Merge pull request #1725 from dankova22/reuse-doc-update

Clarify limitations of reuseAccessPoint

Author: dankova22

docs/README.md

@@ -38,7 +38,7 @@ The following CSI interfaces are implemented:
 | subPathPattern        |        | `/${.PV.name}`  | true     | The template used to construct the subPath under which each of the access points created under Dynamic Provisioning. Can be made up of fixed strings and limited variables, is akin to the 'subPathPattern' variable on the [nfs-subdir-external-provisioner](https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner) chart. Supports `.PVC.name`,`.PVC.namespace` and `.PV.name` |
 | ensureUniqueDirectory |        | true            | true     | **NOTE: Only set this to false if you're sure this is the behaviour you want**.<br/> Used when dynamic provisioning is enabled, if set to true, appends the a UID to the pattern specified in `subPathPattern` to ensure that access points will not accidentally point at the same directory.                                                                                                |
 | az                    |        | ""              | true     | Used for cross-account mount. `az` under storage class parameter is optional. If specified, mount target associated with the az will be used for cross-account mount. If not specified, a random mount target will be picked for cross account mount                                                                                                                                          |
-| reuseAccessPoint      |        | false           | true     | When set to true, it creates the Access Point client-token from the provided PVC name. So that the AccessPoint can be replicated from a different cluster if same PVC name and storageclass configuration are used.                                                                                                                                                                                    |
+| reuseAccessPoint      |        | false           | true     | When set to true, it creates the Access Point client-token from the provided PVC name. So that the AccessPoint can be replicated from a different cluster if same PVC name and storageclass configuration are used. This feature is currently only supported for a single filesystem per account/region. If attempting to reuse access points across multiple clusters and filesystems within the same region, volume provisioning will fail. If you wish to use the same EFS accesspoint across different clusters for multiple filesystems in a single region, we recommend manually creating the access points and [statically provisioning](https://github.com/kubernetes-sigs/aws-efs-csi-driver/tree/master/examples/kubernetes/access_points) those volumes.                                                                                                                                                                            |
 
 **Note**
 * Custom Posix group Id range for Access Point root directory must include both `gidRangeStart` and `gidRangeEnd` parameters. These parameters are optional only if both are omitted. If you specify one, the other becomes mandatory.