Is Unified Fabric an Inevitability?

Friday, February 20, 2009 in Gestalt, Storage by slowe | 11 comments

So here’s another “thinking out loud” post. This time, I’m thinking about Fibre Channel over Ethernet (FCoE) and unified fabric.

I was going back through a list of blog posts and articles that I wanted to read and think on, and I came across a link to Dave Graham’s article titled Moving a Fabric forward: FCoE Adoption and other Questions. His blog entry was partially in response to my FCoE discussion post. His post got me thinking again.

It seems like anytime someone talks about FCoE, they end up also talking about unified fabric. After having read a number of different articles and posts regarding FCoE, I can see where FCoE would be attractive to shops with significant FCP installations. In my mind, though, this doesn’t necessarily mean unified fabric. Given the political differences in organizations—think the “storage team” and the “networking team”—how likely is it that an organization may adopt FCoE, but not unified fabric? Or how likely is it that an organization may adopt FCoE, intending it to be a transitional technology leading to unified fabric, but never actually make it all the way?

So here’s my question: is unified fabric an inevitability?

(Oh, and here’s a related question: Most people cite VoIP as proof that the unified fabric is inevitable. More so than anything else, I believe VoIP’s success was more a reflection of the rising importance of TCP/IP networking. If so, does that give iSCSI an edge over FCoE? Is iSCSI the “VoIP of the storage world”?)

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  1. Stephen Foskett’s avatar

    Stephen Foskett on Friday, February 20, 2009 at 10:09 am

    I wouldn’t say that a unified fabric is necessarily an inevitability, but I do think that the Data Center Bridging protocols and converged network adapters are inevitable. So whether you want to unify storage and networking or use FCoE, you will definitely have the capability to unify them. And once you have an FCoE-capable network, there will be an inevitable pull towards using it.

  2. Marc Farley’s avatar

    Marc Farley on Friday, February 20, 2009 at 1:00 pm

    Hi Scott, I think FCoE is likely to survive and thrive mostly because iSCSI isn’t getting the same amount of technology and market development. iSCSI is mostly “cooked” and even though there may be the potential to develop it further, nobody seems to have the motivation to do it. The amount of money spent to develop and sell technology matters a great deal. The storage industry is investing in FCoE today.

    Unified Fabric is another matter. This seems to be mostly Cisco’s initiative. If it is slow selling initially and if Cisco’s R&D expenses for it are high and the IT market contracts (as it appears it might be doing) – the question is how long will Cisco continue to invest in it. During that time, competitors may be able to come up with alternative products that don’t require as much investment and are less disruptive. If it turns out to be a big money loser for Cisco by mid 2010, it might not make it.

  3. David Magda’s avatar

    David Magda on Friday, February 20, 2009 at 7:12 pm

    I would think it’s the opposite: I think iSCSI is likely to have a higher market share, mainly for the reason that it’s routable.

    The storage industry may be investing in FCoE, but they’ve already invested in iSCSI as well. NetApp and EMC have targets (as well as Sun in their 7000 line), and initiators are available for all OSes as well as VMware.

    I don’t think it’s going to be either/or, but different people will choose different things for their needs.

    I think things will generally standardize on Ethernet as well, though Infinibad will have a decent minority stake in specialized markets. They’re talking Ethernet at speeds faster than 10Gb, but IB is already at 24 and 96 Gb. Some people need that.

  4. TimC’s avatar

    TimC on Sunday, February 22, 2009 at 9:16 pm

    The real question is, if we’re going to unify the fabric, why are we using ethernet? Why not infiniband? You can run all of the same protocols at about 4x the bandwidth.

  5. Omar Sultan’s avatar

    Omar Sultan on Monday, February 23, 2009 at 2:21 am

    Scott:

    I think unified fabric will continue to gain momentum because of the potential to reduce TCO by simplifying infrastructure and also for the functional advantages of having all your initiators be able to talk to all of your targets.

    That being said, I don’t believe this needs to be an either/or debate. If you fast forward a few years, I think the typical enterprise DC will have a mix of FCoE, iSCSI and FCP. Each has its own place and I think they can happily co-exist the same way FC SANs and fliers co-exist today.

    If customers do not have existing FC SANs and are not good candidates for FC, then, my guess would be they will either go with iSCSI or wait not native-FCoE targets.

    I am not sure I can think of a scenario where I would see a customer deploy a parallel, dedicated 10GbE FCoE network (i.e. deploy FCoE but not as a unified fabric). I am not sure there is an upside for the storage team and I am pretty sure the network team would throw up all over it.

    Omar Sultan
    Cisco

  6. slowe’s avatar

    slowe on Monday, February 23, 2009 at 7:31 am

    Omar,

    Thanks for your response. Given that FCoE is inherently compatible with FCP (to my understanding they are almost identical except for the physical transport), it seems reasonable to me that an organization may deploy FCoE as an extension to an existing FCP SAN but not necessarily move to unified fabric (at least, not initially).

    I’d be interested to hear why you don’t think that is reasonable. Can you share your thoughts?

  7. Nate’s avatar

    Nate on Monday, February 23, 2009 at 12:45 pm

    Is iSCSI the “VoIP of the storage world”? My answer, yes. Let’s look at VOIP for a moment. What makes it great is not that it runs on ethernet, but that it runs on the tcp/ip stack. I don’t think unified fabric has much value to organizations unless the stack is also unified. By running on the tcp/ip stack VOIP could happen with existing network equipment. iSCSI holds the same advatage (you also get routability). To ‘unify’ FCoE you need special (read expensive) network equipment. FCoE almost seems like a gimmick from storage and networking vendors. I can see some value as a transitionary product, but I just don’t see how it stands on its own.

  8. Kosh’s avatar

    Kosh on Tuesday, February 24, 2009 at 7:42 pm

    Hi – I’m the infrastructure architect for a large and nationally recognized financial institution.

    We expect to converge storage and application networks at the fabric layer i.e. Layer 1 eventually – and yes, converged voice & data via VOIP is seen as the strategic forerunner.

    Our next-generation network plans will be 10G end-to-end and we expect to run storage over that, for both OS and data. We already qualify some Silver and Bronze-class applications over NFS and iSCSI with GigE and LACP, and expect to be able to use FCoE in future for Gold-class applications.

    We would expect to maintain separation at layer 2 and above, via further deployment of 802.1q and related protocols end-to-end e.g. MPLS VPNs.

    Our timeframe for this is the next 3-5 years i.e. once the Cisco Nexus has reached the same level of maturity and $/port that made the 6509 so attractive.

  9. Kosh’s avatar

    Kosh on Tuesday, February 24, 2009 at 7:46 pm

    I should add that at a recent storage summit I was speaking with other enterprise infrastructure managers & architects. We had a show of hands on various storage fabrics:

    FC2: Everyone using.
    FC4: Almost everyone using.
    FC8: Almost no-one using it or interested.
    10G: Almost no-one using it but everyone interested.

    Architects don’t always get our way, but that’s the way our informal poll showed us as leaning.

  10. David Magda’s avatar

    David Magda on Tuesday, March 3, 2009 at 9:38 pm

    FCoE may be “inherently compatible with FCP”, but it seems that the switch companies will want you to buy special “Ethernet+FCoE” switches to get a unified fabric. In EMC’s own words: