A method and apparatus for interfacing a host computer with a hard drive cartridge is disclosed in one embodiment. The virtual device interface is divided between a kernel component in a driver stack of the kernel space and a user component configured to run in user space. The kernel component passes data commands from the operating system to a cartridge dock while separating other commands that are passed to the user component. The user component authenticates the kernel component and/or the hard drive cartridge. Use of the removable hard drive cartridge is also authorized by the user component.