Another update: Sun Storage 7210
The Sun Storage 7210 (an appliance based on the X4540) got an slight update as well. You can connect up to 2 additional J4500. The J4500 is a JBOD with up to 48 harddisks on 4 Rack unit. Essentially it´s a X4540 without the Opterons but with a SAS I/O module. At the end this gives you a filer with 142 TB of storage on 12 rack units. The option to connect those JBODS is available to existing customers of the 7210, too.