Because I/O virtualization and Fibre Channel over Ethernet (FCoE) technology both aim to reduce the physical infrastructure
at the server/network interconnect, users may be confused about how Cisco Systems Inc.'s Unified Computing System (UCS) and FCoE support in the company's Nexus switches play in this space. In addition, many IT organizations find the choice between the approaches taken by Xsigo Systems Inc. and PCI Express (PCIe) a difficult one. Jeff Boles, senior analyst and director, validation services at Hopkinton, Mass.-based Taneja Group, advises thinking of Cisco's approach as more of a transport technology similar to how Xsigo uses InfiniBand and the PCIe approach uses the extended PCIe bus.
Greg Schulz, founder and senior analyst at Stillwater, Minn.-based StorageIO Group, said FCoE does not compete with I/O virtualization products as much as it complements them. Schulz explained I/O virtualization as the "close-in" solution -- the connections between the servers, I/O device and core network -- and FCoE as a data center and campus-wide transport solution.
Both analysts also stress examining your environment to determine which approach best fits your needs. Boles said there are significant ease-of-use differentiators between the technologies and products. "Look at the vendors you're thinking about using and compare their ease of use for both the virtualized network fabric you are likely to implement and their overall product suite," Boles said. "We see significant differentiation showing up here, and you are likely to realize a solution that's much easier to use or nearly hands-off as far as a localized virtualized networks solution."
If you are running or planning a highly virtualized server environment, Boles said Xsigo's virtual network interface cards (NICs) and host bus adapters (HBA)s are a better fit because of their ability to follow virtual machines (VMs) across physical servers.
Schulz also pointed out the equipment difference. If you want to get rid of all your NICs and HBAs, look at the Xsigo approach. If you want to use your existing I/O cards and plan to keep buying them, consider the PCIe approach. Schulz believes that the OEMs and major server vendors will ultimately include the PCIe approach technologies in their blade and standalone servers, and that will change the market dynamics considerably.
"I see [Xsigo and PCIe technologies] existing side by side for a while because Xsigo has a good window of opportunity while people are waiting for the [converged data center to] mature," he said. According to Schulz, as the PCIe approach gains momentum and support from blade server vendors, economics of scale will start to play in the long term.
"That's when you'll start to see Single-Root IOV [SR-IOV] and Multi-Root IOV [MR-IOV] built right on to the boards, and then all of a sudden, the game changes," Schulz said. "What approach are they going to take? It's going to be one of those types of approaches like you are seeing with Aprius, VirtenSys and NextIO … Xsigo loses its advantage as an independent alternative."