--- /usr/lib/pymodules/python2.7/nova/virt/disk.py.orig2011-07-06 20:42:05.091681276 +0200
+++ /usr/lib/pymodules/python2.7/nova/virt/disk.py2011-07-06 21:26:20.111680607 +0200
@@ -142,13 +142,14 @@
     """
     try:
         container_dir = '%s/rootfs' % target
-        utils.execute('sudo', 'umount', container_dir)
-
+
     finally:
-        out, err = utils.execute('sudo', 'losetup', '-a')
+        out, err = utils.execute('sudo', 'mount')
+
         for loop in out.splitlines():
             if instance['name'] in loop:
-                device = loop.split(loop, ':')
+                device = loop.split(' ')[0]
+utils.execute('sudo', 'umount', container_dir)
                 _unlink_device(device, nbd)