I am in need to migrate a Virtual machine ( running in an old OpenStack environment with only one controller).  This VM has its own disk file +  a logical volume attached to it with application data on it.   Only Cinder backend( No rbd/ceph backend configured ) for this environment.

Now I am migrating this Virtual machine to another OpenStack(ussuri  with three controllers, three compute nodes and three storage nodes) environment with ceph/rbd backend.

I am able to  export the VM with its disk file and  import it to the other openstack environment and able to boot the machine.

But  How to export the attached logical volume from the  old VM and attach to the  VM  in the other environment ? 

what is the  methodology to follow to  export this logical volume in the old openstack VM   and import to the new VM running in the other openstack environment ?

kindly share  your suggestions/expertise to perform this

Thanks in advance for your valuable guidance.

Krish