Boot VirtualBox from USB Drive

A Story that Turns into a Use Case

While doing some year-end back up and archiving I had to reconsider my use of TrueCrypt given the announcement this past year. Do I really need TrueCrypt and cross platform support for my cold storage of GPG keys and Bitcoin wallets if I use Linux 90% of the time? Maybe not, maybe I can just use LUKS which is very popular and less suspect these days.

If I’m going to use LUKS, then I want to prove to myself that I can access it from Windows or Mac OS X if I need to. The question was raised: Can I boot from my Bootable GRUB2 Emergency Flash Drive using VirtualBox? And so the use case was born.

Turns out it was semi easy to do.

How To

1. Setup DEV for the device to be accessed from the virtual machine:

   DEV=/dev/sdx
   

2. Create the VirtualBox disk (on Linux, other OS are similar):

   sudo chown $USER $DEV
   VBoxManage internalcommands createrawvmdk -filename ~/VirtualBox\ VMs/usb.vmdk -rawdisk $DEV
   

   Unfortunately the permissions are screwy and your local user needs to access $DEV. Since udev manages /dev these days, the permissions will revert to normal on the next hotplug.

3. Create a new VirtualBox machine. When prompted to create a new hard drive, specify ~/VirtualBox VMs/usb.vmdk. Ubuntu 14.04 Desktop requires at least 1 GB of RAM, so keep that in mind when creating the virtual machine.

Apple OS X Notes

• Sometimes OS X insists on automounting volumes which causes VirtualBox to complain about with errors like VBOX_E_OBJECT_NOT_FOUND. Try unmounting to release the resource:

    diskutil unmountDisk $DEV