I am using devstack on ubuntu 12.04. When starting the rejoin-stack.sh after a reboot, the scripts hangs at the command

cd /opt/stack/cinder && /usr/local/bin/cinder-volume --config-file /etc/cinder/cinder.conf

with the message

2013-07-08 16:55:12.935 ERROR cinder.openstack.common.rpc.common   [req-94a7b477-794b-4679-864d-dd6deb7ba5e8 None None] AMQP server on localhost:5672 is  unreachable: Socket closed. Trying again in 1 seconds.
2013-07-08 16:55:13.939 INFO cinder.openstack.common.rpc.common [req-94a7b477-794b-4679-864d-dd6deb7ba5e8 None None] Reconnecting to AMQP server on localhost:5672
2013-07-08 16:55:14.006 DEBUG amqp [-] Start from server, version: 0.9, properties: {u'information': u'Licensed under the MPL.  See http://www.rabbitmq.com/', u'product': u'RabbitMQ', u'copyright': u'Copyright (C) 2007-2011 VMware, Inc.', u'capabilities': {u'exchange_exchange_bindings': True, u'consumer_cancel_notify': True, u'publisher_confirms': True, u'basic.nack': True}, u'platform': u'Erlang/OTP', u'version': u'2.7.1'}, mechanisms: [u'PLAIN', u'AMQPLAIN'], locales: [u'en_US'] from (pid=4554) _start /usr/local/lib/python2.7/dist-packages/amqp/connection.py:706

It is true that there is no one listening (at least on ipv4):

root@devstack:~# netstat -tulpen |grep 5672
tcp6       0      0 :::5672                 :::*                    LISTEN      104        9733        1285/beam.smp

What am I missing? What could I do to further debug this?