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By Bill Henderson, Principal Solution Architect, QLogic


In many of his previous SANbytes blog posts, Jason Blosil has provided key findings and industry trends which have clearly demonstrated that a rising tide has lifted FCoE (Fibre Channel over Ethernet) as an emerging new standard. Invited to be a guest blogger for SANbytes, I am happy to concur with Jason’s findings! FCoE is now a leading technology in the data center trend of consolidating the network. FCoE provides a direct mapping of Fibre Channel onto Ethernet and enables Fibre Channel traffic to be natively transported over Ethernet networks.


Puzzle_3_HiRes.jpgWhen deciding on implementing an FCoE solution, you have two methods of CPU processing available to you: a software initiator or a hardware offload engine.  The real question you have to ask yourself when evaluating each of these options is, “Which device do I want to do the work?” Or more specifically, where do you want the processing of the data to occur - on the server’s CPU or on the hardware offload engine residing in the FCoE converged network adapter (CNA)? Software initiators allow you to leverage the benefits of FCoE SANs using cost-effective 10GbE NICs with the servers running the CPU cycles, while the hardware offload engines on the FCoE CNAs are designed to process the CPUs, thus freeing up the server’s cycles.  In this discussion, I will focus on considerations for hardware offload technology and why it might be your new best friend if you have data center virtualization objectives and are considering future upgrade paths.  


What’s virtualization got to do, got to do with it?

You might ask why I’m bringing virtualization into this discussion. Virtualization has tremendous value and its benefits are unquestionable – increased efficiency, data center consolidation, and simplification - just to name a few.  With virtualization, it is important to consider one component of the hardware that is especially getting its work cut out for itself, and that is the physical server(s). Specifically, there are two important performance considerations when it comes to virtualization:


  1. Increased density of applications per physical server
  2. The addition of a virtualization layer


Both will require increased I/O performance from the physical servers and the CPU horsepower to efficiently scale VMs and provide the I/O bandwidth needed for enterprise applications. Add to that the additional burdens on the server, such as additional storage requests, and it can take a real toll.  Instead, why not offload these performance demands to a Converged Network Adapter with a full hardware offload engine of FCoE, iSCSI and TCP-IP network stacks? To put this into perspective, consider how a video card is used in a personal computer for gaming: it offloads the video processing from the CPU. Gamers (I know some of you out there must be fellow World of Warcraft or Call of Duty fans!) are well aware of the advantages of offloading the video processing and using graphic adapters to conserve all available CPU resources for the video game itself. Advantages of the video card include vibrant high-definition images, and, most importantly, CPU acceleration to support the most performance-hungry gaming applications (and I am not just talking about Tetris or Ms. Pacman here). This approach is similar to a hardware offload engine.


Virtualized environments also often need to share a converged network among multiple types of workloads, all with different business-related priorities. Support for industry standards such as N_Port ID Virtualization (NPIV) integration is used in virtualized environments, allowing multiple Fibre Channel initiators to occupy a single physical port, easing hardware requirements in Storage Area Network design, allowing for simplified management and realizing overall cost savings.


Investing in your todays and tomorrows.

One other topic to consider when researching FCoE implementation options is a subject we are all aware of: investment protection. How can investment protection be achieved with FCoE CNA technology?


As mentioned in previous SANBytes blog posts, FCoE, whether with the software initiator or the FCoE CNA, brings the benefits of I/O consolidation and efficiencies while preserving current IT investments by working seamlessly with existing Fibre Channel and iSCSI knowledge and management tools which can be applied directly to FCoE.  FC concepts such as WWNs, FC-IDs, LUN masking, and zoning still apply.  This technology is also compatible with existing FC and iSCSI drivers and managed applications that are currently deployed in millions of systems.  Therefore, a full forklift upgrade is not necessary.


An additional benefit of FCoE CNA technology is that you may decide not to use FCoE immediately and instead utilize 10GbE networking in your data center. FCoE CNAs can support this and maintain an iSCSI-only network configuration.  However, when the time comes to up-level to hardware offload FCoE CNA technology, you can simply change the FCoE CNA to FCoE networking.  With FCoE CNAs you have the capability to start with iSCSI technology, confident in the knowledge that you can seamlessly transition to FCoE CNAs when the time is right, without a complete switch and replacement of your networking adapter investment. 


Hardware offload FCoE CNAs - Giving your servers and pocketbook a much needed break. 

Overextending your server’s CPU cycles - which can often be a result of virtualization - may cause you to pause and consider if you are overextending your servers and the CPU processing they can handle, potentially burning them out long before their expected life cycle. And what about your hardware investment? Will it work with your current hardware while having the capability to support your future requirements?  If you are considering FCoE CNAs with a hardware offload engine, you are headed in the right direction.  The benefits of converged networking are not just a promise to be fulfilled in the far-off future - they are available now and realizable today.


A great resource: QLogic's NetApp partner page describes more fully how our two companies work together.



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