diff --git a/README.rst b/README.rst
index 7ea6da8..0943db2 100644
--- a/README.rst
+++ b/README.rst
@@ -298,6 +298,15 @@
           # Add key without value to remove line from policy.json
           'compute:create:attach_network':
 
+Configure host_subset_size
+--------------------------
+
+.. code-block:: yaml
+
+    nova:
+      controller:
+        host_subset_size: 1
+
 
 Compute nodes
 -------------