Update driver-parameters.md

Author: andyzhangx

docs/driver-parameters.md

@@ -43,8 +43,8 @@ mountOptions | mount options separated by comma during snapshot creation, e.g. `
  - `${pvc.metadata.namespace}`
  - `${pv.metadata.name}`
 
-#### provide `mountOptions` for `DeleteVolume`
-> since `DeleteVolumeRequest` does not provide `mountOptions`, following is the workaround to provide `mountOptions` for `DeleteVolume`, check details [here](https://github.com/kubernetes-csi/csi-driver-nfs/issues/260)
+#### provide `mountOptions` for `DeleteVolume` and `DeleteSnapshot`
+> since `DeleteVolumeRequest` and `DeleteSnapshotRequest` does not provide `mountOptions`, following is the workaround to provide `mountOptions` for `DeleteVolume` and `DeleteSnapshot`, check details [here](https://github.com/kubernetes-csi/csi-driver-nfs/issues/260)
   - create a secret with `mountOptions`
 ```console
 kubectl create secret generic mount-options --from-literal mountOptions="nfsvers=3,hard"
@@ -67,4 +67,17 @@ volumeBindingMode: Immediate
 allowVolumeExpansion: true
 mountOptions:
   - nfsvers=4.1
+```
+  - define a storage class with `csi.storage.k8s.io/snapshotter-secret-name` and `csi.storage.k8s.io/snapshotter-secret-namespace` setting:
+```yaml
+apiVersion: snapshot.storage.k8s.io/v1
+kind: VolumeSnapshotClass
+metadata:
+  name: csi-nfs-snapclass
+driver: nfs.csi.k8s.io
+deletionPolicy: Delete
+parameters:
+  # csi.storage.k8s.io/provisioner-secret is only needed for providing mountOptions in DeleteSnapshot
+  csi.storage.k8s.io/provisioner-secret-name: "mount-options"
+  csi.storage.k8s.io/provisioner-secret-namespace: "default"
 ```