Virtual machine fails to power on with error: Longmode is unsupported. It is required for 64-bit guest OS support. On Intel systems, longmode requires VT-x to be enabled in the BIOS

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• When attempting to power on a virtual machine with a 64-bit operating system, you encounter the following error:

Longmode is unsupported. It is required for 64-bit guest OS support. On Intel systems, longmode requires VT-x to be enabled in the BIOS. On nested virtual ESX hosts, longmode requires the "Virtualized Hardware Virtualization" flag to be enabled on the outer VM.

• You may experience errors similar to:

msg.cpuid.noLongmodeQuestionFmt: The host is VT-capable, but VT is disabled. Enable VT and disable trusted execution

This kernel requires an X86-64 CPU, but only detected an i686 CPU. Unable to boot – please use a kernel appropriate for your CPU

Environment

VMware vSphere ESXi 5.1

Cause

This issue occurs when Virtualization Technology (VT) is not enabled on the host.

Resolution

To resolve this issue, enable Virtualization Technology (VT) within the host BIOS.

For more information on enabling this feature, consult your hardware vendor documentation.

Additional Information

次のエラーで仮想マシンのパワーオンができない：Longmode is unsupported. It is required for 64-bit guest OS support. On Intel systems, longmode requires VT-x to be enabled in the BIOS
虚拟机打开电源失败并显示错误：不支持长模式。64 位客户机操作系统支持需要使用此模式。在 Intel 系统中，长模式需要在 BIOS 中启用 VT-x