This event records a fault tolerance failover.
The reason could be: lost connection to primary, partial hardware failure of primary or by user.
Check connectivity to the primary VM, any hardware failure or vCenter event log for user-initiated actions.
The failover should mean that the application/workload running inside the VM is still available; however you should establish the reason for the failover.
See the vSphere Availability Guide for more information.
Refer to the VMware Online Documentation for more information.