Fibre Channel: Generations
April 18, 2013 3 Comments
In case you haven’t heard, Brocade is rebranding their 16 Gbit Fibre Channel offerings as Generation 5 Fibre Channel. Upcoming 32 Gbit Fibre Channel will also be called “Gen 6 Fibre Channel”. Seriously.
Brocade is trying to de-emphasize speed as the primary differentiator to a specific Fibre Channel technology, which is weird, since that’s by far the primary differentiator between the generations. This strategy has two major flaws as I see it:
Flaw #1: They’re trying to make it look like you can solve a problem that you really can’t with 16 Gbit FC. Whether you emphasize speed or other technological aspects of 16 Gbit Fibre Channel, 16 Gbit/Gen 5 isn’t going to solve any of the major problems that currently exists in the data center or storage for that matter, at least for the vast majority of Fibre Channel installations. Virtualization workloads, databases, and especially VDI are thrashing our storage systems. However, generally speaking (always exceptions) we’re not saturating the physical links. Not on the storage array links, not on the ISLs, and definitely not on the server FC links. Primarily the issue we face in the data center are limitations are IOPS.
The latency differences between Fibre Channel speeds is insignificant compared to the latencies introduced by overwhelmed storage arrays
Or, no wait, guys. Guys. Guys. Check out the… choke point.
16 Gbit can give us more throughput, but so can aggregating more 8 Gbit links, especially since single flows/transactions/file operations aren’t likely to eat up more than 8 Gbit (or even a fraction of that). There’s a lower serialization delay and lower latency associated with 16 Gbit, but that’s minuscule compared to the latencies introduced by storage systems. The vast majority of workloads aren’t likely to see significant benefit moving to 16 Gbit. So for right now, those in the storage world are concentrating on the arrays, and not the fabric. And that’s where they should be concentrating.
From one of Brocade’s posts, they mention this of Gen5 Fibre Channel:
”It’s about the innovative technology and unique capabilities that solve customer challenges.”
Fibre Channel is great. And Brocade has a great Fibre Channel offering. For the most part, better than Cisco. But there isn’t any innovation in this generation of Fibre Channel other than the speed increase. I’m kind of surprised Brocade didn’t call it something like “CloudFC”. This reeks of cloud washing, without the use of the word cloud. I mean, it’s Fibre Channel. It’s reliable, it’s simple to implement, best practices are easily understood, and it’s not terribly sexy, and calling it Gen5 isn’t going to change any of that.
Flaw #2: It creates market confusion.
Cisco doesn’t have any 16 Gbit Fibre Channel offerings (they’re pushing for FCoE, which is another issue). And when they do get 16 Gbit, they’re probably not going to call it Gen 5. Nor is most of the other Fibre Channel vendors, such as Emulex, Qlogic, NetApp, EMC, etc. HP and Dell have somewhat gone with it, but they kind of have to since they sell re-branded Brocade kit (it’s worth noting that even HP’s material is peppered with the words “16 Gbit”). So having another term is going to cause a lot of unnecessary conversations.
Here’s how I suspect a lot of Brocade conversations with new and existing customers will go:
“We recommend our Gen 5 products”
“What’s Gen 5?”
“It’s 16 Gbit Fibre Channel”
“OK, why didn’t you just say that?”
This is what’s happened in the load balancing world. A little over six years ago, Gartner and marketing departments tried to rename load balancers to “Application Delivery Controllers”, or ADCs for short. No one outside of marketing knows that the hell an ADC is. But anyone who’s worked in a data center knows what a load balancer is. They’re the same thing, and I’ve had to have a lot of unnecessary conversations since. Because of this, I’m particularly sensitive to changing the name of something that everyone already knows of for no good frickin’ reason.
Where does that leave Fibre Channel? For the challenges that most organizations are facing in the data center, an upgrade to 16 Gbit FC would be a waste of money. Sure, if given the choice between 8 and 16 Gbit FC, I’d pick 16. But there’s no compelling reason for the vast majority of existing workloads to convert to 16 Gbit FC. It just doesn’t solve any of the problems that we’re having. If you’re building a new fabric, then yes, absolutely look at 16 Gbit. It’s better to have more than to have less of course, but the benefits of 16 Gbit probably won’t be felt for a few years in terms of throughput. It’s just not a pain point right now, but it will be in the future.
In fact, looking at most of the offerings from the various storage vendors (EMC, NetApp, etc.), they’re mostly content to continue to offer 8 Gbit as their maximum speed. The same goes for server vendors (though there are 16 Gbit HBAs now available). I teach Cisco UCS, and most Cisco UCS installations plug into Brocade fabrics. Cisco UCS Fibre Channel ports only operates at a maximum of 8 Gbit, and I’ve never heard a complaint regarding the lack of 16 Gbit. Especially since you can use multiple 8 Gbit uplinks to scale connectivity.