OK, I’ll admit that sometimes I am a bit cynical. And skeptical too; teenagers will do that to a guy.

So I am squinting down on this whole FCoE thing, wondering what Promised Land it will lead to… and what the cost will be. Do I have to throw out all my gear and get new stuff?  Is it good for this, but not for that? If we build systems around it are we going to be sued for patent infringement by people who standardized it? Can we have a bailout?

OK, the last question is a cheap shot against, well, everyone who wants a bailout which these days seems like just about well, everyone. My Uncle Al wants a bailout because he forgot to drain the water from his sprinkler system before it froze. Al figures Uncle Sam is good for 3,000 rescue bucks. After all, if AIG is worth $50 billion, Al is worth at least three grand.

Before addressing the other questions, I figured I better review what FCoE is first. Al knows damn near everything, but he wasn’t any help on this one. And if you read this Blog, you know that my mother-in-law isn’t talking to me because of my little joke about her Gmail going down for a year. Needless to say, that source of knowledge dried up like Uncle Al’s front lawn.

Are you ready?  FCoE stands for Fibre Channel over Ethernet. Well, that was easy. Great idea huh? Seems like Al should’ve known this one. Ya gotta love Wikipedia.

Appendix (i.e. content)

If you have a clean sheet of paper, do you design two or three different networks to connect your gear or do you just change the protocols and layers on a single network as the applications demand? Of course you design one physical network and layer the protocols to accomplish the networking task at hand. The bad news: it wasn’t done that way. (The parallels between standard storage products and Pillar Axiom are almost too strong to ignore, but in the interest of leaving the Axiom plug out of this, I will stick to networking. You can thank me later.)

Instead of one, we have multiple networks. We have the two “biggies” namely Ethernet and Fibre Channel.  They are physically different, and operate at slightly different speeds. Ethernet, the more popular of the two, has probably over a half billion port install base. To say this garners the power of volume is an understatement. Because of the layering of functionality, Ethernet equipment ranges from $39 hubs to $539,000 big-iron switches. Nice. Everyone loves it because you plug stuff into Ethernet and it just works.

Then there’s Fibre channel. Fibre channel has been the purview of the Enterprise storage gang.  It is expensive, requires very costly HBA’s, and is far from ubiquitous.  It has a deserved reputation for being finicky and easy to foul up without even trying.  On the plus side, it has the key properties of high performance and ensured delivery that are very desirable for connecting Servers to storage.

FCoE attempts to address fibre channel’s strengths while maintaining all the advantages of Ethernet.

We already agreed that if you could deploy one set of technologies to solve networking requirements you would. But originally, you couldn’t. Therefore, there are two incompatible networks out there, and we should look at what that means. Figure 1A shows our current world, while Figure 1B shows what the world might look like if we simplified and integrated FCoE into our current datacenter .In Figure 1A, you have two sets of switches, thus double the management and configuration. In Figure 1B, you only have one set of switches.

Today, different people with different skills usually manage your Ethernet and fibre channel networks and therein lies some of the problem: turf battles.

The first thing people say when you propose combining storage and TCP/IP traffic is that you don’t want to share network resources between some dude surfing the net and a server doing serious application work on a Storage Array.  Well, chillax… because besides QoS parameters (like Axiom has – sorry couldn’t resist) that prioritize correctly, high end Ethernet switches allow you to isolate the storage traffic from TCP/IP using VLAN’s.  But people still worry, “If the switch is still shared, how can you do that?”  The answer is that if you have a big enough switch, and the network connections are sized properly (let’s say 1Gbit to clients via distribution switches, 10Gbits to Axioms and servers for example), the switch resources will handle both kinds of traffic just fine.  These big switches are often underutilized anyway, so combining them reduces waste.

Wait a Minute…

What about iSCSI? – isn’t this what iSCSI was supposed to accomplish: storage connected through the Ethernet using TCP/IP? Well, yes it is, but it missed the mark for the Enterprise. And Dell paid $1.4B for Equalogic, an iSCSI storage company.  While some people interpreted Dell’s purchase as iSCSI taking over the planet, most people decided that iSCSI was locked into the SMB (Small –Medium Business) market, and the data center still needed a better solution. The problem is that TCP/IP is a “lossy” protocol; it’s OK to drop packets and resend them later. TCP/IP also has unpredictable latency; while  adequate for client-server communication, it is not the tight coupling that high performance applications on servers need for their storage attachments in the data center.

So let’s do a comparison between Fibre Channel, iSCSI and FCoE

Packet descriptions of Ethernet used for three purposes: 1) Client communication, 2) Proposed Storage connection with predictable latency and lossless properties, 3) Routable lossy iSCSI connection to less demanding storage applications.

So what does the advent of FCoE mean to the storage industry? As you can see, it’s all about consolidation. Server Virtualization enables you to use more server resource, Application-Aware storage means that you can use 80% of your storage resource, and FCoE means that you can use more of your Ethernet infrastructure resource and eliminates your fibre channel infrastructure. Consolidation eliminates the costs of a second infrastructure, such as power and cooling, management costs, maintenance, training, spares, etc. Like all new technologies, it should make our lives a little simpler.

Timing… let’s acknowledge that these things always take longer than the proponents claim they will. While the world will not be FCoE by end of 2009 or 2010 for that matter. You will begin to see people buying FCoE-ready equipment rather than FCoE-incompatible gear. Count on Pillar to accept and support FCoE in your infrastructure. Truth is, we don’t care either way; we make what Customers want to buy. On the other hand, we do have opinions, and our opinion is that FCoE should be a good thing. In an upcoming post I will put forward a simple economic analysis of FCoE versus currently available alternatives. After all, until the economics of FCoE are a clear incentive, it will be a false promise.

Related Links:

In my opinion one of the best overview/comparison articles out there was written by Chris Mellor.