diff --git a/lib/hypervisor/hv_xen.py b/lib/hypervisor/hv_xen.py
index 326fccd13d90e4ff71ba81be2eadb4350c01e00a..df6a2dcd9371fc78f77577fca436bb21004faaeb 100644
--- a/lib/hypervisor/hv_xen.py
+++ b/lib/hypervisor/hv_xen.py
@@ -172,10 +172,16 @@ def _GetInstanceList(fn, include_node, _timeout=5):
 #
 # An instance is running if it is in the following Xen states:
 # running, blocked, or paused.
+#
+# A state of nothing '------' means that the domain is runnable but it
+# is not currently running.  That means it is in the queue behind
+# other domains waiting to be scheduled to run.
+#   http://old-list-archives.xenproject.org/xen-users/2007-06/msg00849.html
 def _IsInstanceRunning(instance_info):
   return instance_info == "r-----" \
       or instance_info == "-b----" \
-      or instance_info == "--p---"
+      or instance_info == "--p---" \
+      or instance_info == "------"
 
 
 def _IsInstanceShutdown(instance_info):