Configuring FCoE Adapters
ESXi can use Fibre Channel over Ethernet (FCoE) adapters to access Fibre Channel storage.
The FCoE protocol encapsulates Fibre Channel frames into Ethernet frames. As a result, your host does not need special Fibre Channel links to connect to Fibre Channel storage, but can use 10 Gbit lossless Ethernet to deliver Fibre Channel traffic.
To use FCoE, you need to install FCoE adapters. The adapters that VMware supports generally fall into two categories, hardware FCoE adapters and software FCoE adapters.
Hardware FCoE Adapters. Hardware FCoE adapters include completely offloaded specialized Converged Network Adapters (CNAs) that contain network and Fibre Channel functionalities on the same card. When such an adapter is installed, your host detects and can use both CNA components. In the vSphere Client, the networking component appears as a standard network adapter (vmnic) and the Fibre Channel component as a FCoE adapter (vmhba). You do not have to configure a hardware FCoE adapter to be able to use it.
Software FCoE Adapters. A software FCoE adapter is a software code that performs some of the FCoE processing. The adapter can be used with a number of NICs that support partial FCoE offload. Unlike the hardware FCoE adapter, the software adapter must be activated.