Intel VT (Virtualization Technology) is a set of processor enhancements, which enables virtualization platforms to offload workloads to system hardware, thus run virtual machines at “near native” performance.

Especially when you want to install virtualization software onto another virtualization platform, Intel VT can greatly improve the performance. For example, you may want to install VMware ESX Server 3i onto VMware ESX Server 3 or VMware Workstation 6.

On an ESX Server, to determine whether Intel VT is enabled, you can use the esxcfg-info command. Although you can reboot the machine and go to BIOS setting to confirm it, this command should be the most convenient way.

Logon to the Service Console, and type:

esxcfg-info -w | grep VT

you will get the following output if VT is enabled:

|—-VT Support…………………………………………3

(Values other than 3, such as 0, 2 should mean “no VT available” and “VT disabled” respectively, although I am not very sure)

NOTE: The above flag is only for ESX Server 3.0.x. In ESX Server 3.5.x, it is called “HV Support”, not “VT Support”. Therefore you have to change the command as following in ESX 3.5:

esxcfg-info -w | grep HV