Acoording to you, which is best method for migrating the data from 32 bit to 64 bit aggregates..
3) qtree Snapmirror
Typical qsm number 3. For incremental updates as long as needed. Or if you can wait to upgrade to 8.1 then you can mirror 32 to 64 with vsm.
There was a fairly tedious procedure described somewhere on communities telling how to also migrate snapshots with qsm.
A kb a while ago too. Really crazy procedure with a lot of replications for each snap
Sent from my iPhone 4S
Of course, 8.1 adds fourth possibility - convert 32 to 64 in place