On Prem/Bare Metal. Notebooks are lost when server is shut down/culled?

Hi,
I’m running Z2JH on a single bare metal machine using microk8s. When I stop the server, I lose my notebooks. How can I avoid that? These are my settings(what I thought was relevant to this issue)

template = '''
hub:  
  db:
    url: postgres+psycopg2://{db_user}:{db_password}@{db_host}:{db_port}/{db_database}
    type: postgres
    password: {db_password}
 
 
  cookieSecret: abac
  service:
    type: NodePort
    ports:
      nodePort: 30101 
  
proxy:
  service:
    type: NodePort
    nodePorts:
      http: 30100


  secretToken: "df3445bd70af4cd0e5f534ef5bc993f53da3537a0f8c6d418c00ca313e257172"


singleuser:
  image:
    name: {registry_url}fifteenrock/fifteenrock-jupyterhub
    tag: {tag}
    imagePullPolicy: Always
  cloudMetadata:
    enabled: true
  storage:
    type: postgres         

'''