Clustered Data ONTAP 8.3

I have heard that the new feature LUN copy preserves storage efficiency and only writes out unique blocks during the transfer. Since you can copy a LUN to a different volume or fron a volume in one SVM to a volume in another SVM in the cluster, and since deduplicarion/compression are based on volumes, what happens if you move a LUN to a volume that is not configured for storage efficiency?