virtualbox.org

Hi Guys,

One of my users is having a critical error on a windows host with a Cent OS 6.1 guest.
Can anyone give me any direction?

Thanks,
Andrew

VBox.log wrote: 00:00:13.786752 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
00:00:13.786754 !!
00:00:13.786754 !! Guru Meditation -4011 (VERR_VMX_IN_VMX_ROOT_MODE)
00:00:13.786778 !!

I think this one means that something else is already using VT-x. Check for another VM platform running (e.g. XP mode), or Hyper-v, or some kind of debugger.

Hi mpack,

Thanks for the response - but I do not think there is anything else running on the machine. It's running Windows 7, so Hyper V is out. XP mode isn't installed on this particular laptop.

This is also still present after a reboot of the host system.

Thanks,
Andrew

Well, I don't know what else I can tell you. The error message says that something else is already using VT-x on this CPU.

VT-x is required to run any VM which has VT-x selected in the options, and all 64bit VMs.

If the problem is still present after a host reboot then the offender must be getting loaded at boot time.

IMHO it's also worth confirming that VT-x has been enabled in the host PC BIOS, though the error message seems wrong for that.

Incidentally, another potential concern I see is that you have a quad core CPU but are assigning 6 cores to the guest. This may result in poor performance, but I don't see it causing this error.

Hi mpack,

Thank you. I will look into it more closely next week when I get a chance.

I've asked the user to reinstall Virtualbox, she said it uninstalled fine, she rebooted, but now it won't reinstall - clearly there's deeper issues with her machine

Cheers,
Andrew

Incidentally, another thing you can try is reducing the guest's RAM allocation from 4GB to 2GB. And btw, you have not explicitly said what the guest is, e.g. is it the 32bit or 64bit variant of CentOS? I assumed 64bit given the other hints (4GB RAM, VT-x enabled).

Thank you for all your help. I fiddled with the settings, reduced it to 4 cores and 2GB of RAM, this seems to have fixed the issue. It's a 64-bit version of CentOS.

Cheers,
Andrew

IMHO, you shouldn't assign more than 2 cores to the VM. You need to leave capacity for the host, and in any case many people find that the VM actually gets slower if you allocate more cores than it needs.

Thanks for the advice - I will pass that on to the user.