Please note, once migrated to 6.0, you can't go back to 5.3.X, without zeroeing the disks.
This is in direct conflict from what an engineer at NetApp Munich Germany said. He said that 5.X would realize the filesystem has changed and revert it back. We were very doubtful of this and would have wanted triple confirmation from them.
Tuc/TTSG Internet Services, Inc.