> 2TB ?

Forgive me as this is probably a silly question and one that has been
answered many times, I have tried to search for the answers but have
ended up more confused than when I started.  So thought maybe I could
ask the community to put me out of my misery

Is there a version of MD that can create larger than 2TB raid sets?  

Obviously with 400GB drives being commonplace a typical 12 bay solution
is capable of significant capacity, but if we need to split this down
into multiple raid sets, then we start to lose.  

So, if anyone can advise me as to MD / Linux size limitations I would be
grateful :)