I wound up finding GlusterFS that suited my needs. It allows you to span hard drives across multiple networked systems and mount all machines as 1 drive. Now I’m suddenly finding a possible use for all of those old systems around the house.

The only limit to how big you go is how many machines you have linked together and how fast your network is. You’ll need a fast backbone to pull GB/sec but I have seen places on their site make reference to some really impressive numbers.

I’m at the researching stage at this point and garhering materials, so as soon as I have a working model I will post a howto on my setup and any issues I run into.