I have a file server with MANY harddrives dedicated to various types of data. I recently purchased a 3TB drive i want to keep things that will never be deleted/altered etc. So basically, once that drive is full, its "archived" essentially & will not delete or add anything more to that drive. Since this is how the drive is intended to be used, how full can i make my 3TB drive? i know 15% for performance but that is typically of a fragmented drive (again no changes on mine) or the drive with your operating system (i have a 250GB drive dedicated as an operating system drive & it does nothing else). Thanks!