I’ve said it before, storage is not simple. There are numerous things you have to take into account when designing and managing a storage network. The collaboration between applications, IO stacks and storage networks have to be very stable in order to get something useful out of it both in stability as well as performance. If something goes wrong its not just annoying but it might be disastrous for companies and people.
Now I’ve been involved in numerous positions in the storage business from storage administrator to SAN architect and from pre-sales to customer support and I know what administrators/users need to know in order to get things working and keep it this way. The complexity that comes to the administrators is increasing every year as does the workload. A decade ago I use to manage just a little over a terrabyte of data and that was pretty impressive in those days. Today some admins have to manage a petabyte of data (yes, a 1000 fold more). Now going from a 32GB diskdrive to a 1TB diskdrive might look like their life just simplified but nothing is further from the truth. The impact it has when something goes wrong is immense. Complexity of applications, host/storage based virtualisation etc etc have all added to an increase of skills required to operate these environments.
So what does this have to with FCoE. Think of it as this: you have two very complex environments (TCPIP/networking and FibreChannel Storage) who by definition have no clue what the other is about. Now try to merge these two together to be able to transport packets through the same cable. How we do that? We rip away the lower level of the ISO and FC layers, replace that with a new 10GbE CEE interface, create a new wrapper with new frameheaders, addressing and protocol definitions on those layers and away we go.
Now this might look very simple but believe me, this was the same with fibre channel 10 years ago. Look how the protocol evolved. Not only in speeds and feeds but also tremendously in functionality. Examples are VSAN’s, Virtual Fabrics, FibreChannel Routing to name a few. Next to that the density of the FC fabrics has increased as does the functionality on storage arrays. I already wrote in a previous article that networking people in general are not interested in application behaviour. They don’t care about IO profiles, responsetimes and some packet loss since TCPIP will solve that anyway. They just transport packets through a pipe and if the pipe isn’t big enough they replace it with a bigger pipe or re-route some of the flow to another pipe. That is what they have done for years and they are extremely good at it. Storage people on the other hand need to know exactly what it hitting their arrays and disks. They have a much more vertical approach because each application has a different behaviour on storage. If you mix a large sequential load with a very random one hitting the same arrayports and spindles you know you are in a bad position.
So here is were politics will collide. Who will manage the FCoE network. Will it be the networking people? (Hey, it’s Ethernet right? So it belongs to us!). Normally I have no problem with that but they have to prove that they know how FibreChannel behaves, what a Ficon SBC codes set looks like as well as an FCP SCSI CDB. (I see some question marks coming already)
Now FCoE doesn’t work on your day-to-day ethernet or fibrechannel switch. You have to have specialized equipment like CEE and FCF switches to get things going. Most of them are not backwards compatible so they act more as a bridging device between an CEE and FC network. This in turn add significantly to the cost you were trying to save by knocking off a couple of HBA’s and network cards.
FCoE looks great but the added complexity in addition to an entire mindshift of networking and storage management plus the need for extremely well trained personnel will make this technology sit in a closet for at least 5 years. There it will mature over time so true storage and networking convergence might me possible as a real business value add. At the time of this writing the standard is just a year old and will need some fixing up.
Businesses are looking of ways to save cost, reduce risk and simplify environments. FCoE currently gives neither of these.