diff --git a/environments/low-memory-usage.yaml b/environments/low-memory-usage.yaml
index b02be52610..a4d3d9296a 100644
--- a/environments/low-memory-usage.yaml
+++ b/environments/low-memory-usage.yaml
@@ -23,3 +23,5 @@ parameter_defaults:
   CephPoolDefaultPgNum: 16
   ManilaCephFSDataPoolPGNum: 16
   ManilaCephFSMetadataPoolPGNum: 16
+
+  NovaReservedHostMemory: 512