Does Isilon distribute data across its nodes by percentage or by quantity? e.g. if you have 4 nodes with 300GB drives and 4 nodes with 600GB drives, will Isilon put twice as much data on the bigger nodes (so they're at the same usage percentage as the smaller nodes) or will it put the same amount of data (i.e. total divided by on each node? The former would make more sense to me, but I wanted to check.

Thanks!