Only detected a i686

One of the servers I manage is currently running Ubuntu 12.04 (Precise Pangolin) but in a little over a month 14.04 (Trusty Tahr) will be making an appearance. Now there’s no good reason for me to be rushing out an upgrading but it’s got to be done at some point so I thought I’d get my hands on a nightly build of 14.04 to see what’s changed.

Only a total idiot would run a nightly build of an operating system on a machine they cared about and as I have no spare physical boxes to abuse I’m spinning up a new virtual machine. I quite like VirtualBox as my desktop virtualization product of choice. It’s not quite as slick as the VMware offering but it does give you more control. Normally I have no problems firing up a new virtual machine, just pop in the virtual cd and away you go but today I obviously wasn’t concentrating and ended up with this error message:

this kernel requires an x86-64 CPU, but only detects an i686 CPU, unable to boot

If you google this you’ll find a stack of pages telling you that it’s because you don’t have VT-x or AMD-V enabled in the BIOS of the host. The problem is I know that I do for two reasons: firstly there are no settings for turning them off in my BIOS and secondly I have other 64bit kernels running quite happily.

It turns out that my error was right back when I started setting up the VM. It defaulted to Type: Linux and Version Ununtu. Seeing that I just assumed everything would be fine and hit next. It turns out you have to choose Ubuntu (64 bit) as the version. If you don’t want to trash your VM you can change this under Settings > General > Basic > Version. It would be nice if VirtualBox could somehow warn about this issue. I can’t see why it couldn’t provide a 64bit processor to 32bit OSes unless the user specifically tells it to use a 32bit CPU.

Anyway, it’s fixed now so on with the show…

Posted in Linux, Virtualization and tagged , , , .

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