Hey all, and phreon.
I have a 14TB nas/mini server/seedbox/downloader running and had the same problem a while back. Watched movies on my HTPC in TV room, and hdd would sleep, wake up 2 seconds later, causing a pause in the movie.
Download a program called hdd no sleep, works wonders. 1 or 2 things to change in the .ini file, but works really well.