I want to migrate CIFS shares as well as exchange LUN from old NetApp FAS270 to the new FAS2240 , DOT on FAS270 is 7.3.3 and DOT on FAS2240 is 8.1.1 hence the aggregate on FAS270 is 32-bit and the one in FAS2240 is 64-bit.
The question is that possible to use snapmirror to migrate data from the old NetApp to the new one while they are having different DOT and different aggregate type? if not then I have to create new 32-bit aggregate on the new NetApp and i know with DOT 8.1.1 there is an option to convert the 32-bit aggregate to 64-bit without need to rebuild it , am i right?
what is your suggestion for the best practice regarding this scenario? do i need to configure CIFS setup on the new NetApp and then begin the snapmirror or I have to mirror the data and then configuring the CIFS on New NetApp ? how can i replace it with the old one withour affecting the users ? (i know i need downtime for it) and the same question for LUN.
As of DOT 8.1 you can perform VSM from a 32 bit aggregate to a destination volume on 64 bit aggregate. Check out the 7-Mode Data Protection Guide (page 90) to see the matrix. And you are correct in that you can do an in place conversion from 32->64 bit.
As for a best practice, it's really going to depend on your environment/situation and can be accomplished numerous ways. Knowing how your end users access the data (ie, are shares auto-mounted? after the upgrade, are they expecting the same names? etc) and what their expectations are will drive your course of action in the end. For the LUN, unless you're using SME, you're going to need to shut down Exchange entirely before you can start the snapmirror if you want everything to be consistent. If you dont, the data on the LUN should be considered crash consistent and the data's usability questioned (Exchange guys chime in here if I'm mistaken).