When you boot the ESXi host from SAN using software FCoE, certain requirements and considerations apply.
ESXi 5.1 or later.
The network adapter must have the following capabilities:
Be FCoE capable.
Support ESXi open FCoE stack.
Contain FCoE boot firmware which can export boot information in FBFT format or FBPT format.
You cannot change software FCoE boot configuration from within ESXi.
Coredump is not supported on any software FCoE LUNs, including the boot LUN.
Multipathing is not supported at pre-boot.
Boot LUN cannot be shared with other hosts even on shared storage.