diff -r c6f637694b85 tools/python/xen/xm/main.py
--- a/tools/python/xen/xm/main.py	Fri Dec 15 11:53:45 2006 +0000
+++ b/tools/python/xen/xm/main.py	Sat Dec 16 00:16:07 2006 -0500
@@ -1556,7 +1556,11 @@ def detach(args, command, deviceClass):
 
 
 def xm_block_detach(args):
-    detach(args, 'block-detach', 'vbd')
+    try:
+        detach(args, 'block-detach', 'vbd')
+        return
+    except:
+        pass
     detach(args, 'block-detach', 'tap')