Enabling and disabling Fault Tolerance on a virtual machine

In addition to VMware High Availability (HA) clustering, VMware also provides the ability to enable Fault Tolerance (FT) to protect a running virtual machine. FT creates a secondary virtual machine on a second host in the cluster and executes all of the same instructions on both the VMs. In the event of a host failure on the server hosting the primary VM, the secondary VM will assume the role of the primary with no downtime. There are no breaks in the network connectivity or application uptime.

In vSphere 5.5, FT has a significant list of requirements, including at least two ESXi hosts with FT compatible processors, shared datastores, and networking hosting the VM. In addition, your ESXi hosts must have a logging network connection between the hosts for Fault Tolerance where the process instructions are transmitted for execution on the secondary VM. Most restrictive, however, is vSphere 5.5 which only supports FT on a virtual machine...