Fibre Channel Decisions Loom


If you are a storage area network (SAN) manager, it's almost decision time.

The coming year should see the general rollout of Fibre Channel over Ethernet (FCoE) technology that will allow you to lay your storage networking on top of your Ethernet, cutting out a fair bit of infrastructure in the process. So the question that presents itself, then, is: Should you? And if so, how?

FCoE has been a long time coming, so most of you should be pretty well-versed in the pros and cons. On the one hand, a single network is easier to manage and costs less to operate than separate ones. On the other, that one network will likely have to be bumped up to 10 GbE to handle all that traffic, with a healthy dose of Converged Network Adapters (CNAs) to ensure all those protocols get along.

Fortunately, there is enough FCoE equipment already in the field that we can start to see some real-world results. The County of Los Angeles, for example, is expecting to cut its power consumption in half by consolidating eight Cisco Catalyst switches to a pair of Nexus units. And coupling those with a series of CNAs will replace a fair number of network interface cards (NICs) and Fibre Channel HBAs and produce a substantial reduction in related server hardware and cabling. On the downside, there will have to be some pretty close coordination between the FC and Ethernet sides of the house-two groups that tend not to communicate too well.

The other major question is: Why bother sticking with Fibre Channel at all, considering iSCSI is Ethernet-based, and cheaper? That's truly a judgment call. Many organizations get along with iSCSI just fine. But it is important to realize that iSCSI uses TCP/IP, which is a lossy protocol. That may be fine for e-mail and data transfers in the data center, but it could be a killer for storage, particularly for critical data.

And while FCoE helps you cut down on the amount of cabling you'll need, it might make sense to invest in a higher quality. If you are mixing FCoE with 10 GbE, virtualization, blade servers and a host of other consolidation measures, perhaps some OM3 cable might be in order. Not only does it provide a high-density, modular infrastructure, it offers the ability to smoothly migrate from today's 1 G or less Ethernet all the way through 100 G. It also accommodates InfiniBand.

Sure, there's a lot to think about when it comes to FCoE. But a streamlined network infrastructure will be a crucial component for the consolidated, cloudy data center of the future. It's not like a decision has to be made tomorrow, but it is something to think about as the coming year's capital improvement plans start to take shape.