For vSphere 5.5 and earlier, a SAN is required to connect the storage system to the VMware ESX Server host as VMware does not support FC-AL and direct-connect connections to storage systems.
For vSphere 6.x, direct-connect connection to the storage system is supported with 8G FC using FC-AL or with 16G FC using point-to-point. For information about setting up storage arrays for VMware ESX Server, see the VMware user documentation.
For details about supported switches, topology, and firmware versions for SAN configurations, see the Hitachi Product Compatibility Guide: https://compatibility.hitachivantara.com