I must admit that I have been an sceptic about FCoE since Cisco introduced it in 2008 up until recent times. With limited storage knowledge and background, I though that going forward NAS would prevail for most environments, and iSCSI would be the winning option for block based storage needs. Now I think there's going to be space for all of these, but FC has a better chance when dealing with block storage.
Why am I changing my mind? Well, a bit more knowledge, but also recognizing the facts. Overall FC market is still growing. Some analysts estimate 9-10% Y/Y growth at the end of 2010 for total FC market in vendor reported revenue. And it is remarkable that FCoE is becoming a larger part of that market. Depending on reports, it would now be up to 10% of the total FC market (considering adapters, switches and controller ports). And the really important thing is that this is more than doubling its contribution to the total market vs one year ago.
Those are some facts. About knowledge, I know recognize that FC networks bring not only stability and performance required for Tier 1 applications and mission critical environments, but also offer management over the SAN that is unmatched by other SAN protocols. The problem for many customers was that deploying FC was prohibitively expensive: the need to deploy a completely separate network, (which usually had to be design-stamped by the storage vendor) and the lack of FC interfaces on low end (and even mid-range) arrays made it impossible for small and mid-sized organizations to even consider it.
This is where I see a new angle now. FCoE is going to make FC as ubiquitous as Ethernet, and almost as affordable.
Customers jumping on iSCSI would normally pick on using the same switches for LAN and iSCSI (perhaps dedicating ports for the latter, and certainly should be dedicating separate vlans, subnets, etc.). Server side? Just another pair of GE ports. Usually not adding much to the cost if you were considering quad NIC cards on top of whatever comes as LOM.
FC would have added a lot. A pair of 4Gbps ports would represent an HBA or about $2K, and then you had to add separate dedicated Fabric switches at the access layer.
Well with FCoE, you put FC at the same level as deploying iSCSI for many people. First of all, FCoE now comes standard in NICs (CNAs) from many vendors, including Emulex, Qlogic, Intel, Cisco or Broadcom. Intel's approach of OpenFCoE adds no cost to deploying just 10GE, and renders the price per port to about $400 range. Such CNAs are already certified by most relevant storage vendors including EMC and NetApp. Vendors which, btw, are also adding FCoE support to their mid-range and high end arrays.
Now the network piece. 10GE ToR ports are about $500-600 a port. Cisco solutions there, thanks to FEX approach, allow to deploy a very cost effective 10GE access network, where all ports can support FCoE. So, in essence, you are at the same position as with iSCSI now: can use affordable ports at the server, have support for most common OS, can use the same network infrastructure, and can pick from multiple storage vendors. Nice thing on top? You can get management tools like CIsco's DCNM to give you visibility of LAN and SAN traffic (which you do not get with iSCSI).
Bottom line, I think FCoE is making FC easier and cheaper to deploy, so I expect more and more customers to consider using this technology, on top of those already using FC to adopt FCoE as well (using less power, lower capes, simplified operations, etc.).
Of course there is space for NAS deployments as well, and iSCSI will continue to grow, but I think FCoE makes FC much more competitive as a technology than it ever was for deploying a SAN.