Are there any alternatives for time machine? I want something (at least 4 TB) that can be partitioned into half for time machine, and the other for external storage. Being able to access it over the internet would be a bonus... I read somewhere that I can use the WD Live Duo (6tb) + an airport extreme, but does anyone have experience with this and partioning it for the above usage? I also read about Synology but is there a model that is affordable that can do the above?