Ubuntu – How to run a 64-bit guest in VirtualBox

cpu-architecturevirtualbox

I would like to have an Ubuntu 11.04 64-bit test environment. When I try booting the Ubuntu 11.04 64-bit installation CD in VirtualBox, the following message is displayed by VirtualBox:

VT-x/AMD-V hardware acceleration has
been enabled, but is not operational.
Your 64-bit guest will fail to detect
a 64-bit CPU and will not be able to
boot.

Please ensure that you have enabled
VT-x/AMD-V properly in the BIOS of
your host computer.

What am I doing wrong?

Details:

  • VBox.log, ubuntu-test.vbox, and /proc/cpuinfo.
  • Kernel: Linux aux 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:24 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
  • The Virtualization setting in the BIOS is set to Enabled.

Best Answer

  • In order to be able to run a 64-Bit system in a VirtualBox, you need a cpu which supports virtualization. AMD calls this function AMD-V, Intel uses VT-x. The Wikipedia explains this quite good. There are a couple of Pentium-4 CPUs which are able to run a 64-Bit OS, but don't offer this VT-x technologie. You can check your system by...

    $ egrep '(vmx|svm)' /proc/cpuinfo
    flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx cid cx16 xtpr lahf_lm
    flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx cid cx16 xtpr lahf_lm
    

    If you don't get any output, you're not able to run a 64-Bit OS as guest inside your VirtualBox. But don't forget to check your BIOS settings. You might be able to activate these AMD-V/VT-x features inside the BIOS of your computer.

    And finally there's a checkbox inside the VirtualBox-Settings. Start VirtualBox, select the virtual machine where you want to run your 64-Bit OS and go into the settings of this VM. Look for "Settings -> System -> Acceleration" and make sure that "Enable VT-x/AMD-V" is activated.