3–Fibre Channel ConfigurationConfiguring Virtual Ports (NPIV)49 BK3254601-00 CThe physical port or WWN always has high priority, independent of the bandwidthor priority scheme chosen for created virtual ports. You need not assign a QoSlevel to every virtual port that you create. If a QoS level is not assigned to a virtualport, the default is low priority (best effort), independent of the bandwidth orpriority scheme. This flexibility allows you to focus on critical applications toensure that the highest service level is provided. You can modify QoS levels forvirtual ports using QConvergeConsole CLI.To modify QoS levels, the configuration must meet the following hardware andsoftware requirements: Server operating system: Microsoft® Windows Server 2008 or later Server support for MSI-X A QLogic 2700 Series Adapter Latest version of the QLogic STOR miniport driver, available fromhttp://support.dell.com Fibre Channel switch that supports NPIV Physical port attached in a point-to-point connectionSetting QoS by BandwidthSetting the QoS by bandwidth allocates up to 80 percent of the physical port’sbandwidth to its virtual ports. The remaining 20 percent is reserved to handlenon-QoS applications and virtual ports.Setting QoS by bandwidth guarantees bandwidth for each virtual port and to theapplication or virtual machine (VM) associated with that virtual port. The properQoS setting can prevent bottlenecks that occur when VMs contend for portbandwidth.Consider how much bandwidth is required to maximize application or VMperformance and set the QoS level to 105 percent of that value. For example, if amission-critical application on a VM requires 1Gb of bandwidth to transmit its dataover the fabric, QLogic recommends a 1.05Gb bandwidth for the virtual port.Alternatively, you can set the virtual port QoS values as a percentage of the totalavailable bandwidth.NOTESetting QoS by bandwidth guarantees a minimum bandwidth to a virtualport, but not a maximum limit. If the application or virtual port requires morebandwidth than the QoS bandwidth value allows and the physical port hasavailable bandwidth, the application receives the additional bandwidth. Theport allocates additional bandwidth on demand up to the port capacity oruntil there is contention for bandwidth among the virtual ports.
