您是否创建了正确的存储类并将其命名 fast ?
试试这个（应该可以在azure上使用）：

...
  volumeClaimTemplates:
  - metadata:
      name: cassandra-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: fast
      resources:
        requests:
          storage: 1Gi

---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fast
parameters:
  fsType: xfs
  kind: Managed
  storageaccounttype: Premium_LRS
provisioner: kubernetes.io/azure-disk
reclaimPolicy: Delete
volumeBindingMode: Immediate

有状态集需要一个持久卷来存储状态，您提供的文档有一个部分显示它：

volumeClaimTemplates:
  - metadata:
      name: cassandra-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: fast
      resources:
        requests:
          storage: 1Gi
---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: fast
provisioner: k8s.io/minikube-hostpath
parameters:
  type: pd-ssd

这些是根据需要在azure中创建pv和/或存储类的文档
https://docs.microsoft.com/en-us/azure/aks/azure-files-dynamic-pv
然后可以将对象与statefulset相关联