For those of you who are thinking of rushing into FCoE and the Cisco Nexus switches you might want to think again. There are a few people coming out against FCoE and asking why is anyone bothering ? Should I be putting it in my design portfolio ? Is FCoE a done deal just because Cisco is throwing it weight around, or does it have merit.
In fact after some research , there are so many negatives I had to put them in multiple parts.
A very old posting (from Aug 29 2007!) pointing out the FCoE was waste of space. Its an erudite and robust article covering both sides of the debate, with FCoE definitely losing. Catfight Over FCoE.
Reasons not to use FCoE include:
* FCP endpoints are inherently costlier than simple NICs ñ the cost argument (initiators are more expensive)
* The credit mechanisms is highly unstable for larger networks (check switch vendors planning docs for the network diameter limits) ñ the scaling argument
* The assumption of low losses due to errors might radically change when moving from 1 to 10 Gb/s ñ the scaling argument
* Ethernet has no credit mechanism and any mechanism with a similar effect increases the end point cost.
* Building a transport layer in the protocol stack has always been the preferred choice of the networking community ñ the community argument
* The ìperformance penaltyî of a complete protocol stack has always been overstated (and overrated). Advances in protocol stack implementation and finer tuning of the congestion control mechanisms make conventional TCP/IP performing well even at 10 Gb/s and over.
* Moreover the multicore processors that become dominant on the computing scene have enough compute cycles available to make any ìoffloadingî possible as a mere code restructuring exercise (see the stack reports from Intel, IBM etc.)
* Building on a complete stack makes available a wealth of operational and management mechanisms built over the years by the networking community (routing, provisioning, security, service location etc.) ñ the community argument
* Higher level storage access over an IP network is widely available and having both block and file served over the same connection with the same support and management structure is compelling ñ the community argument
* Highly efficient networks are easy to build over IP with optimal (shortest path) routing while Layer 2 networks use bridging and are limited by the logical tree structure that bridges must follow. The effort to combine routers and bridges (rbridges) is promising to change that but it will take some time to finalize(and we donít know exactly how it will operate). Untill then the scale of Layer 2 network is going to seriously limited ñ the scaling argument
Note also that Silvano Gai (of Nouva now acquired by Cisco and chief cheerleader for FCoE) trying to spike the pro-iSCSI debate by pushing some process complaint into the argument about standards. Bad form there.
My favorite bit
The only argument I have heard for continuing any development in the FC protocols at all, whether that development is done at T-11 or at IETF, is to provide the means to wean all the crack addicts in the Global 2000 off of FC fabrics altogether, and as soon as humanly possible. FC SAN is simply the most expensive way to host data that was ever invented. No surprise that it came to market at a time when everyone was suspending disbelief and investing in dotcoms.
I agree completely with this point.
I had a look at a Web site fcoe.com, with lots of nice information. However, it too is owned by Nouva Systems and thus Cisco.
Is there anyone else but Cisco supporting FCOE ?
Note: Apologies for the ads in that screenshot but the Network Solutions whois server is absolutely criminal.