cinder-volume service fails to start

Cinder-volume fails to start
package version - 2012.2-0ubuntu2~cloud0
OS - Ubuntu 12.04 - 3.2.0-35-generic #55-Ubuntu SMP Wed Dec 5 17:42:16 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

problem statement -
Unable to start Cinder-volume service, it fails on startup when configured to use ceph RBD backend.
The Cinder-api and Cinder scheduler service start Ok 100% of the time

Symptoms - unable to start cinder-volume with the following error appearing in cinder-volume.log:

2013-01-14 14:00:04 9327 AUDIT cinder.service [-] Starting cinder-volume node (version 2012.2-LOCALBRANCH:LOCALREVISION)
2013-01-14 14:00:04 DEBUG cinder.utils [req-2c7afcd5-12ac-414a-b175-0b449a211a4b None None] Running cmd (subprocess): rados lspools execute /usr/lib/python2.7/dist-packages/cinder/utils.py:156
2013-01-14 14:00:04 DEBUG cinder.utils [req-2c7afcd5-12ac-414a-b175-0b449a211a4b None None] Result was 254 execute /usr/lib/python2.7/dist-packages/cinder/utils.py:172
2013-01-14 14:00:04 9327 CRITICAL cinder [-] Unexpected error while running command.
Command: rados lspools
Exit code: 254
Stdout: ''
Stderr: "2013-01-14 14:00:04.291794 7fc8bffee780 -1 asok(0x14d9a70) AdminSocketConfigObs::init: failed: AdminSocket::bind_and_listen: failed to bind the UNIX domain socket to '/var/run/ceph/client.admin.so
ck': (13) Permission denied\n2013-01-14 14:00:04.292146 7fc8bffee780 -1 monclient(hunting): ERROR: missing keyring, cannot use cephx for authentication\n2013-01-14 14:00:04.292152 7fc8bffee780 0 librados:
 client.admin initialization error (2) No such file or directory\ncouldn't connect to cluster! error -2\n"

if you start the service manually as per this , it does start and run:

exec /bin/sh -c "exec cinder-volume --config-file=/etc/cinder/cinder.conf --log-file=/var/log/cinder/cinder-volume.log" cinder

the service stays up and connects to RBD volumes successfully

I suspect i need to do something to Cinders rootwrap configuration, but cant find a lot of guidance as to how to get this setup

Any suggestions or guidance would be really appreciated

My Cinder.conf is as follows:

[DEFAULT]
debug=true
sql_connection = mysql://cinder:(pw>@<cloud controller IP>:3306/cinder
rabbit_password = <rabbitpw>
rootwrap_config = /etc/cinder/rootwrap.conf
api_paste_confg = /etc/cinder/api-paste.ini
volume_driver = cinder.volume.driver.RBDDriver
rbd_pool=nova
rbd_user=admin
rbd_secret_uuid=<secretUIUIDHere)
volume_tmp_dir=/var/lib/nova/voltemp
#### (StrOpt) where to store temporary image files if the volume driver
#### does not write them directly to the volume
# iscsi_helper = tgtadm
volume_name_template = volume-%s
volume_group = volumes
# verbose = True
auth_strategy = keystone
state_path = /var/lib/cinder
# volumes_dir = /var/lib/cinder/volumes

Also, if there is a detailed installation guide showing all configuration steps needed to integrate Cinder into Openstack and Ceph, I'd appreciate a link to any documentation available