OpenNebula

I have installed opennebula within sunstone and rbd (ceph)
I have one problem

I create an image in rbd datastore (through sunstone or command line, no difference)

- Case 1 command line
I create a VM from command line
onevm create --name vm1 --cpu 1 --mem 1024 --disk image1 --vnc --nic 1
the VM uses the image (image1) for disk which is in rbd
Live migrate works perfect
Failover works perfect

the command line for this vm is
/usr/bin/kvm -name one-36 [blah...blah] -drive file=rbd:one/one-9:auth_supported=none,if=none,id=drive-ide0-0-0,format=raw,cache=none [blah...blah]

So the disk is the rbd block device and only that, which is distributed to all physical hosts through ceph

- Case 2 though sunstone
I create a VM template using the same image (image1) (persistent or not)
I create a VM with that template
and the command line is
/usr/bin/kvm -name one-35 [blah...blah] -drive file=/var/lib/one//datastores/0/35/disk.1,if=none,media=cdrom,id=drive-ide0-0-0,readonly=on,format=raw [blah...blah] -drive file=rbd:one/one-8:auth_supported=none,if=none,id=drive-ide0-0-1,format=raw,cache=none [blah...blah]

As you see in the second case there is a file as drive, so when i try to migrate or to failover by crashing the server, the VM does not migrate/failover because is missing the file
If i do a shared storage, it migrates the VM but it does not failover because it tryies to copy the file from the crashed server(?) and even if it migrates it will loose all data which are in file

So is there a way to create a VM which reads and writes in the rbd directly and not on a file with sunstone?
Is it a bug or lack of feature?