---
apiVersion: v1
kind: Namespace
metadata:
  name: lemmy
...
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-lemmy-postgresql-0
  namespace: lemmy
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn-retain
  resources:
    requests:
      storage: 20Gi
...