I'm looking at enclosures that can hold 60 disks. So 3TB SAS disks would be 180TB. Most enclosures of that kind have dual everything. Some SAS drives even have

I'm looking at enclosures that can hold 60 disks. So 3TB SAS disks would be 180TB. Most enclosures of that kind have dual everything. Some SAS drives even have dual connections I believe (should look that up again). At some point it's really a function of the size of the drives that makes the volume large. I think 60 drives is going to pretty much be the physical limit in 4 rack units. You can buy the NL-108 from Isilon which has 108TB (36 3TB disks) if you want "enterprise." ;) Eventually they'll use 4TB drives in those.