45

Virtualbox has three start modes:

  • normal (with a window for the VM but window cannot be closed)
  • headless start (no window for the VM, but you can see a screenshot in VBox UI)
  • detachable start (a mix of the above two; window can be closed without turning off VM)

I was wondering, why do they have these three options when the third one satisfies the first and second? Is it possible there are also performance reasons?

In other words, why should I ever need to use the other options?

2
  • IIRC these options are relatively new.
    – Daniel B
    Jan 26, 2016 at 8:52
  • at my host ubuntu16.04 screen of the vm turns black when windows is starting. Probably at the time, windows loads some graphics.
    – Cutton Eye
    Oct 20, 2020 at 8:08

2 Answers 2

37

You can read why in the current version of the user manual for the startvm command:

Starts a VM with detachable UI (technically it is a headless VM with user interface in a separate process). This is an experimental feature as it lacks certain functionality at the moment (e.g. 3D acceleration will not work).

So, yes, this is still a new feature and it is missing some of the features a fully attached GUI provides.

2
  • 1
    Is this answer still up-to-date ? I'm guessing things changed since 2016
    – Magix
    Jun 23, 2020 at 8:45
  • 1
    @Magix A post from September 2020 suggests that 3D acceleration still doesn't work in detached/headless mode. Oct 2, 2020 at 19:00
9

(Not enough reputation to comment here, so apologies for the "new answer" instead)

This isn't an option in the UI, but is an option in the command line tool.

VBoxManage modifyvm "vmname" --defaultfrontend headless

  • Sets the VM named "vmname" to headless start if you just click the big green Start button

VBoxManage modifyvm "vmname" --defaultfrontend separate

  • Sets the VM named "vmname" to detachable start if you just click the big green Start button

VBoxManage modifyvm "vmname" --defaultfrontend gui

  • Resets the VM named "vmname" to the default integrated (non-detachable) GUI start if you just click the big green Start button
3
  • 1
    The options are also available in the VirtualBox Manager UI, in the "Show" (green arrow) dropdown box.
    – Roger Dahl
    Mar 1, 2021 at 18:12
  • 2
    Works! -> to get the list of vms: VBoxManage list vms
    – NicoKowe
    Oct 23, 2021 at 16:05
  • This is useful if you have a group of VMs you want to start, but don't want them all to start in GUI mode. Thanks :) Aug 3 at 21:56

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