Storage Networks

The Biggest Loser: The Worldwide Data Center SAN Challenge

by Scott Shimomura on ‎01-09-2014 09:24 AM - last edited on ‎02-19-2014 11:37 AM by (6,379 Views)

Weight and size matters in the data center.  As we speak, there’s an obesity epidemic taking place in the data center that has the potential to challenge the health and well-being of data centers throughout the world. In the networking world, there’s been a steady increase in weight and rack sizes, leading to unhealthy consequences like decreased reliability, increased complexity, and higher requirements for power and cooling.

This week’s contestant, the Cisco MDS 9710, hails from Tasman Drive. Over the past couple of years, the MDS 9710 has had the opportunity to train under the guidance of the Brocade DCX 8510 with Gen 5 Fibre Channel. The DCX 8510 has been the market leader and industry role model for data center directors since its introduction in 2011. Its efficient and powerful design has raised the bar for reliability, performance, and scalability.




 The MDS 9710 finally emerged from training and made its data center debut in April, 2013. Curiously in the transition between MDS generations, the MDS 9710 went down the design path of more complexity and fatter is better…

At the weigh-in, the MDS 9710 tipped the scales at a whopping 415 pounds, 40 pounds more and 144 ports less than the previous generation MDS 9513. It also grew 6 inches in depth, now measuring a massive 34 inches deep.

The MDS 9710 was run through a series of challenges to find out whether it is fit for deployment or needs to go back to the drawing board. The Brocade DCX 8510 with Gen 5 Fibre Channel was used as the benchmark for ideal design.

Challenge #1: Weight and Size

Weight and size are indicative of design efficiency and system complexity. In this case, less weight and smaller size equals more efficient use of space and more simplicity.





Results of Challenge #1:  Cisco MDS 9710 Fails

The MDS 9710 is an unfortunate example of data center obesity at almost twice the weight and nearly 50% greater in size (depth) than the DCX 8510. The MDS 9710 requires special handling with heavy-duty hydraulic lifts capable of handling upward of 500 pounds and racks capable of holding its excessive size.

Challenge #2: System Complexity Challenge

System complexity is a function of the total number of assemblies (fabric cards, power supplies, fan modules, etc).  The overall serial reliability of a system decreases as the assembly count increases. While a system can be made highly available through redundant assemblies, this will lower overall system serial reliability due to the additional number of assemblies.





 Results of Challenge #2: Cisco MDS 9710 Fails

 By definition, a director-class switch requires redundant hardware. Adding additional redundant hardware assemblies come at the expense of lower system reliability and additional complexity. It’s a tradeoff that has little value based on the incremental improvement in availability.

 Challenge #3: Component Complexity Challenge

 Component complexity is a function of the total number of electrical components (ASICs, integrated circuits, transistors, etc.) on an assembly. Nobody says it better than Cisco in describing the relationship between the number of components and spacing between the components as it relates to reliability and heat dissipation (at 22:25 ), “… that the more components you have on a board, the more failure points that you have. Any good design is going to try and limit the amount of components here and give you a lot of nice green space…”





 Results of Challenge #3:  Cisco MDS 9710 Fails

Using Cisco’s definition, the MDS 9710 port blade has significantly more components and much less green space than the DCX 8510 port blade. Given the number of heat sinks, it’s also likely drawing more power and generating more heat, both contributors to lower reliability.

Final Verdict

Rather than adopt the training provided by the Brocade DCX 8510 with Gen 5 Fibre Channel, the MDS 9710 turned out to be an overweight, oversized, and over-engineered product.  Cisco designed the new director with the intention to drive new customer benefits, but does it?

 Reliability and availability continue to be the most important attributes of why customers continue to buy Fibre Channel technology. Cisco makes the dubious claim that the MDS 9710 is “the industry’s most reliable storage director”. However, based on the results, it’s clear that the MDS 9710 failed in every challenge. Reliability is proven over time in the data center, not on paper. Even on paper, it’s is obvious that their system has not been designed with high reliability in mind.

 Final Recommendation: Brocade DCX 8510

Clearly, if you are considering new storage infrastructure or replacement of legacy SAN technology, the Brocade DCX 8510 with Gen 5 Fibre Channel should be at the top of your list, especially if reliability and availability are important to you. It is an efficiently designed, elegant, and time-tested director that is purpose-built for data center storage. In addition to hardware design advantages, the DCX 8510 with Fabric Vision software technology will further enhance reliability and availability through advanced monitoring, management, and diagnostics.