[Users] Disk live migration ..isuue

Hi Guys anyone have any idea why after move disk from 1 storage domain to another it creates 2 disks under target domain 1- preallocated 2- thin pro Please find attached output below moved VM-2_disk1 from "VM-disk" storage domain to "Migration domain" But under *"Migration" *storage domain 2 disk & under "*virtual machine"*disk section only 1 disk ..why .. is it due to snapshot which was created while move or do we need to manually delete another disk after move. Thanks Anil D