OK, so far so good. aTV Flash all up and running, external USB drive now a primary drive and recognised in iTunes, syncing up nicely now there is loads of space (2 TB!).
However, the main reason for getting such a large external drive was so that I could create some room on my Mac as I am close to using up all the space. Once I have synced all Media from my Mac onto AppleTV/External Drive, is it possible to then delete it from my Mac, safe in the knowledge that it is stored elsewhere? How would I prevent it being deleted upon the next iTune sync (without turning off the relevant selections)? If I ever want to return something that I originally deleted on my Mac but is on the External Drive, back to the Mac through syncing. SImilar to using an iPod as an external backup…
Help will be much appreciated before I go ahead and delete files only to find them trapped on an external drive.