Add DISK to array.

clientside/lib/libtb/tbdefs.c

 /*
  * EMULAB-COPYRIGHT
- * Copyright (c) 2000-2006 University of Utah and the Flux Group.
+ * Copyright (c) 2000-2006, 2012 University of Utah and the Flux Group.
  * All rights reserved.
  */
 
@@ -32,6 +32,7 @@ char *tbdb_objecttypes[] = {
         TBDB_OBJECTTYPE_LINKTRACE,
         TBDB_OBJECTTYPE_EVPROXY,
         TBDB_OBJECTTYPE_BGMON,
+        TBDB_OBJECTTYPE_DISK,
 	/*
 	 * NOTE: Add the object type and any events that send back COMPLETEs to
 	 * the objtype2complete array in event-sched.c:sends_complete().