Learn more about Vagrant VirtualBox & enable nested Virtualization. Our Server Management Support team is here to help you with your questions and concerns.

Vagrant VirtualBox Enable Nested Virtualization

Working with VirtualBox and Windows Subsystem for Linux 2 has often been a source of frustration.

When we use VirtualBox on Windows with WSL2 enabled, we have to use the hyper-v paravirtualization engine. Unfortunately, this engine doesn’t play well with Vagrant, limiting our options.

However, our experts have a solution! We can leverage nested virtualization in WSL2 to overcome this limitation. By running VirtualBox directly inside WSL2 without any paravirtualization constraints, we can unlock a new level of flexibility. The key is to set up a custom kernel for WSL2 with the right kernel modules. Let’s take a quick look at the process.

Building a Custom Kernel for WSL2

1. To begin with, make sure the following kernel configurations are in place:

   CONFIG_MODULES=y
CONFIG_MODULE_SIG=n
CONFIG_SECURITY_LOADPIN=n
CONFIG_SECURITY_LOCKDOWN_LSM=n
2. Then, manually disable the `config_module_sig` check to make sure the `module_sig_check` function always returns 0. We have to make this change in `kernel/module.c` at line 2786.
3. Now, it is time to build the kernel and install the modules to `/lib/modules`:

   sudo make -j $(nproc)
sudo make -j $(nproc) modules_install

Setting Up VirtualBox in WSL2

After the custom kernel is in place, the process becomes more straightforward:

1. Update `%userprofile%\.wslconfig` to use the new kernel image.
2. Then, install VirtualBox-6.1.

After the above steps, we have successfully sidestepped the paravirtualization limitations.

Vagrant Compatibility

We can make Vagrant work seamlessly with this setup with these additional steps:

1. To begin with, use a Vagrant branch that disables checks for WSL.
2. We can build Vagrant with the following instructions:

   
cd ~
git clone https://github.com/askalice/vagrant
cd vagrant
bundle install
bundle -- binstubs exec
export PATH="$(dirname ~/vagrant/exec)/exec:$PATH"

3. For parallel Vagrant installs against Windows, we have to add the following to our `.bashrc`:

   
export VAGRANT_WSL_NESTED_VIRTUALIZATION=true
export VAGRANT_HOME=~/.vagrant-wsl2
export VAGRANT_DOTFILE_PATH=.vagrant-wsl2


Running Virtual Machines with Nested Virtualization

If you want to run lab environments on a Mac using VirtualBox, follow these steps:

1. Download and install the latest version of VirtualBox for MacOS.
2. Then, install Vagrant.
3. Now, create a `Vagrantfile` in our desired directory with the following contents:

   Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/trusty64"
# enable nested virtualization
config.vm.provider "virtualbox" do |vb|
vb.customize ['modifyvm', :id, '--nested-hw-virt', 'on']
end
end

4. Finally, launch the virtual machine with `vagrant up`.

Let us know in the comments if you run into any trouble with the above instructions.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

In brief, our Support Experts introduced us to Vagrant VirtualBox & enablng nested Virtualization