A: Considering upgrading your availability on a VMware virtual machine? Need more availability than VMware high availability alone can handle? In the VMware portfolio of features, fault tolerance is your next step.

Enabling fault tolerance, however, automatically places some restrictive demands on VM configurations. As a result, many VMs simply cannot be configured for fault tolerance. Consider these VM requirements for fault tolerance in vSphere 5.0 before enabling this feature:

  • Unsupported devices and incompatible features can't be associated with the VM.
  • VMs must be stored in virtual RDM or virtual machine disk (VMDK) files that are thick provisioned.
  • VM files must be stored on shared storage.
  • VMs must be configured with only a single vCPU.
  • VMs must be running on one of the supported guest OSs. Those supported OSs can be found in the VMware Knowledge Base article "Processors and guest operating systems that support VMware Fault Tolerance."