以下在rook-ceph 1.4.2下实现

• 1、storageclass 设置 allowVolumeExpansion: true

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
   name: rook-ceph-block
provisioner: ceph.rook.io/block
reclaimPolicy: Retain
allowVolumeExpansion: true
parameters:
  blockPool: replicapool
  clusterNamespace: rook-ceph
  fstype: xfs

• 2、编辑pvc增大容量 resources.requests.storage: 5G

kubectl edit -n base pvc minio
...
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: rook-ceph-block
  volumeMode: Filesystem
  volumeName: pvc-e39e8eed-391a-4357-ad33-8c7d87d3d305
...

3、扩展rdb

或者：

#进入toolbox
kubectl exec -it -n rook-ceph rook-ceph-tools-85b7cdfff8-wtd6s -- bash
#用rdb resize命令  size单位为MB
rbd resize --size 8192 --pool replicapool pvc-e39e8eed-391a-4357-ad33-8c7d87d3d305 
扩展好后查看：
rbd info --pool  replicapool pvc-e39e8eed-391a-4357-ad33-8c7d87d3d305 

4、进入pod所在的主机

xfs存储 : xfs_growfs /dev/rbd1
ext存储: resize2fs /dev/rbd1

5、进入pod，查看是否容量扩大

kubectl exec -it -n base minio-664758d447-hx9kk -- sh
df -ah

6、遗留问题，PVC容量显示不正确