There are several advantages to enabling hardware virtualization technology in the BIOS of your servers when using vSphere or ESX. These include the ability to use EVC (Enhanced vMotion Compatibility) on your DRS clusters, the use of 64bit OS guests, and using VMware FT (Fault Tolerance).
Turning Intel VT or AMD-V on must be done on the BIOS of your ESX host. In order to tell if it is enabled on your host currently (or if your host supports turning it on) you can run the following command in the service console of the host.
#esxcfg-info|grep HV
The command will return a code:
0 – VT/AMD-V indicates that support is not available in this hardware.
1 – VT/AMD-V indicates that VT and AMD-V might be available but they are not supported in this hardware.
2 – VT/AMD-V indicates that VT and AMD-V are available but are currently not enabled.
3 – VT/AMD-V indicates that VT and AMD-V are enabled in the BIOS and can be used.
