64 bit - amd64 virtual machine in virtualbox

18
2014-04
  • juanpablo

    I have ubuntu 12.04

    $ lsb_release -rc
    Release:        12.04
    Codename:       precise
    $ uname -a 
    Linux pablo-desktop 3.2.0-20-generic #33-Ubuntu SMP Tue Mar 27 16:42:26 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
    

    I have installed virtualbox 4.2, I try make a virtual machine with debian amd64

    http://cdimage.debian.org/debian-cd/6.0.4/amd64/iso-cd/debian-6.0.4-amd64-netinst.iso
    

    but only work with a debian i386

    http://cdimage.debian.org/debian-cd/6.0.4/i386/iso-cd/debian-6.0.4-i386-netinst.iso
    

    why?

  • Answers
  • Takkat

    From your details I assume you run a 64-bit Ubuntu host, likely Ubuntu 12.04 beta. It is not clear what version of Virtual Box is installed. The at present most recent Virtual Box release is 4.1.14. Depending on your CPU you also may want to enable it's virtualization features in the BIOS (VT-x for Intel, or AMD-V).

    • Both, your host, and Virtual Box should be able to run 32-bit or 64-bit Debian as a guest. However support for Linux Kernel >= 3.2. was only added in Virtual Box version 4.1.8.

    • Let me suggest you try to update both, your host Ubuntu (at present kernel 3.2.0-24), and Virtual Box (see also this answer).

    • The virtual machine from Virtual Box Manager needs to be set to 64-bit in General -> Basic settings:
      enter image description here

    • In addition, for running 64-guests it is recommended to enable the Input/Output in the System -> Motherboard settings for your virtual machine:
      enter image description here

    • In the System -> Acceleration tab we may want to select the hardware virtualization features VT-x/AMD-V of your CPU if supported.


  • Related Question

    64 bit - Run 64bit OS in Virtual Box from 32bit Ubuntu
  • johnc

    Is it possible to run Windows 7 64 bit from a 32bit ubuntu OS?

    I can reinstall Ubuntu as a 64bit OS, but would prefer not to if it is not necessary.


  • Related Answers
  • luri

    From VB help:

    VirtualBox supports 64-bit guest operating systems, even on 32-bit host operating systems, provided that the following conditions are met:

    1.-You need a 64-bit processor with hardware virtualization support (see Section 10.3, “Hardware vs. software virtualization”).

    2.-You must enable hardware virtualization for the particular VM for which you want 64-bit support; software virtualization is not supported for 64-bit VMs.

    3.-If you want to use 64-bit guest support on a 32-bit host operating system, you must also select a 64-bit operating system for the particular VM. Since supporting 64 bits on 32-bit hosts incurs additional overhead, VirtualBox only enables this support upon explicit request.

    On 64-bit hosts (which typically come with hardware virtualization support), 64-bit guest operating systems are always supported regardless of settings, so you can simply install a 64-bit operating system in the guest.

  • j-g-faustus

    For Virtual Box, here's the Virtual Box FAQ:

    Note that VirtualBox also supports 64-bit guest operating systems, under the following conditions:

    • You need a 64-bit processor with hardware virtualization support (VT-x or AMD-V)
    • Since version 2.1.0, you can run 64 bit Guests while running a 32 bit Host.
    • You must enable hardware virtualization through your BIOS

    So it depends on your CPU. Just having a 64-bit processor isn't sufficient, the CPU also needs hardware virtualization support.

    As an example, the Intel i3 540 is listed as having "Intel® Virtualization Technology (VT-x): yes", so it should work there.

  • RolandiXor

    If your BIOS and processor support it, then yes. I'd suggest using hardinfo to check your processor's features. However you are better off using the 64bit OS as host anyway.

    Even if you processor supports VTx your BIOS may not (many HP laptops for example do not allow you to turn this on), so you have to know if your BIOS also supports it.

  • William Schaub

    I found that on my Ubuntu Lucid (32bit install) machine that it will complain that hardware virtualization is not turned on when it really is. The reason it does this is because the kvm module is loaded. I blacklisted kvm and kvm_amd and now Virtualbox loads up 64 bit guests on a 32bit host just fine.