Comment 0 for bug 1337821

I have booted an instance from a volume, successfully booted,
now another volume, i try to attach to same instance, it is failing.
see the stack trace..

2014-07-04 08:56:11.391 TRACE oslo.messaging.rpc.dispatcher raise exception.InvalidDevicePath(path=root_device_name)
2014-07-04 08:56:11.391 TRACE oslo.messaging.rpc.dispatcher InvalidDevicePath: The supplied device path (vda) is invalid.
2014-07-04 08:56:11.391 TRACE oslo.messaging.rpc.dispatcher
2014-07-04 08:56:11.396 ERROR oslo.messaging._drivers.common [req-648122d5-fd39-495b-a3a7-a96bd32091d6 admin admin] Returning exception The supplied device path (vda) is invalid. to caller
2014-07-04 08:56:11.396 ERROR oslo.messaging._drivers.common [req-648122d5-fd39-495b-a3a7-a96bd32091d6 admin admin] ['Traceback (most recent call last):\n', ' File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 134, in _dispatch_and_reply\n incoming.message))\n', ' File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 177, in _dispatch\n return self._do_dispatch(endpoint, method, ctxt, args)\n', ' File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 123, in _do_dispatch\n result = getattr(endpoint, method)(ctxt, **new_args)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 401, in decorated_function\n return function(self, context, *args, **kwargs)\n', ' File "/opt/stack/nova/nova/exception.py", line 88, in wrapped\n payload)\n', ' File "/opt/stack/nova/nova/openstack/common/excutils.py", line 82, in __exit__\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/opt/stack/nova/nova/exception.py", line 71, in wrapped\n return f(self, context, *args, **kw)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 286, in decorated_function\n pass\n', ' File "/opt/stack/nova/nova/openstack/common/excutils.py", line 82, in __exit__\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 272, in decorated_function\n return function(self, context, *args, **kwargs)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 314, in decorated_function\n kwargs[\'instance\'], e, sys.exc_info())\n', ' File "/opt/stack/nova/nova/openstack/common/excutils.py", line 82, in __exit__\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 302, in decorated_function\n return function(self, context, *args, **kwargs)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 4201, in reserve_block_device_name\n return do_reserve()\n', ' File "/opt/stack/nova/nova/openstack/common/lockutils.py", line 249, in inner\n return f(*args, **kwargs)\n', ' File "/opt/stack/nova/nova/compute/manager.py", line 4188, in do_reserve\n context, instance, bdms, device)\n', ' File "/opt/stack/nova/nova/compute/utils.py", line 106, in get_device_name_for_instance\n mappings[\'root\'], device)\n', ' File "/opt/stack/nova/nova/compute/utils.py", line 155, in get_next_device_name\n raise exception.InvalidDevicePath(path=root_device_name)\n', 'InvalidDevicePath: The supplied device path (vda) is invalid.\n']