ESXi 5.5 supports FCoE storage and up to 5 node MSCS clusters using Cisco FNIC and Emulex FCoE adapters.
ESXi 5.5 supports FCoE for Windows Server 2008 SP2, Windows Server R2 SP1 and Windows 2012 server GOS only. Windows Server 2003 is not supported.
Cluster-across-box (CAB) and cluster-in-a-box (CIB) are supported. A mixture of CAB and CIB is not supported.
CAB configurations are supported with some cluster nodes on physical hosts. In a CAB configuration, a max of one virtual machine in a host can see a LUN.
In a CIB configuration all virtual machines must be on the same host.
No qualification is needed for SWiSCSI and FCoE initiators in a guest operating system.
N+1 cluster configuration, in which one ESXi host has virtual machines which are secondary nodes and one primary node is a physical box are supported.
Standard affinity and anti-affinity rules apply for MSCS virtual machines.
All hosts must be running ESXi 5.5.
All hosts must be running FCoE initiators. Mixed cluster nodes running FC and FCoE are not supported.
Mixed mode FCoE configuration is supported. For example, Node A on ESXi with an FCoE software adapter intel based card and Node B on ESXi with an Emulex or Cisco FCoE hardware adapter.
Mixed mode configurations of ESXi 5.5 with previous ESXi releases are not supported.
Rolling upgrades of cluster hosts from previous versions of ESXi to ESXi 5.5 builds are not supported.