创建pvc，创建完成后是pending状态，等有dp、pod调用后就会变成bound状态
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: grafana-data
namespace: monitoring
labels:
app: grafana
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 4Gi
storageClassName: gp2
volumeMode: Filesystem
申明volumes，类型就是pvc。这时在公有云的存储卷管理里就能看到这个设备
volumes:
- name: grafana-storage
persistentVolumeClaim:
claimName: grafana-data