Continuing from my previous article which introduced Converged Enhanced Ethernet, lets look at how we can converge our storage and data networks and have a single fabric in the data centre.

The value of HBAs

In this plan, your network adapters and drivers (HBAs) must respond to these flow control messages to stop or slow data transmission so as to avoid congestion in the network and subsequent packet loss. Thus HBAs will becomes critical to the success of iSCSI or FCoE because they will need to have large and smart buffering schemes to be able to handle the data pumping. I have talked in previous articles about the value of HBAs in your servers and this is another example of their value.

The value of a single Network fabric

The current storage network strategy means that there are two networks in our data centre, Fibrechannel and Ethernet. Many people are co-opting this strategy for their iSCSI backbones by creating a second network dedicated to IP Storage.

Unlike using TCP/IP to perform QoS, where the QoS mechanisms are not will suited to storage traffic, CEE will deliver a zero to low loss switching backplane to iSCSI and yet offer support to a number of other applications. The option for single, unified Ethernet fabric in the Data Centre is very real.

Further, we will still have native IP support for WAN for inter-Data Centre connections when needed without extra actions or work. (Unlike Fibrechannel, which will still need FCIP plus FCOE / FC to perform inter-Data Centre connections).

Lets merge these together

Not so long ago, Telephony was migrated to an IP network. It was widely agreed that voice could never travel across a packet network because delivery was not guaranteed, delay / jitter was a problem, the sky would fall down etc etc.

The argument against merging storage and data networks is a reasonable statement with the Ethernet technology we have today. However, Converged Enhanced Ethernet is expected to deliver (in time) a single Ethernet fabric for our entire data centre.

Consider the Brocade approach “FCoE is Fibre Channel, not legacy Ethernet.” – Page 62 – Brocade Tech Day briefing here. This means buying super special sauce switches from Brocade, that support FCoE / FC. It hard to perceive that we can build a unified fabric using these products. At best, they are a “transition” or short term fixit for the Fibrechannel problem.

Building a Unified Fabric

So there are several things that have to happen. Lets be real, and think about what to look for.

First the CEE standard needs to be completed by the IEEE. Second, the vendors need to announce Ethernet switches that support CEE. Look for Cisco and Brocade to be early to market (because they want to force customers to FCoE), but keep an eye on Juniper, Force 10 and Woven who can all use this disruption in the market to take a new position in the market and attack Cisco’s dominance.

Third, look for quality HBA’s and their software drivers. Fourth, look at the integration required between the Network and Server Teams to seamlessly deploy this new network strategy.

When do you think it will be ready

I would _guess_ that CEE will be done by 2010 (OK so there will be pre-standard stuff around like the Cisco Nexus 7000 / 5000, but not many people will buy that). Because this is a market disruption point, I would expect the vendors to have products out quickly, particularly Juniper. So you should be thinkinh about deployment in 2011. Thats only _three_ years away, or a single investment cycle.

Conclusion

So this sounds like a long way off, but we are already getting the marketing hype from Cisco, and I guess Brocade will not be far behind. We haven’t heard much from NetApp / EMC / HP / IBM so its not clear what might happen if they decide to move down a different path.

In the mean time, the focus should be to stick with iSCSI and that will be a viable, long term, technology. When you need to scale to muligigabit performance, new technologies will be there to make it happen. Reliable, Scalable, and Easy to Use. Thats what we want, right ?