You can create a MSCS cluster that consists of two or more virtual machines on two ESXi or more hosts.

A cluster across physical hosts requires specific hardware and software.

ESXi hosts that have the following:

Two physical network adapters dedicated to the MSCS cluster and to the public and private networks.

One physical network adapter dedicated to the VMkernel.

Fibre Channel (FC) SAN. Shared storage must be on an FC SAN.

RDM in physical compatibility (pass-through) or virtual compatibility (non-pass-through) mode. VMware recommends physical compatibility mode. The cluster cannot use virtual disks for shared storage.

Failover clustering with Windows Server 2008 is not supported with virtual compatibility mode (non-pass-through) RDMs.