Headless VirtualBox in ubuntu server.

1) I tried to get a headless VirtualBox running in the virtualbox which I could apt-get from a standard Ubuntu Hardy repository. - turns out that that version of virtual box does not support headless mode.

2) Then I tried to install a version of virtualbox I downloaded previously from sun (virtualbox_1.6.2-31466_Ubuntu_hardy_i386.deb) but it failed to compile its kernel module, even after I installed the kernel source:

# /etc/init.d/vboxdrv setup
* Stopping VirtualBox kernel module
* done.
* Removing old VirtualBox kernel module
* done.
* Recompiling VirtualBox kernel module
* Look at /var/log/vbox-install.log to find out what went wrong

3) Then I downloaded the latest version from sun, installed it:

# gdebi virtualbox_1.6.4-33808_Ubuntu_hardy_i386.deb

and it worked beautifully!