ESXi Server comes with several native PSA (Pluggable Storage Architecture) to perform certain storage related tasks.
I will go though LUN Masking at ESXi server in this blog. Usually LUN Masking is configured at SAN device to hide LUNs from hosts (HBAs) but ESXi allows you to hide LUNs to be displayed although LUN(s) are not masked by SAN device.
vCenter Server applies storage filters to prevent undesirable LUNs to be displayed during the storage operation. For example if a LUN is used for RDM, a LUN will not be displayed in the list of available LUNs when you try creating a new VMFS Datastore. I cannot find or think about any use case of disabling these features but it can be tested in VCAP exam.
