It’s a common fallacy of Storage Experts is that FCoE will “rule the world” and that Storage equipment has some special magical properties that makes it different from any other technology. Chris Evans posted the most common fallacies iSCSI is the home protocol
Let look at the most common mistakes that Storage people make.
- 1 The Four Common Falsehoods of Storage
- 2 iSCSI is good enough, Customers buy good enough
- 3 Networking is reliable enough
- 4 Standards, Certification and Unicorn Tears
- 5 FCoE is not the ONLY choice
- 6 FCoE is a migration technology
- 7 FCoE is the only solution
- 8 What Networking still doesn’t have
- 9 Wrapping It Up
The Four Common Falsehoods of Storage
Chris’s post outlines them, and they are quite common. Here is my list:
- The Networking people don’t know what they are doing and aren’t reliable
- FibreChannel networks are a controlled environment
- Networks use cheap and non-standard/non-certified / open-standard equipment, Fibrechannel is expensive, certified and therefore inherently better
- FCoE harmonises Storage and Networking at the Ethernet layer, and this is the ONLY possible solution that can work
OK. Let’s take these on. Lets start with an understanding of Good Enough versus Overly Perfect.
iSCSI is good enough, Customers buy good enough
The bulk of the Storage industry believes that iSCSI isn’t capable enough. Having been force fed this marketing hype for the last ten years, it pretty well entrenched as mindset.
And yet, entire swathes of the Storage market are using iSCSI. Left Hand and EqualLogic, for example, have demonstrated that customers don’t always want FibreChannel. They don’t need standards, and that good enough works.
Now, if you don’t believe that people will buy good enough then perhaps the most powerful example of Good Enough in IT is Microsoft Windows. Even though it isn’t particularly good, or fast, or cheap customers continue to buy and implement because it’s good enough.
Networking is reliable enough
It’s absolutely true in my opinion that today’s Networks are not ready, as a general concept, to carry storage data. There are good reasons for this.
- Data Network protocols are designed to be robust. Therefore the tolerance of low cost networking is very high. Storage Protocols are not designed to be robust and therefore tolerance of the networking and open storageis very low. The fault here is the FibreChannel standards are quite poorly designed, or perhaps, narrowly designed with liimited flexibility.
- Data Networks spending is about 30% the cost of an equivalent Storage network. And if I had spent the same money, the Data Network would have the same performance capabilities. For example, in a Cisco environment, I would implement Nexus 7000 instead of Catalyst 6500, with all the fancy go-fast bits, at a price premium of 300%. Pointing out that Data Networks are not as reliable as Storage networks is the same as pointing out the nose on your face.
- Storage network are really small. A few hundred ports, maybe a thousand or so in some cases. (and some more exceptional cases). Data networks have several orders of magnitude more ports, and vastly more complex performance requirements. Scaling FC could be solved, but, why bother ?
- Data Networks have vastly more complex requirements that a Storage network. A storage network with FC is focussed on a single task whereas a Data Network is sophisticated in it’s ability to handle a wide range of variably functioned loads, tasks, applications and user needs. A storage network can only manage a single thing.
- Data Networking people haven’t needed to deliver the capabilities and service levels that FC forced you to choose. But we are already training and moving to new designs that deliver the same outcome. Look at the Nexus 5000, which handles iSCSI, FC & FCoE equally as well as VoIP, SAP, Oracle and other mission critical services.
My point here is that Data Networks could be more reliable and perform to the same level as legacy FC Storage but historically, people have taken the “Good Enough” choice.
The good news is that Data Centre networks will be designed and engineered to the same level as Storage networks have been, and that will deliver the results that are needed.
Standards, Certification and Unicorn Tears
Let remember back to IBM mainframes and the after market addons that required IBM to certify each and every products to be compliant with their hardware and software. It worked for a while, but customers rapidly left Mainframes for new technologies when they became viable.
Claims that Fibre Channel networks are great because “they are expensive and approved” do not match with the reality of the marketplace and history. Customers will rapidly move to other technologies that show they work well enough. Because the Storage market is so early in the technology cycle, the idea of ‘blessing products’ with validation or certifying that this product has been bathed in unicorn tears, is just a passing phase. Eventually you will arrive truly open standards that interoperate properly and correctly without requiring special techniques.
How do I know this ? Because that’s what Data Networking did in the late 1980′s. Hark back to events such as ‘Interop’.
Note: IBM Mainframes still exist today for those use cases where they are excellent, and the future of storage will still have use cases where FC & FCoE make sense, but in the long run people will spend the bulk of their money elsewhere.
FCoE is not the ONLY choice
Read it and weep, IT ISN’T. There are several choices, including iSCSI, FibreChannel, Infiniband and new protocols that haven’t yet been developed. FCoE is the current choice, where previously the Storage industry had declared that several other protocols
Think of FICON, ESCON, iSCSI (in the early 2000′s this was THE storage protocol), Infiniband and today it’s FibreChannel. Tomorrow’s choice is FCoE, and after that ?
After that it’s probably iSCSI, because the 802.1 DCB standards solves the networking problems that stopped iSCSI from large scale acceptance. Or possibly a new protocol that doesn’t use TCP and just encapsulates the data in an IP packet as a block thus removing the processing load of the TCP header.
FCoE is a migration technology
Because FCoE takes the existing FC installed base, and neatly removes all the objections of the storage industry to connecting to an Ethernet network, it sets up the Data Centre for a migration away from FibreChannel. That, ultimately, is the primary purpose of FCoE. FCoE is not the end point, or the final protocol for storage, it just the next step in a rapidly maturing industry.
The Storage Industry appears to be stuck in the past. They have failed to adopt iSCSI in 2002/2003, they failed to adopt Infiniband in 2005/2006. They kept banging away at making FibreChannel work, until it actually did.
Networking isn’t exactly a saint here
Lets remember that Networking has had the same pains and we’ve been through all this before. Token Ring and FDDI were also superior technologies to Ethernet. I wouldn’t agree that Ethernet isn’t perfect, far from it and many years of banging away at making it work have produced a protocol that works. But it’s flaws are many, it cannot readily scale and has a number of inherent limitations that will take years for silicon and software to work around (RDMA over Ethernet is a case in point).
iSCSI works when correctly designed
From a networking perspective, iSCSI has some quite specific design factors that make it difficult to perform at high speed. However, it is much more robust and capable than FCoE and will work in a much wider variety of Data Centre backbone that FCoE ever will. This is what makes it especially attractive to SME deployments.
iSCSI needs to be updated too
iSCSI will always be performance limited since it uses the TCP protocol as the transport mechanism. At some point, someone is likely to develop a new version of iSCSI that run either over UDP (as NFS does) or directly encapsulated in IP as an IP-native protocol.
This type of change would improve the iSCSI performance matching FCoE. However, I think that development of this new protocol won’t be possible until the Cisco FCoE marketing effort finally drives DCB into the data centre and actual deployment. That is, any new developments in storage will stalled until the current changes around FCoE either fail, or reach some level of acceptance.
FCoE is the only solution
It isn’t. Infiniband is significantly cheaper, and is much faster. Whether it can impact the market without a a billion dollar marketing program ‘a la Cisco’ remains to be seen.
And Storage over IP still hasn’t updated to modern concepts. Choosing to move block storage data over TCP isn’t a great idea.
FCoE suits Cisco and Brocade
FCoE as a solution is a marketing move by Cisco that is now followed by Brocade. The networking industry has been marginalised with dumb switches and dumb networking for a number of years. Cisco has constantly attempted to develop products that promote Smart Networks and failed thus leaving them in a commodity market. This is marked by the rise of HP ProCurve products and other merchant silicon plays such as Arista. Equally, it is also marked by the failure of Nortel who were unable to compete.
Both Cisco and Brocade need a ‘smart network’ so that they can add value to their products and not be marginalised into a commodity market such as the Intel servers markets. Because FCoE requires the switches to have significant participation in the storage layer, it’s a way of developing another ‘Intelligent Network’.
What Networking still doesn’t have
The biggest missing element of a modern data network is decent, workable management tools. I constantly battle with the software that manages my network and no product today is up to the task of automation, service management and operational control of a data network. But the focus on the Data Centre appears to be changing this. FCoE mandates the use of management platforms that provide effective tools. These tools are going to have a large impact on the networking industry.
Wrapping It Up
So FCoE is a transition technology that merges storage into an IP network. It may take a few years, but Storage over IP will eventually dominate. The data networks of today are capable, but we need to develop new management platforms and just a few new skills. The addition of serious cash to upscale our network products will see Data Networking deliver a service far better than a legacy FibreChannel system, one that is flexible, multifunctional and better value for money.
So don’t pre-judge technologies like iSCSI. Whether you like it or not, converged Storage and Data Networks will happen. I don’t really mind that another service is coming onto my network, it’s not much different from the ones that we already have in terms of reliability and performance. A few changes here and there, and Data Networking will be up to the job.