Merge pull request #38786 from mattcary/mig-reg

Detail zonal provisioning for GCE PD

Author: k8s-ci-robot

content/en/docs/concepts/storage/storage-classes.md

@@ -343,7 +343,13 @@ using `allowedTopologies`.
 
 {{< note >}}
 `zone` and `zones` parameters are deprecated and replaced with
-[allowedTopologies](#allowed-topologies)
+[allowedTopologies](#allowed-topologies). When
+[GCE CSI Migration](/docs/concepts/storage/volumes/#gce-csi-migration) is
+enabled, a GCE PD volume can be provisioned in a topology that does not match
+any nodes, but any pod trying to use that volume will fail to schedule. With
+legacy pre-migration GCE PD, in this case an error will be produced
+instead at provisioning time. GCE CSI Migration is enabled by default beginning
+from the Kubernetes 1.23 release.
 {{< /note >}}
 
 ### NFS