openstack overcloud backup --db-only - unrecognized arguments: --db-only

Issue

• We're trying to backup undercloud and control plane nodes based on OSP16.2 Backing up and restoring the undercloud and control plane nodes but when we try the following commands:

openstack undercloud backup --db-only
openstack overcloud backup --db-only

they fail with the following error:

$ openstack overcloud backup --db-only
usage: openstack overcloud backup [--init [INIT]] [--setup-nfs] [--setup-rear]
                                  [--inventory INVENTORY]
                                  [--storage-ip STORAGE_IP]
                                  [--extra-vars EXTRA_VARS]
openstack overcloud backup: error: unrecognized arguments: --db-only
$ openstack undercloud backup --db-only
usage: openstack undercloud backup [--init [INIT]] [--setup-nfs]
                                   [--setup-rear] [--inventory INVENTORY]
                                   [--add-path ADD_PATH]
                                   [--exclude-path EXCLUDE_PATH]
                                   [--extra-vars EXTRA_VARS]
openstack undercloud backup: error: unrecognized arguments: --db-only

• We have the following versions:

$ openstack --version
openstack 4.0.2
$ cat /etc/redhat-release 
Red Hat Enterprise Linux release 8.4 (Ootpa)

• Based on documentation this should work, what are we doing wrong?