When a device enters a Permanent Device Loss (PDL) or an All Paths Down (APD) state, vSphere High Availability (HA) can detect connectivity problems and provide automated recovery for affected virtual machines.
vSphere HA uses VM Component Protection (VMCP) to protect virtual machines running on a host in a vSphere HA cluster against accessibility failures. For more information about VMCP and how to configure responses for datastores and virtual machines when an APD or PDL condition occurs, see the vSphere Availability documentation.