Merge "Improve error message on volume tests failure"
diff --git a/tempest/api/volume/v2/test_volumes_list.py b/tempest/api/volume/v2/test_volumes_list.py
index 7717027..03996af 100644
--- a/tempest/api/volume/v2/test_volumes_list.py
+++ b/tempest/api/volume/v2/test_volumes_list.py
@@ -73,9 +73,13 @@
             val0 = fetched_volume[0][sort_key]
             val1 = fetched_volume[1][sort_key]
             if sort_dir == 'asc':
-                self.assertLess(val0, val1, "%s < %s" % (val0, val1))
+                self.assertLess(val0, val1,
+                                "list is not in asc order with sort_key: %s."
+                                " %s" % (sort_key, fetched_volume))
             elif sort_dir == 'desc':
-                self.assertGreater(val0, val1, "%s > %s" % (val0, val1))
+                self.assertGreater(val0, val1,
+                                   "list is not in desc order with sort_key: "
+                                   "%s. %s" % (sort_key, fetched_volume))
 
         _list_details_with_multiple_params()
         _list_details_with_multiple_params(sort_dir='desc')