The USS is a minor upgrade which adds high-availability support and NFS and Lustre RDMA that can improve throughput and reduce CPU utilization. Chelsio's Unified Manager lets administrators discover and manage Chelsio iSCSI initiators, TCP Offload Engines and NICs. UM eases adapter configuration from a central point, alleviating the need to login to multiple consoles.
The USR is a 1U rack mount iSCSI to FC gateway. The USR has two blades for a high availability installation. The USR sports two 10Gb Ethernet ports, two 1Gb Ethernet ports, and two 8Gb FC ports. The USR supports iSCSI connections from common operating systems like Windows, Red Hat Enterprise Linux, SuSe Enterprise Linus, VMware, Xen and others. Representatives from Chelsio said the USR can offer "900,000 IOPs with our 10GbE hardware and iSCSI stack, and with SSD drives, we can get the maximum IOPs that the SSD drives are capable of. We have demonstrated 330,000 IOPs with four FusionIO SSD drives at Storage Network World."
Howard Marks, founder and chief scientist of deepstorage.net and a Network Computing contributor says, "This one of those product categories that won't go anywhere. There are iSCSI shops that don't want to migrate to FC because of the cost, and they don't want to learn a new protocol. There are FC shops that don't want iSCSI because they get what they need from FC. But if you want both, EMC Clarion and Symetrix storage arrays, which make up 80 percent of the market, support both iSCSI and FC simultaneously."
The USR, like the HP Network Storage Gateway OEM'd from Qlogic and Brocade's iSCSI Gateway, is a transitional appliance. The iSCSI vs FC debate is largely a religious war. With the coming proliferation of 10Gb in the data center, one of the biggest barriers to iSCSI adoption--network capacity--will disappear. This means IT shops can decide on FC, iSCSI, FCoE, or some other storage protocol based on need and product availability. The USR should help IT transition to or from iSCSI or FC.