cstor-disk-pool"
      - name: ReplicaCount
        value: "3"
provisioner: openebs.io/provisioner-iscsi
EOF

2. List the storage classes:

$ kubectl get sc
NAME                  PROVISIONER                  AGE
default               kubernetes.io/aws-ebs        25m
gp2 (default)         kubernetes.io/aws-ebs        25m
openebs-cstor-default openebs.io/provisioner-iscsi 6s
openebs-device        openebs.io/local             20m
openebs-hostpath      openebs.io/local             20m
openebs-jiva-default  openebs.io/provisioner-iscsi 20m
openebs-snapshot-promoter volumesnapshot.external-storage.k8s.io/snapshot-promoter 20m
ubun

3. Set the gp2 AWS EBS storage class as the non-default option:

$ kubectl patch storageclass gp2 -p '{"metadata": {"annotations":{"storageclass.beta.kubernetes.io/is-default-class":"false"}}}'

4. Define openebs-cstor-default as the default storage class:

$ kubectl patch storageclass openebs-cstor-default -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'

Make sure that the previous storage class is no longer set as the default and that you only have one default storage class.