Virtual Box Guest on Windows 10 guest in Proxmox reports no VT-x.

[JC Connell]

Hello,

I have a Proxmox host that I use for a lot of testing and fun things. A MacBook is my primary machine, and since I sometimes need a Windows OS, I keep one installed on the PVE host for the rare times it's needed.

I'm working on an assignment that has required me to download a Virtualbox template to complete. I installed Virtualbox on the Windows 10 guest, then installed the template. The first time I ran the VB guest, it started fine but was exceptionally slow. I shut down the Windows 10 guest, added more RAM and started everything back up. Now the Virtualbox Guest reports that my CPU does not support VT-x when I try to start it.

I enabled nested virtualization thinking it may solve the problem, but it hasn't. My host has 2x E5-2670s. Any idea why this isn't working? I realize I can also run Virtualbox on my Macbook but I'd like to fix it on the PVE host if it's possible.

 

[dcsapak]

did you set 'host' as cpu type on the windows guest? (VM->Hardware->Processor->Type)

 

[wolfgang]

you can also set
args: -enable-kvm
in your config to force nested virtualization

 

[JC Connell]

Thank you, although I read about set host as the CPU type, I must have forgotten to do it after enabling nested virtualization.

With the CPU type set as 'host', I can now launch the Virtualbox Guest without the VT-x error, but it crashes the Windows 10 guest seconds after. What should I look into next?

 

[LnxBil]

You can simple convert your VirtualBox OVA file to use it via Proxmox:

* create an empty VM with a QCOW2 disk (for easy setup)
* untar the OVA-file, this yields at least one VMDK and a config file
* inspect the config file and set parameters of <id>.conf in /etc/pve/qemu-server according to the settings in the config for your VM (disk type SATA/IDE, SMBIOS-Setting, etc.)
* delete qcow2 file and use full path to convert vmdk to qcow2 with qemu-img convert <vmdk> -O qcow2 /full/path/to/file.qcow2
* Snapshot the VM
* Startup.
* Change config if needed and reset to snapshot

 

[manu]

Note that for running a 64bit guest, VirtualBox *will* require the vmx extensions to be present.
However VirtualBox is not able to work with the VMX extension passed by KVM ( the problem comes from the VirtualBox side, see this bug report https://www.virtualbox.org/ticket/4032 )