I would appreciate advice on how to best set up my 3TB external USB Hard Drive (currently attached to my MacBook Pro) so that my MacBook Air can use it as well. My goal is to have only program/system files on the MBP 128GB SSD and MBA 64GB SSD while all downloads and media go on the 3TB HD. I would also like my iPhone and iPad to be able to access what's on the 3TB HD. I've already moved the MBP 'Home' folder to the external drive which seems to get the job done and would like to do the same for the MBA. Ideally, I would like one 'Home' folder for both but not sure that's possible. I've looked into System Preferences > File Sharing but want access restricted to only my MBA but without having to enter passwords all the time (MAC address filtering)?