Demartek Takes First Look at Emulex 10Gbps iSCSI UCNA

18 December 2009

Emulex sent some of its iSCSI UCNA cards to the Demartek lab in order to take a “first look” at these 10Gbps adapters with full iSCSI offload. We installed one of these cards into one of our “Nehalem” servers running Windows Server 2008 and connected it to our 10Gb Ethernet/DCB/FCoE infrastructure. This infrastructure includes a Cisco Nexus 5020 switch and a NetApp filer running iSCSI, FCoE, and other protocols.

Because the Emulex iSCSI UCNA has full iSCSI and TCP/IP offload, we expected some performance and host CPU efficiency gains when compared to other 10Gb adapters in this environment. We also expected that this adapter would be known to the host system as a storage rather than a network adapter, as has been our experience in the past with 1Gb iSCSI offload adapters. Also, because this adapter has full iSCSI hardware offload, no iSCSI software initiator is required.

The installation of the Emulex UCNA was smooth and would be very familiar to those who have installed the Emulex Fibre Channel (FC) HBAs. The Emulex management software, “OneCommand” manages the existing Emulex FC HBAs and their new UCNA cards. Using OneCommand, we were able to establish the iSCSI sessions to the iSCSI storage target. This process was intuitive and, we believe, would be very straightforward for any administrator familiar with iSCSI storage. Although we have experience with many storage systems and technologies, I might add that we completed the installation without referring to any documentation.

We ran some preliminary performance tests just to see how well this Emulex iSCSI UCNA performs and compared the results with similar tests we have performed with other 10Gb adapters in our lab. We noted that for block sizes 4K and higher, especially for read operations, the host CPU consumption was less than with other 10Gb adapters that we have tested in the Windows Server environment, while the performance was higher. We attribute these positive results to the full iSCSI and TCP/IP offload of this Emulex iSCSI UCNA.

We will conduct more extensive tests with these and other new 10Gb “unified” adapters in the future. We would expect to see even stronger benefits in large virtualized server environments, where CPU utilization rates tend to be higher and predictable performance is required.

Action item: IT managers and administrators should take a good look at the new crop of converged network adapters, especially those with offload features, as they plan additions and upgrades to their data centers. We believe that the benefits of this new crop of “converged” or “unified” adapters will be especially strong in virtualized server environments.