Newest version of Virtualbox is v4.3.6 while running a headless VM as remote server instance can lead to lower resources consumption and faster response on the host computer.
Before starting a headless VM, you need to make sure the VM has Remote Display setup properly. Once a headless VM starts running, the easy way to access the VM would be using RDP viewer. This is particularly useful when you run a headless Windows VM.
To run a VM in headless mode, we can issue the following command:
$ $ vboxheadless --startvm "WHATEVER NAME IT IS FOR VM"
In case of using Virtualbox GUI, you can hold SHIFT key while clicking on START button for the target VM.
If you run into a famous error like NS_ERROR_CALL_FAILED: segmentation fault 11, you should take a look at the setting of the VM whereas 3D acceleration under Video tab should be turned off. You probably don't need 3D acceleration on a headless server VM so it doesn't cause much performance impact at all.
