How can I tell whether or not I have 64 bit or 32 bit VB

[acomber]

Hi

I have installed VB from download page and I just clicked on the VirtualBox 4.1.8 for Windows hosts x86/amd64 link. My host OS is Windows 7 64 bit. Will VB have auto-detected my host OS 'bitness'?

I assume that you can run a 32 or 64 bit guest on a 64 bit VB host? Or not? Presumably it is impossible to run a 64 bit host on a 32 bit VB host?

Reason for question is that I now want to install a RedHat 64 bit guest. Want to know if will be possible for my VB host.

I tried to install a 64 bit linux (RH5.5) but I get the message:

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

Is this something I should see in my BIOS? What is it called?

My PC is a Dell Precision 390. The only relevant setting I could find in the BIOS was a section: Enable virtualisation technology - it is currently off. Is this the option I need to turn on?

Angus

[Perryg]

yes

[acomber]

yes

Not sure what question you are saying yes to... Turning the feature on did the trick. I should have tried it.

I am interested in why there needs to be hardware support for this? anyone know of any links that describe the technology (without the spin)?

[Perryg]

VirtualBox requires VT-x/AMD-v to be able to run 64 bit guests.

You can see the requirements in your VirtualBox users manual.

Start with chapter 1.3 Features overview.

Google also has a lot of information available concerning hypervisors in general.