Kubernetes - Pod pending: pod has unbound immediate PersistentVolumeClaims

scnzzh@zubt1:~/registry/base$ kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
kube-registry-v1-56d5fbc984-26n5x   0/2     Pending   0          31m
scnzzh@zubt1:~/registry/base$ kubectl describe pod kube-registry-v1-56d5fbc984-26n5x
Name:           kube-registry-v1-56d5fbc984-26n5x
Namespace:      default
Priority:       0
Node:           <none>
Labels:         app=kube-registry
                pod-template-hash=56d5fbc984
Annotations:    <none>
Status:         Pending
IP:             
IPs:            <none>
Controlled By:  ReplicaSet/kube-registry-v1-56d5fbc984
Containers:
  registry:
    Image:        registry:2
    Port:         5000/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:
      /var/lib/registry from registry-storage (rw)
      /var/run/docker.sock from docker (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-kdsjh (ro)
  registryui:
    Image:      hyper/docker-registry-web:latest
    Port:       8080/TCP
    Host Port:  0/TCP
    Environment:
      REGISTRY_URL:   http://localhost:5000/v2
      REGISTRY_NAME:  cluster-registry
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-kdsjh (ro)
Conditions:
  Type           Status
  PodScheduled   False 
Volumes:
  docker:
    Type:          HostPath (bare host directory volume)
    Path:          /var/run/docker.sock
    HostPathType:  
  registry-storage:
    Type:       PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:  registry-pvc
    ReadOnly:   false
  default-token-kdsjh:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-kdsjh
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason            Age   From               Message
  ----     ------            ----  ----               -------
  Warning  FailedScheduling  31m   default-scheduler  0/5 nodes are available: 5 pod has unbound immediate PersistentVolumeClaims.
  Warning  FailedScheduling  31m   default-scheduler  0/5 nodes are available: 5 pod has unbound immediate PersistentVolumeClaims.
scnzzh@zubt1:~/registry/base$ kubectl get pvc
NAME           STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
registry-pvc   Pending                                                     35m

This is because there's no persistent volume in this k8s cluster.