
Determining use cases for Fiber Channel zoning
In a Fiber Channel (FC) fabric, zoning provides the access rules to define who can talk with whom: which initiator can talk with which target.
A typical full switched FC fabric is like this one:

You need to configure both switch 1 and 2 with the correct zoning, with rules based on the switch port or, better, on the World Wide Name (WWN) addresses (similar to the physical address of a NIC).
Each zone defines which HBA port can connect to which Storage Processors (SP) port or ports.
A proper zoning has the following advantages:
- Reduces the number of targets and LUNs presented to a host
- Controls and isolates paths in a fabric
- Can prevent non-ESXi systems from accessing a particular storage system, and from possibly destroying VMFS data
- Can be used to separate different environments
Note that, at storage level, there is also the LUN masking option to show or hide specific LUNs from a specific host.
For more information, see the vSphere 6.5 Storage guide (https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.storage.doc/GUID-E7818A5D-6BD7-4F51-B4BA-EFBF2D3A8357.html).