George Crump is founder of Storage Switzerland, an analyst firm focused on the virtualization and storage marketplaces. Neterion already is doing this, and I expect Fibre Channel over Ethernet companies like Emulex to follow suit soon. In a virtual environment you can have multiple virtual servers all accessing the same I/O path. In the old days of one server and one application, there was little need for QoS, but with multiple virtual machines demanding bandwidth, it quickly becomes a requirement. This assures them the needed bandwidth while not interfering with other workloads on the host.”]
Source: https://www.darkreading.com/database-security/nic-qos-