When you set up ESXi hosts to use FC SAN storage arrays, special considerations are necessary. This section provides introductory information about how to use ESXi with an FC SAN array. Fibre Channel SAN ConceptsIf you are an ESXi administrator planning to set up hosts to work with SANs, you must have a working knowledge of SAN concepts. You can find information about SANs in print and on the Internet. Because this industry changes constantly, check these resources frequently. Using Zoning with Fibre Channel SANsZoning provides access control in the SAN topology. Zoning defines which HBAs can connect to which targets. When you configure a SAN by using zoning, the devices outside a zone are not visible to the devices inside the zone. How Virtual Machines Access Data on a Fibre Channel SANESXi stores a virtual machine's disk files within a VMFS datastore that resides on a SAN storage device. When virtual machine guest operating systems send SCSI commands to their virtual disks, the SCSI virtualization layer translates these commands to VMFS file operations.