the old filer is cluster mode , 8.3 ontap version , it is v32340 which is a very old system
the new filer is Fas2720 , probably will be received with ontap 9.8 version ,
the disk assignment is ok, but i am not really sure about the snapshots of the snapvault destination volumes
we mustnot loose them , because they are the customers long time archival backup data.
anyway thanks a lot for your answers