Merge "Improve documentations for NovaLibvirtFileBackedMemory" into stable/train

deployment/nova/nova-compute-container-puppet.yaml

@@ -272,7 +272,9 @@ parameters:
       - role_specific
   NovaLibvirtFileBackedMemory:
     description: >
-      Available capacity in MiB for file-backed memory.
+      Available capacity in MiB for file-backed memory. When configured, the
+      ``NovaRAMAllocationRatio`` and ``NovaReservedHostMemory`` parameters must
+      be set to 0.
     default: 0
     type: number
     tags: