Last night I was working on getting some screenshots of Kubuntu for the Karmic to Lucid upgrade documentation. I typically use Qemu for all of my virtualization needs because: a) it is convenient, b) it is fast, and c) both a and b. One thing I was noticing last night in Qemu was the default wallpaper for KDE SC 4.4 wasn’t blue, but more of a light and ugly brown color. Not Ubuntu brown, or should I say the old Ubuntu brown. What I found a bit weird with this is when I used KSnapShot to take a screenshot, the preview image in KSnapShot showed the correct color of the wallpaper, however when I opened it in Gwenview on my local machine and not in the Qemu guest, the wallpaper was brown and not blue. This drove me nuts, and it still does, because I can’t find any information on such a case. I know I can’t be the only one experiencing this?
Anyways, with the issues I was having, today I decided to go ahead and throw VirtualBox on my machine for screenshots. After getting it installed, rebooting, and doing what you have to, I went to fire up VirtualBox and was presented with the following error message when trying to start a guest OS:
Failed to start the virtual machine Kubuntu
VirtualBox can’t operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_VMX_IN_VMX_ROOT_MODE).
First off…Really? That is the error you are presenting to the user? VERR_VMX_IN_VMX_ROOT_MODE – oh this really makes me know what the problem is, this should be easy. Did you see what I did there? Yes, I presented you with sarcasm. VirtualBox developers, do me a favor, make your error messages a bit more user friendly. Simply telling the user to “disable extension” and then “recompile kernel” is about as insane of an option for what I consider an awesome end product. FYI people, you don’t need to recompile your kernel, unless of course you compiled your kernel with the KVM module and can’t do anything about it, but I would guess for 99.9% of you, this isn’t the case. And another thing, put that VERR_VMX_IN_VMX_ROOT_MODE garbage under the Details drop down, hide that damn thing.
OK, with that off my chest, easy fix. Fire up your terminal and fire off the following:
Ubuntu or Ubuntu based distro, or distro using Upstart:
sudo stop qemu-kvm
For a non-Ubuntu based distro or distro not using Upstart:
sudo service qemu-kvm stop
And if all else fails:
sudo /etc/init.d/qemu-kvm stop
Now you can fire up VirtualBox and rock-and-roll. If you need to use Qemu again before rebooting or shutting your system down, instead of issuing stop to the examples above, use start instead. This is only a temporary work around. If you reboot your machine after stopping qemu-kvm, when your system starts back up, you will need to stop it again in order to use VirtualBox.