When I try to enter my rMBP into sleep mode while downloading file via iTunes U, the downloaded file is aborted. Is it possible to enter sleep mode while keep downloading the file?
EDIT: Until I find better option I put my display to sleep and not the computer. Check this to see how quickly enter this mode: What Is the Keyboard Shortcut for Sleep Display Without Eject Key?
Best Answer
Have a Mac in sleep mode while also downloading a file with iTunes, is currently not possible.
However the idea is not out the question, doing things while in sleep is possible on certain new Mac hardware running OS X 10.8, via the new Power Nap feature.
What you asking to do is currently not a feature of Power Nap, however it is something that might be possible with a hack or a future version of Power Nap.
Therefore Power Nap can only do the following: