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Storage Networks

Hybrid vs. Purpose-Built: FCoE, Fibre Channel, Toyota Prius, and BMW M3

by Scott Shimomura on ‎06-21-2012 04:07 PM (14,652 Views)

On my way into work the other morning, I was contemplating the role of FCoE in the data center when a Toyota Prius passed me at about 90 mph. I had to laugh at the irony of a lead foot driver in one of the most fuel-efficient vehicles on the road. It reminded me of Top Gear’s comparison of fuel economy between a Toyota Prius and a BMW M3. (at about 3:30 into the segment).

Then I started to think about relationships between FCoE, Prii (the plural of Prius, seriously?), Fibre Channel, and M3s . It dawned on me... the Prius is a hybrid car (gas/electric) and FCoE is a hybrid network (Fibre Channel and Ethernet). Both were created to drive efficiency and provide economic benefits. On the other hand the M3 is a purpose-built sports car and Fibre Channel is a purpose-built network for storage. They were created to provide the ultimate combination of performance and reliability. Hybrid and purpose-built technologies deliver unique value when used for their intended purpose.

Edited Prius picture.pngEdited M3.jpg

Just because a Prius can go 90+mph doesn’t mean it should. Taking a logical leap, I would suggest that just because FCoE supports multi-hop, right now it’s probably better suited for “edge” top-of-rack and blade deployments. Edge deployments provide cost savings and infrastructure simplification through consolidation of adapters, switches, and cables. Moving beyond edge to end-to-end, multi-hop deployments introduces the complexities of layer 8-9 and technology obstacles.  Even Ethernet experts are conflicted with the technology.

It’s taken several generations and many years for Fibre Channel to become a trusted technology in the data center. There are tested and proven architectures that are supporting mission critical applications in the vast majority of the world’s leading businesses.  Customers continue to adopt Brocade’s Fibre Channel directors, switches, and adapters in record numbers, demonstrating the strong demand for Fibre Channel solutions.

So which direction should customers go?

“It isn’t what you drive that matters, it’s how you drive it,” opined Top Gear’s Jeremy Clarkson about the Prius and the M3. The same can be said with the many discussions and flame wars on storage networks and protocols. At the end of the day there isn’t one solution to solve all networking problems. In general, the application requirements should drive the infrastructure. Fibre Channel is still the right choice for applications that require the highest levels of uptime, reliability, and performance. FCoE is a complementary technology that will continue to evolve as the technology matures. Note, I am not ruling out the general adoption of multi-hop FCoE. If you can make a race car out of a Prius…


Just for fun (meaning have a sense of humor), I put together a table to help navigate the decisions ranging from FCoE vs. Fibre Channel networks, Toyota Prius vs. BMW M3:


Fibre Channel

Toyota Prius



Hybrid network

Purpose-built storage network

Hybrid power economical car

Purpose-built sports car

Alternative technology

Fibre Channel and iSCSI

FCoE and iSCSI

Real cars, trucks, or SUVs

Minivans and hybrids

Target customers

Ethernet tree huggers

Fibre Channel tree huggers

Upper middle-class hippies and environmentalists

Driving aficionados and enthusiasts

Technology best fit

Server I/O consolidation

Critical applications and storage

Slow lane

Race track

Technology maturity

1 or 2nd generation

7th generation

3rd generation

4th generation

Primary benefit

Converged network that minimizes switches, adapters, and cables

Dedicated network that maximizes uptime, reliability, and performance

Fuel economy, clean air, and carpool sticker

Performance, fun, and even more fun


Unproven beyond edge, layer 8 and 9 complexity, and technology maturity

It's not Ethernet and perceived cost

Subject to occasional road rage and or jokes at your expense

Can't buy groceries and must pay high insurance premiums

on ‎06-21-2012 08:58 PM

Excellent comparison and great article!

In VA, Prii(!) can obtain "clean special fuel" license plates... what clean special fuel exactly is that hybrid burning?  Probably the same special formula I'm running in my Troy Built lawnmower.

on ‎06-22-2012 07:21 AM


I wish all sales presentations included an enjoyable table such as yours :-) +1 on the hilarious scale and making the complex understandable.

by Anonymous
on ‎06-28-2012 02:03 AM

DELL are now selling their blade chassis M1000e without a FC only solution. You get 3 options, converged, pass-through and AG mode only FC. Doing converged networking sounds great in principle but there is more involved than the technology. It requires mature internal processes to enable seamless operational working between the comms and storage guys. If FCOE is being implemented as an interim step towards iSCSI, then I submit you should be going straight to iSCSI anyway. Take up on FCOE has not been tremendous, FCP has at least 10 years of life (in my opinion) and iSCSI appears to be the most interesting candidate at the moment. Cloud offerings are certainly adding towards the requirements of a converged networks.

Thankyou for the article I enjoyed reading it especially the table at the end.

EDIT: After further discussion DELL have now confirmed that the 5424 IO module (FC only) is still available on the M1000e chassis.

on ‎07-27-2012 10:43 AM


Just a minor point on your post. If I understand your comment correctly, "... without a FC only solution", the M1000e does support AG mode, or Access Gateway mode. AG mode uses native Fibre Channel but without the need for a Top of rack or embedded Fibre Channel switch with the consumption of a Fibre Channel domain ID. Instead, a core FC switch provides the Fibre Channel services for the AG mode switch.

I agree with your advice of avoiding FCoE if your final destination is iSCSI.  This avoids learning Fibre Channel and how to manage it since iSCSI does not use the Fibre Channel protocol.  Although often overlooked, iSCSI is one method of "converged networking" relying on layer 3 (TCP/IP) instead of layer 2 (Ethernet w/ DCB) to create a lossless connection to storage.

by Anonymous
on ‎08-09-2012 11:35 AM

As my EDIT points out, DELL have now confirmed the BladeCentre 5424 SAN switch IO module is still available on the M1000e chassis, so from our point of view the issue has gone away since we went for the 5424.

I am familiar with AG (using NPIV) mode and while it does have it's advantages, there was one disadvantage for us, mainly that in AG mode you cannot have targets and initiators on that AG mode only IO module, you'd have to connect your targets on your main (or TOR) SAN switch.

I am more familiar with FC than iSCSI, but we are actively looking at iSCSI as a future transport, however we do have a lot of investment in fibre and also own all our dark fibre. I can see how iSCSI would be attractive to green-fields but that's not the case in our envirnment, however, convergence (if it happens) will ultimately put iSCSI in front of our considerations; just not now.