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High Profit, Low TCO: What is QLogic Switch Independent NIC Partitioning
Don Wake|Wednesday, January 28, 2015
Technical Marketing Manager

In the networking world a happy customer often equates to consistent fast application performance. If our customers always arrived at our doorsteps at exactly the same time demanding exactly the same amount of product then performance consistency would be easy. In networking infrastructure terms the products we sell are really packets of data that deliver our digital products to the customer. Our customers knock on our digital doors or network ports whenever they want and in unpredictable numbers; network utilization can grow and shrink unpredictably.

In addition to the unpredictable nature of network usage tight IT budgets demand that network infrastructure be shared with multiple unrelated customers. One example of this would be a Managed Service Provider (MSP) running a Software-As-A-Service datacenter. An MSP will have many different businesses using the same “front door” so to speak. We need to be able to share network infrastructure, we can't have dedicated hardware for each customer and we need to ensure each customer and application runs at the speed the customer demands. In this type of "Multi-Tenant" and Software Defined Network, network performance can be hard to predict and this is often due to the need to control Total Cost of Ownership (TCO) through shared hardware.

QLogic Switch Independent NIC Partitioning

QLogic offers users of the 3400 and 8400 series adapters a feature called QLogic Switch Independent NIC Partitioning (QLogic NPAR) that was designed to ensure network performance and maximize TCO. At a high level the feature allows the user to take a physical 10GbE port and divide it up into what are called Physical Functions. Each Physical Function appears to the server like any another physical adapter port but with the added user configurable option of setting a minimum and maximum bandwidth on each Physical Function. The feature is Operating System independent and works with any standard Ethernet switch. 10GbE is a lot of bandwidth…sometimes it’s far more than any single application can utilize and sometimes it's not enough. In other words your backup application isn't always going to transmit at a rate of 10 gigabits per second and take all of the bandwidth available on a given port. Also, it is not likely the primary customer application or VM will require the entire 10Gig pipe all the time.

You may want the backup application to take as much bandwidth as "is available", but at the same time you don't want that backup application to prevent your customers from speedily making purchases on your E-Commerce website. In a virtual environment you may want to ensure a vMotion can take as much bandwidth as is available, but not at the cost of slowing down the customer applications running on another VM or in another application running on the same server using the same physical 10GbE port.

In short, you want to ensure your critical applications ALWAY have a defined minimum amount of bandwidth, but when they are not using that bandwidth, yield it to other applications that can use it. Finally, you don't want to make these decisions every day or every hour, network administrators do not have time to babysit the network traffic flow. QLogic NPAR does this work for you.

This idea of "Dynamic Bandwidth Allocation" is at the heart of the design of the QLogic Switch Independent NIC Partitioning (NPAR) solution. This solution is built into the hardware, firmware and drivers that control the QLogic 3400 and 8400 Series adapters. QLogic NPAR is a switch independent and operating system independent solution for the most efficient use of high bandwidth 10GbE connections.

Physical Functions not Virtual Functions

Once partitioning is applied, the server will see 4 PCIe devices at boot time or Physical Functions (PFs). By calling this a PF we differentiate it from the actual "Physical Port".

A QLogic NPAR - PF does not require SR-IOV. A PF is very different from SR-IOV, which are "Virtual Functions" (VFs). This is a critical point to remember – QLogic NPAR partitions are Physical Functions as far as the OS is concerned – not virtual functions tied to an SR-IOV based solution defined by a Linux OS. Even more interesting is that because PFs look and behave exactly like any PCIe device, you can virtualize each PF by dividing it into multiple SR-IOV VFs! This means QLogic NPAR and SR-IOV can be configured together.

Another advantage to this QoS solution being entirely controlled by the adapter in the adapter hardware is that the Physical Functions can be exposed to the server boot BIOS – no Operating System even needs to be loaded to interact with a QLogic NPAR PF. A QLogic 10GbE partition then can be used for remote booting a server and the feature is compatible with Pre-EXecution (PXE) Boot or iSCSI Remote Boot or boot from SAN or FCoE Remote Boot from SAN (8400 Series Adapters).


QLogic's 3400 and 8400 series adapters offer powerful new tools to the network administrator's toolbox. These tools can be used to protect the performance of multiple customer environments simultaneously while sharing physical hardware. The Physical Functions feature allows the same level of functionality across multiple Operating System types and is so flexible that multiple protocol boot support is offered. This solution offers a cost effective use of precious PCIe slots in the server. Physical isolation of traffic types is achievable with one QLogic 3400 or 8400 adapter installed in one PCIe slot, but then partitioned with QLogic NPAR. From a Total Cost of Ownership and management perspective there is a huge savings to the IT department, and a huge performance improvement and Quality of Service guarantee available to the customer. In Part 2 of this series "How to guarantee customer Application performance" we will discuss at a high level what makes this dynamic solution work during heavy network usage and during times of lighter network utilization.

For More Information

Please see these links for more information on these innovative 10GbE Intelligent Ethernet and Converged Network adapters. An excellent use case discussion for VMware and QLogic NPAR can be found in our Solution Sheet: Switch Independent NIC Partitioning and VMware Virtual Environments. A handy list of Frequently Asked Questions is detailed in our Switch Independent NIC Partitioning document.

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