Fibre Channel Over Ethernet: From Fee To Free

alphadogg writes "With demand for Fiber Channel over Ethernet (FCoE) more sluggish than vendors had hoped, 10 Gigabit Ethernet switch and adapter makers are making it available for free. FCoE is a standard driven largely by Cisco to converge customers' data center LAN and storage fabrics with 10G Ethernet. Industry heavyweights Intel and Brocade are among those now giving away FCoE capabilities. There are several factors prompting vendors to slash FCoE prices or stop charging for it altogether, including market indifference; technological immaturity; competing alternatives, such as virtualized Fibre Channel and Ethernet I/O; the recession; and vendors looking to drive switch volumes. 'When FCoE first came out there used to be a fairly large price premium,' says Alan Weckel, director of Dell'Oro Group. 'Cisco had to give it away for free to drive switch volumes. Users were not adopting as rapidly as thought or that Cisco had hoped for.'"

Comments

Too late

[Anonymous Coward]

As network fabric bandwidth continued to increase and latency decrease, FCoE appeared to be a last ditch effort to plug the steady trickle of customers from the highly expensive FC over to the much cheaper to deploy iSCSI. I'm sure the thinking was that by making it routable and with the same semantics as existing FC installs, it could accomplish that task. However, I'm also thinking that in most situations, where there's little to distinguish between iSCSI and FCoE other than the now almost commonplace on-NIC hardware iSCSI acceleration, it's a case of too late.

Re:Too late

[Junta]

Actually, FC isn't routable. FC over *ethernet* has no ip and no provisions to span gateways. The *theory* is that FCoE has fewer layers allowing for higher performance, but it's rare for that difference to be realized in cheap ethernet fabrics (the whole point of FCo*E*) and even rarer to matter relative to storage device performance limitations. iSCSI is much easier to manage with fewer limitations and gets some nice things from being over TCP whether FCoE people will admit it or not.

When FCoE first came to market, vendors had dollarsigns in their eyes with thoughts of extorting customers with FC pricing strategies using 'just' ethernet. You saw people trying to do per-port FC enablement licensing BS and other stuff unheard of in ethernet land.

If FCoE is going to exist long term, it will be as a 'freebie' alternative to iSCSI or as a convenience to build large SANs without a lot of FC switches and HBAs but using existing FC enclosures.

Re:Too late

[guruevi]

I think he meant that FC is not routable as the standard IP protocol is unless you buy expensive and proprietary solutions (as you call it, a hack).

  iSCSI has the advantage of being able to sustain a packet loss while FCoE can't stand it. FCoE is thus only possible over a small fabric (eg. 1 stack of dedicated switches) while iSCSI can be mixed with other traffic without sustaining any issues. Off course, some people using iSCSI can't sustain any packet losses either (because of latency - eg. streaming video and live video editing) and don't understand that Ethernet is not built for that kind of load - network engineers don't care about packet losses and hope the transport layer will fix them, storage engineers can't have any packet losses and the transport layer relies on it.

That being said, FCoE is similar to ATAoE, never widespread because of it's iSCSI cousin and those that ended up using it, might as well just used a true FC (or Infiniband) fabric.

And still, no one buys it.

[7213]

FCoE...

A solution in search of a problem. 10GbE ethernet is really very nice. FC (and FCoE included) have a history of poor vender interop.

So by using FCoE you get the worst of both worlds, 10GbE with vendor lockin at the storage level....

So... NFS anyone (or I guess iScsi)?

Only time i've ever used FCoE was as a WAN tunnel link for asynch rep.... not seeing any other value for this anytime soon.

Re:Forgive my ignorance...

[quickOnTheUptake]

Apparently the latter. "Since classical Ethernet has no flow control, unlike Fibre Channel, FCoE requires enhancements to the Ethernet standard to support a flow control mechanism (this prevents frame loss). . . . Fibre Channel required three primary extensions to deliver the capabilities of Fibre Channel over Ethernet networks: -Encapsulation of native Fibre Channel frames into Ethernet Frames. -Extensions to the Ethernet protocol itself to enable an Ethernet fabric in which frames are not routinely lost during periods of congestion. -Mapping between Fibre Channel N_port IDs (aka FCIDs) and Ethernet MAC addresses." --Wikipedia

It's all about what the swich is capable of

[sirwired]

Your plain-vanilla 10GbE switch does not have the flow-control bits required to make Ethernet lossless; without essentially lossless traffic, SCSI/FC perf goes in the dumpster. (0.03% packet loss == approx. 50% performance cut.)

In addition, there must be at least one switch in the VLAN that can provide FC services, such as zoning, address assignment, name services, etc.

Re:Duh

[afidel]

Actually FC has an inherent disadvantage and that is they ship about 5% of the ports per year that Ethernet does and so all their R&D has to be spread over 1/20th the ports. The vendors all realized this about 5 years ago and so they started on FCoE to spread their R&D budget over the much larger Ethernet ecosystem. I believe 16Gb FC will be the last standalone standard and that after that they will piggyback on Ethernet for 40Gbps and 100Gbps speeds. Speaking to industry insiders at Storage Networking World it's obvious that the days are numbered for standalone FC.

As to your claims that 10Gb FCoE is slower than 8Gb FC for throughput that's rubbish as the framing overhead for FCoE is nowhere near 20% and they are both lossless protocols, for latency it may or may not be true depending on implementation.

I will admit though, performance is impressive....

[Desmoden]

With no tuning (other than Jumbo frames for FCoE) I was able to get 9.7Gb/s using FCoE over 10Gb ethernet.

While 16Gb FCP/FC is around the corner, you will be able to run FCoE over 40Gb and 100Gb ethernet in 2-3 yrs. (at MUCH $$)

Keep in mind however, iSCSI has been around for over 10yrs now. These things take time to grow, mature, attach.

So lets wait a few more years before declaring anything dead or alive =)

And keep in mind, FCoE is not meant to replace FCP/FC, its meant to fix what is keeping iSCSI from doing better.