It’s pretty traditional to start the year looking at what will be prevalent in the coming 12 months. In this opinion article, I will discuss whether we’ll see the prevalence of iSCSI or FCoE and what we can expect, looking back this time in 2011.
History and Background on iSCSI
iSCSI as a concept was first developed by IBM in 1998. With work from Cisco, a first version of the iSCSI standard was presented to the IETF in 2000. Today we see iSCSI implementations in enterprise storage arrays from the major vendors, from mid-range storage array manufacturers and in virtual appliances. The iSCSI initiator (the host component for making connections to an iSCSI device) is standard in major operating systems such as Windows and Linux. In fact, some vendors like HP/Lefthand and Dell/Equallogic make a virtue of deploying their technology as iSCSI only solutions.
However despite the ubiquitous nature of the iSCSI technology, I don’t think the adoption level is particularly prevalent in the majority of enterprise and mid-range environments, with fibre channel remaining the dominant player.
History and Background on FCoE
By comparison, Fibre Channel over Ethernet is a relatively new technology. In fact, development to ratification has only taken two years and was approved in June 2009. FCoE enables the fibre channel protocol to be passed over 10Gb Ethernet natively. This is a distinct difference from iSCSI which relies on using the TCP/IP stack for communication. As FCoE is so new, it isn’t widely adopted or supported by vendors today, with notably Cisco, EMC and Netapp being the main leaders in offering products or announcing future support.
Why iSCSI Has Failed
It’s a bold suggestion, but I personally think iSCSI has failed to live up to the hype surrounding its development. Although iSCSI is cheaper to implement and support, Fibre Channel remains the dominant force in storage networking today. Why is that? It’s a question I’ve answered many times, there are a number of reasons:
- Legacy of deployed technology. Fibre Channel became entrenched in storage architecture before iSCSI arrived on the scene. Many organisations made investments in skills and hardware, which once established made FC the de facto protocol for storage networking.
- Hardware interoperability. iSCSI and Fibre Channel don’t inherently work together. As far as I am aware, Cisco were the only major vendor to offer a product that had any kind of FC/iSCSI bridge functionality. This makes the two protocols pretty distinct and there’s no benefit to running multiple disparate storage protocols within the same environment.
- The Cultural Issue. Fibre Channel devices have typically been managed by the storage team. iSCSI and IP are the domain of the networking team and “Never the Twain Shall Meet”. Even though iSCSI is recommended to have a dedicated infrastructure (which should still work out cheaper than FC), the hardware configuration and deployment would be managed by the network teams. There are very few instances I’ve seen (and certainly not viable ones) where Storage and Networks work in harmony.
Why FCoE will Succeed
Where iSCSI has failed, FCoE will surely succeed. As a protocol, it offers more opportunity of integration between “traditional” fibre channel and FCoE. In fact, hybrid devices are already available from the market leaders, Cisco and Brocade. FCoE is being built into the hardware designs of integrated solutions from Cisco and Acadia. Solutions from HP and IBM will have to offer the same functionality. The whole culture issue will be removed by the deployment of end-to-end architectures. Perhaps in addition the two teams may just have to learn to live with each other.
A Mixed Landscape
I think in the next 12 months we’ll see the gradual adoption of FCoE as legacy FC environments come up for renewal and the choice between 10Gb/e and 10G FC has to be made. There will no doubt be a lot of confusion as to which protocol suits large environments best. My negativity towards FCoE has been based on exactly what benefit FCoE would provide in large environments over FC. After all, cost is hardly the issue when FCoE CNAs are still so expensive. Overall, iSCSI will be the loser and will be relegated to mid-range and SOHO solutions where it does an excellent job. In 12 months time, we’ll be discussing the battle between FCoE and FC and iSCSI will be an also ran.