http://rwmj.wordpress.com/2013/03/12/accessing-ceph-rbd-sheepdog-etc-using-libguestfs/#comment-8806
I came across this link and  and i was able to retrieve the rbd image.

$ guestfish
><fs> set-attach-method appliance
><fs> add-drive /dev/null
><fs> config -set drive.hd0.file=rbd:pool/volume
><fs> run
 I was able to retrieve file from rbd image using the above method.

Would you please let know how to do this in a single command line. I am getting the following error

guestfish add /dev/null : config -set drive.hd0.file=rbd:ssd-clonetest-rule5/fullclone.img : run : list-partitions
guestfish: invalid option — ‘s’
Try `guestfish –help’ for more information.

anything I m doing wrong here.

I am using CentOS 6.4 2.6.32-358.6.2.el6.x86_64
qemu:

qemu-kvm-0.12.1.2-2.415.el6.3ceph.x86_64
qemu-kvm-tools-0.12.1.2-2.415.el6.3ceph.x86_64

guestfs:

libguestfs-tools-c-1.20.11-2.el6.x86_64
libguestfs-tools-1.20.11-2.el6.x86_64
libguestfs-1.20.11-2.el6.x86_64
libguestfs-winsupport-1.0-7.el6.x86_64