Which vSphere feature cannot be used with virtual machines that are enabled for VMware Fault Tolerance? (Choose two)
RDMs in virtual compatibility mode
Page 41 of vsphere-esxi-vcenter-server-50-availability-guide.pdf
Virtual Machine Requirements for Fault Tolerance
You must meet the following virtual machine requirements before you use Fault Tolerance.
* No unsupported devices attached to the virtual machine. See Fault Tolerance Interoperability, on page 41.
* Virtual machines must be stored in virtual RDM or virtual machine disk (VMDK) files that are thick provisioned. If a virtual machine is stored in a VMDK file that is thin provisioned and an attempt is made to enable Fault Tolerance, a message appears indicating that the VMDK file must be converted. To perform the conversion, you must power off the virtual machine.
* Incompatible features must not be running with the fault tolerant virtual machines. See Fault Tolerance Interoperability, on page 41.
* Virtual machine files must be stored on shared storage. Acceptable shared storage solutions include Fibre Channel, (hardware and software) iSCSI, NFS, and NAS.
* Only virtual machines with a single vCPU are compatible with Fault Tolerance.
* Virtual machines must be running on one of the supported guest operating systems. See the VMware knowledge base article at http://kb.vmware.com/kb/1008027 for more information.
vSphere Features Not Supported with Fault Tolerance
The following vSphere features are not supported for fault tolerant virtual machines.
* Storage vMotion. You cannot invoke Storage vMotion for virtual machines with Fault Tolerance turned on. To migrate the storage, you should temporarily turn off Fault Tolerance, and perform the storage vMotion action. When this is complete, you can turn Fault Tolerance back on.