diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 096ee718a5d3fd0bc7b8340610485e487a587eff..dab9ef728aefba75327a0b1e1fbe51a4ea1378a4 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -5703,6 +5703,7 @@ class LUQueryInstanceData(NoHooksLU):
       "sstatus": dev_sstatus,
       "children": dev_children,
       "mode": dev.mode,
+      "size": dev.size,
       }
 
     return data
diff --git a/scripts/gnt-instance b/scripts/gnt-instance
index a54672c9003f3e59572f8d57f882f3465359f4e0..def14bd7c7d777124dfb204aa751d44271cd1971 100755
--- a/scripts/gnt-instance
+++ b/scripts/gnt-instance
@@ -998,7 +998,11 @@ def _FormatBlockDevInfo(idx, top_level, dev, static):
       txt = "disk %d" % idx
   else:
     txt = "child %d" % idx
-  d1 = ["- %s: %s" % (txt, dev["dev_type"])]
+  if isinstance(dev["size"], int):
+    nice_size = utils.FormatUnit(dev["size"], "h")
+  else:
+    nice_size = dev["size"]
+  d1 = ["- %s: %s, size %s" % (txt, dev["dev_type"], nice_size)]
   data = []
   if top_level:
     data.append(("access mode", dev["mode"]))