Please follow this link
https://kb.netapp.com/support/index?page=content&id=1010151
Hope it helps.
A LUN clone is a space-efficient copy of another LUN. Initially, the LUN clone and its parent share the same storage space. More storage space is consumed only when one LUN or the other changes.
In releases prior to Data ONTAP 7.3, SnapVault considers each LUN clone as a new LUN. Therefore, during the initial transfer of the LUN clone, all data from the clone and the backing LUN is transferred to the secondary system.
Note:LUNs in this context refer to the LUNs that Data ONTAP serves to clients, not to the array LUNs used for storage on a storage array.
