This procedure was tested using:
These instructions below assume VirtualBox is managed via its GUI except where commands are given.
blkid
command.VBoxManage internalcommands createrawvmdk -filename ~/VirtualBox/sdc.vmdk -rawdisk /dev/sdc
TODO: does VirtualBox work with a symlink to the USB block device's device file? If so, how about setting up a udev rule to create such a symlink so it does not matter if the USB block device is assigned sdc, sdd, sde ... .