diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index f97957f0feb9a37e9075c2a3c8314ee0b06395ba..26ea707538b7e8b17db40968568f9d48fb5c0a4e 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -6711,6 +6711,8 @@ class IAllocator(object):
         "disk_template": iinfo.disk_template,
         "hypervisor": iinfo.hypervisor,
         }
+      pir["disk_space_total"] = _ComputeDiskSize(iinfo.disk_template,
+                                                 pir["disks"])
       instance_data[iinfo.name] = pir
 
     data["instances"] = instance_data