VBoxManage, the command line tool of VirtualBox, does its job. It also has its limitations. You can starts, pause, and save virtual machines, but there is no integrated way to automate various processes. To have a virtual machine boot with the host, in headless mode, you would have to create a custom init.d boot script. A great script package, call VBoxTool, coordinates the process into a terminal app. The terminal app refereneces two configuration files in your /etc directory, and utilizes an init script to boot virtual machines. VBoxTool is at sourceforge:

http://vboxtool.sourceforge.net/

Configure the machines you want to boot in:

/etc/vboxtool/machines.conf

Any machine listed in machines.conf will boot with the host. You can view running machines with:

vboxtool showrun

Then you can also view all available machines with:

vboxtool show

Maybe this wrapper script will be integrated into VBoxManage directly; it is clear the features are useful especially for system administrators.