Setting up a Headless Virtual Machine on a Linux Server Using VirtualBox

1. Install Virtual box

   # For debian
   $ sudo apt-get install virtualbox-ose
   
   # For redhat
   $ sudo yum install VirtualBox-OSE

   Otherwise you can download the source and compile it from http://www.virtualbox.org/
2. Create a Virtual Machine, I will make a Windows XP virtual machine:

# Register the vm's name
VBoxManage createvm --name "Windows XP" --register

# setup the memory/acpi and boot device for the VM
VBoxManage modifyvm "Windows XP" --memory 512 --acpi on --boot1 dvd

# This command will make a brided NIC to the real network eth0
# you can then dedicated IP address for the VM
VBoxManage modifyvm "Windows XP" --nic1 bridged --bridgeadapter1 eth0

# OR This will make a NATed NIC, to which you will have to forward ports
VBoxManage modifyvm "Windows XP" --nic1 nat

# give the vm a hard disk
VBoxManage storagectl "Windows XP" --name="IDE Controller" --add ide
VBoxManage createvdi --filename "WindowsXP-disk01.vdi" --size 10000 --register

# and a dvd drive containg the install media
VBoxManage modifyvm "Windows XP" --hda "WindowsXP-disk01.vdi"
VBoxManage modifyvm "Windows XP" --dvd /path/to/windows_cd.iso

# display some info about he vm
VBoxManage showvminfo "Windows XP" --details
				

3. Now start your VM

   VBoxHeadless --startvm "Windows XP" --vnc --vncport 12345 --vncpass password

   You can now connect to it using VNCViewer