--- disk.py.orig	2011-08-27 17:47:38.532557753 +0200
+++ disk.py	2011-08-27 17:48:58.112557747 +0200
@@ -150,12 +150,13 @@
     """
     try:
         container_dir = '%s/rootfs' % target
-        utils.execute('umount', container_dir, run_as_root=True)
+	if os.path.ismount( container_dir ):
+        	utils.execute('umount', container_dir, run_as_root=True)
     finally:
         out, err = utils.execute('losetup', '-a', run_as_root=True)
         for loop in out.splitlines():
             if instance['name'] in loop:
-                device = loop.split(loop, ':')
+		device = loop.split(':', 1)[0]
                 _unlink_device(device, nbd)