Facing network performance problems in its virtualized VMware environment, a San Mateo, Calif., software provider evaluated converged networking options from Cisco and Xsigo. The company found that Xsigo Systems Inc.'s offering cost about half as much as Cisco Systems Inc.'s while also providing cabling and availability benefits compared with maintaining separate Ethernet and Fibre Channel networks.
Shashi Dookhee, the director of IT at application security software provider Fortify Software Inc., said the cost of a Cisco Nexus 5000 switch deployment came from expensive converged network adapters (CNAs), which are some $1,200 each.
"With 20 hosts, each with two cards for redundancy, it starts to get pretty pricey," Dookhee said. In contrast, the InfiniBand host card adapter (HCA) cards Xsigo requires cost about $400.Xsigo: More pluses than just price
Dookhee also complained about the seeming immaturity of Fibre Channel over Ethernet (FCoE), the nascent networking protocol used by Cisco that allows Fibre Channel storage traffic to travel over 10 Gigabit Ethernet links.
"It seemed like [the Nexus switch] was based on standards that hadn't been ratified yet," Dookhee said. "It seemed like it would be difficult to add new protocols [to the Nexus switch] and that their long-term strategy hadn't been set yet."
Dookhee also wondered about the outcome when all ports on a Nexus 5000 switch are used up.
Greg Schulz, the founder and senior analyst at StorageIO, said that today, the Nexus 5000 line is indeed limited in size; shops can achieve scalability by using ports as inter-switch links between multiple Nexus switches or by using a pricier core switch.
"It's like the core/edge game on early Fibre Channel switches," Schulz said.
Dookhee thinks that Xsigo I/O Director promised better scalability. "Using relatively cheap InfiniBand switches, we can daisy-chain that as far as you want to go," Dookhee said. "That allowed us to push [the technology] further as we grew."
Schulz said Xsigo has a window of opportunity right now, as FcoE vendors such as Cisco and, eventually, Brocade Communications Systems Inc. scramble to make their "converged networking" products more mature.
Xsigo targets IT shops that want the availability and bandwidth of converged networking but don't want to go with Cisco -- either because they believe Fibre Chanel over Ethernet is too immature and expensive or because they worry about becoming too beholden to Cisco as it evolves from being a straight networking vendor, to a server vendor with its new Unified Computing System (UCS), Schulz said.A plethora of Ethernet ports
Others said that VMware shops should look long and hard at converged networking before jumping in.
Joe Skorupa, Gartner Inc.'s research vice president for networking and communications, said that VMware shops are eager to explore converged networking options to address the problem of Ethernet port proliferation in their environments.
"If you look at the typical VMware server, you have two ports for storage I/O, and two ports for server I/O. Then you have one GigE port for VMotion, one for management, and often one or two ports for backup," Skorupa said. Pretty soon you're looking at a server with six to eight Ethernet ports," he said.
But if the problem is an excess of Ethernet network interfaces, Skorupa said converged networking is not the only way to solve it.
For instance, performing incremental upgrades from Gigabit Ethernet and 4 Gb Fibre Channel to 10 GbE and 8 Gb Fibre Channel can increase bandwidth and preempt the internal politics between network and storage teams.
"Storage and network guys report up through different management teams, and openly loathe one another," Skorupa said. "The storage guys view the network guys as cowboys that don't know how to run a production network, and the network guys think of the storage guys as Luddites living in the 1800s." By sticking with separate Ethernet and storage networks, that turf battle can be sidestepped, he said.
Fortify's Dookhee explored that route, but in addition to wanting more bandwidth, the firm also wanted the better availability that comes with redundant HCAs. The firm's 1U servers have room for only two slots, which would have eliminated the possibility for redundancy if they'd chosen to go with separate Fibre Channel and 10 GbE cards.
Gartner's Skorupa conceded that some folks aren't comfortable with a single physical adapter but that, for most shops, going with redundant ports is sufficient.
"People have been doing dual-port adapters for years," he said. "You don't need to have a belt and suspenders; it's more than good enough."
IT managers can also consider running FcoE on generic network interface cards or PCI Express-based approaches from companies such as NextIO Inc. and Virtensys. Or they can go with tried-and-true approach of iSCSI storage over Ethernet.
"People don't appreciate that there are a lot of viable ways to do converged networking. It's not all about FcoE. A lot of the time, we forget about the stuff that's already there and working."
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