@@ -3313,13 +3313,21 @@ def _show_progress(progress):
         server = utils.find_resource(
             compute_client.servers, parsed_args.server)
 
-        # If parsed_args.image is not set, default to the currently used one.
+        # If parsed_args.image is not set and if the instance is image backed,
+        # default to the currently used one. If the instance is volume backed,
+        # it is not trivial to fetch the current image and probably better
+        # to error out in this case and ask user to supply the image.
         if parsed_args.image:
             image = image_client.find_image(
                 parsed_args.image, ignore_missing=False)
         else:
-            image_id = server.to_dict().get('image', {}).get('id')
-            image = image_client.get_image(image_id)
+            if not server.image:
+                msg = _(
+                    'The --image option is required when rebuilding a '
+                    'volume-backed server'
+                )
+                raise exceptions.CommandError(msg)
+            image = image_client.get_image(server.image['id'])
 
         kwargs = {}
 
 
@@ -5860,6 +5860,25 @@ def test_rebuild_with_current_image(self):
         self.get_image_mock.assert_called_with(self.image.id)
         self.server.rebuild.assert_called_with(self.image, None)
 
+    def test_rebuild_with_volume_backed_server_no_image(self):
+        # the volume-backed server will have the image attribute set to an
+        # empty string, not null/None
+        self.server.image = ''
+
+        arglist = [
+            self.server.id,
+        ]
+        verifylist = [
+            ('server', self.server.id),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        exc = self.assertRaises(
+            exceptions.CommandError,
+            self.cmd.take_action,
+            parsed_args)
+        self.assertIn('The --image option is required', str(exc))
+
     def test_rebuild_with_name(self):
         name = 'test-server-xxx'
         arglist = [