ok i'll ask this another way, with leopard on an imac can you have a single external hard drive with time machine directed to a sub folder within that hard drive. so if your using a drobo you could have a storage folder too?
remember that the drobo make all the drives virtualized as 1 volume. thus one one virtual drive. this allows the redundancy programming to work without user setup or intervention. you can create a folder and it takes care of the rest
