OpenNebula Storage Question


I’m new with OpenNebula, and I have read all docs about architecture.

My physical infrastructure is based on a blade center with 3 servers and two fiberchannel SAN connected on the blade.
My idea was to use these 3 servers as KVM Hosts and store VM disk in the SAN ( 4 differents LUN as shared primary storage if I’m right).
If I have understand the frontend configuration, the front-end server must have access to the storage, so must have access to the SAN by the fiberchannel network, so must be physical. Right ?
So front-end could not be virtual and I must to create a physical cluster to this server to have a failover architecture ?

Thanks for your help,