Earlier, we described a LUN. In Xsan you can take multiple LUNs and stream data to them in a round-robin fashion. When doing so you will group them together in what Xsan calls Storage Pools. Each Storage Pool has a maximum throughput of about 4 LUNs worth of storage. Each of the LUNs (in Xsan 1.0) has a maximum of about 2TB in capacity. Therefore each Storage Pool can typically net you around 4gbps of speed and about 8TB in capacity. You can then lump multiple Storage Pools into a given Volume to obtain volume sizes of 32, 40, 48, etc. TB. However, when you do so you will not attain more than 4gbps of concurrent streams from one host to the storage. But instead, you are increasing your aggregate bandwidth between hosts.