diff --git a/novaclient/tests/unit/test_utils.py b/novaclient/tests/unit/test_utils.py
index 372e6f007..46ffbc13a 100644
--- a/novaclient/tests/unit/test_utils.py
+++ b/novaclient/tests/unit/test_utils.py
@@ -380,26 +380,6 @@ class ValidationsTestCase(test_utils.TestCase):
                 self.assertIn(key, str(ce))
 
 
-class ResourceManagerExtraKwargsHookTestCase(test_utils.TestCase):
-    def test_get_resource_manager_extra_kwargs_hook_test(self):
-        do_foo = mock.MagicMock()
-
-        def hook1(args):
-            return {'kwarg1': 'v_hook1'}
-
-        def hook2(args):
-            return {'kwarg1': 'v_hook2'}
-        do_foo.resource_manager_kwargs_hooks = [hook1, hook2]
-        args = {}
-        exc = self.assertRaises(exceptions.NoUniqueMatch,
-                                utils.get_resource_manager_extra_kwargs,
-                                do_foo,
-                                args)
-        except_error = ("Hook 'hook2' is attempting to redefine "
-                        "attributes")
-        self.assertIn(except_error, six.text_type(exc))
-
-
 class DoActionOnManyTestCase(test_utils.TestCase):
 
     def _test_do_action_on_many(self, side_effect, fail):
diff --git a/novaclient/utils.py b/novaclient/utils.py
index df4464e6c..8869f696b 100644
--- a/novaclient/utils.py
+++ b/novaclient/utils.py
@@ -118,43 +118,6 @@ def service_type(stype):
     return inner
 
 
-def add_resource_manager_extra_kwargs_hook(f, hook):
-    """Add hook to bind CLI arguments to ResourceManager calls.
-
-    The `do_foo` calls in shell.py will receive CLI args and then in turn pass
-    them through to the ResourceManager. Before passing through the args, the
-    hooks registered here will be called, giving us a chance to add extra
-    kwargs (taken from the command-line) to what's passed to the
-    ResourceManager.
-    """
-    if not hasattr(f, 'resource_manager_kwargs_hooks'):
-        f.resource_manager_kwargs_hooks = []
-
-    names = [h.__name__ for h in f.resource_manager_kwargs_hooks]
-    if hook.__name__ not in names:
-        f.resource_manager_kwargs_hooks.append(hook)
-
-
-def get_resource_manager_extra_kwargs(f, args, allow_conflicts=False):
-    """Return extra_kwargs by calling resource manager kwargs hooks."""
-    hooks = getattr(f, "resource_manager_kwargs_hooks", [])
-    extra_kwargs = {}
-    for hook in hooks:
-        hook_kwargs = hook(args)
-        hook_name = hook.__name__
-        conflicting_keys = set(hook_kwargs.keys()) & set(extra_kwargs.keys())
-        if conflicting_keys and not allow_conflicts:
-            msg = (_("Hook '%(hook_name)s' is attempting to redefine "
-                     "attributes '%(conflicting_keys)s'") %
-                   {'hook_name': hook_name,
-                    'conflicting_keys': conflicting_keys})
-            raise exceptions.NoUniqueMatch(msg)
-
-        extra_kwargs.update(hook_kwargs)
-
-    return extra_kwargs
-
-
 def pretty_choice_list(l):
     return ', '.join("'%s'" % i for i in l)
 
diff --git a/novaclient/v2/shell.py b/novaclient/v2/shell.py
index 7c05d1691..5fcff2df9 100644
--- a/novaclient/v2/shell.py
+++ b/novaclient/v2/shell.py
@@ -877,9 +877,6 @@ def do_boot(cs, args):
     """Boot a new server."""
     boot_args, boot_kwargs = _boot(cs, args)
 
-    extra_boot_kwargs = utils.get_resource_manager_extra_kwargs(do_boot, args)
-    boot_kwargs.update(extra_boot_kwargs)
-
     server = cs.servers.create(*boot_args, **boot_kwargs)
     if boot_kwargs['reservation_id']:
         new_server = {'reservation_id': server}
@@ -1815,13 +1812,11 @@ def do_rebuild(cs, args):
     else:
         _password = None
 
-    kwargs = utils.get_resource_manager_extra_kwargs(do_rebuild, args)
-    kwargs['preserve_ephemeral'] = args.preserve_ephemeral
-    kwargs['name'] = args.name
+    kwargs = {'preserve_ephemeral': args.preserve_ephemeral,
+              'name': args.name,
+              'meta': _meta_parsing(args.meta)}
     if 'description' in args:
         kwargs['description'] = args.description
-    meta = _meta_parsing(args.meta)
-    kwargs['meta'] = meta
 
     # 2.57 deprecates the --file option and adds the --user-data and
     # --user-data-unset options.
@@ -1910,8 +1905,7 @@ def do_resize(cs, args):
     """Resize a server."""
     server = _find_server(cs, args.server)
     flavor = _find_flavor(cs, args.flavor)
-    kwargs = utils.get_resource_manager_extra_kwargs(do_resize, args)
-    server.resize(flavor, **kwargs)
+    server.resize(flavor)
     if args.poll:
         _poll_for_status(cs.servers.get, server.id, 'resizing',
                          ['active', 'verify_resize'])
diff --git a/releasenotes/notes/get-rid-off-redundant-methods-47e679c13e88f28a.yaml b/releasenotes/notes/get-rid-off-redundant-methods-47e679c13e88f28a.yaml
new file mode 100644
index 000000000..954ae395d
--- /dev/null
+++ b/releasenotes/notes/get-rid-off-redundant-methods-47e679c13e88f28a.yaml
@@ -0,0 +1,10 @@
+---
+deprecations:
+  - |
+    ``novaclient.utils.add_resource_manager_extra_kwargs_hook`` and
+    ``novaclient.utils.get_resource_manager_extra_kwargs`` were designed for
+    supporting extensions in nova/novaclient. Nowadays, this "extensions"
+    feature is abandoned and both ``add_resource_manager_extra_kwargs_hook``,
+    ``add_resource_manager_extra_kwargs_hook`` are not used in novaclient's
+    code. These methods are not documented, so we are removing them without
+    standard deprecation cycle.