NFS
one unique(?) advantage Simplivity has over some of their competition at least is they have the ability to expose their storage externally via NFS. So if for some reason your not comfortable using the compute platform or their sizes don't meet your needs or something you have the option of using something external, which is neat.
The whole grid storage/computing concept sounds really cool, I do worry about the complexities involved especially on the storage side, it's not a simple problem to solve.