VB 6.00: Display in VM guests very high resolution

[macandroid]

Using a Macbook Pro 2018 13" I used VB 5.2 without problems, but after upgrade to 6.0, the display within the VM appears to be very small: i.e. very high resolution packed on my 13" screen.
The video hardware is the same (1280x800 'retina' screen), but it appears that VirtualBox blows it up to double that size and compresses it in the screen too small for this resolution with text stoo small to be read. Changing global screen scaling does not work anyway, only within each VM individually.
But why does VB since 6.0 'blow up' my resolution to a fake 2560x1600 ?

[socratis]

But why does VB since 6.0 'blow up' my resolution to a fake 2560x1600 ?

VirtualBox does no such thing. Can't. It's you that wanted/got the Retina MacBook. The resolution is exactly what it says it is. Check your MBP specs...

The video hardware is the same (1280x800 'retina' screen)

No, that's OSX doing a 1/4th of your Retina display, your actual display is double that, both horizontally and vertically: (2560x1600)/2=(1280x800). In order for your VMs to "seem" right in terms of scaling, you got to use the Scaling factor. Either per-VM (avoid it!!!) or the Global one. VirtualBox Preferences > Display > Scale Factor: 200%.

If you set the per-VM factor, there's no way to "unset" it and follow the global one, unless you manually edit the ".vbox" file and remove the scaling factor entry (not suggested!!!) or use the following command:

• 
  VBoxManage setextradata <uuid|vmname> "GUI/ScaleFactor"

I've created a new enhancement request to address this shortcoming, ticket #18303: No way in the GUI to reset the per-VM scale factor to follow the global one.

[macandroid]

Thanks for issuing a ticket on this. There was somebody else opening a topic on this.

[socratis]

Thanks @macandroid for reminding me about the other thread, I've added a comment to let the OP know about the ticket. If you want, you can subscribe to the ticket (by adding a simple comment) as well, if you want to see its progress.

[macandroid]

VirtualBox 6.04 still has this problem.
And setting the global setting to 200% does not help, I have to adjust it per VM (which I don't prefer).
Why cannot the way VB handles with Retina displays be set in the same way as earlier versions ? In VB 5.x it worked flawlessly.

[socratis]

And setting the global setting to 200% does not help, I have to adjust it per VM (which I don't prefer).

Read the thread again please, there's no point repeating what's 3 posts back... If you ever "touch" the per-VM scale factor, you can't untouch it, unless you get involved manually.

In VB 5.x it worked flawlessly.

Go to 5.x then. I know that this is a tongue in cheek answer, but 1) I already told you what's the strategy, 2) I have no problem at all with my VMs, which are running on HiDPI and non HiDPI computers. On multiple monitors. The same exactly VMs...

[Sandeep Khanna]

SOLVED

Using the VirtualBox Manager GUI, select the autoscaled output option:

View -> Virtual Screen 1 -> Scale to 200% (autoscaled output)

Key is to select the autoscaled instead of the unscaled (which seems to use the crazy small retina display resolution)

[socratis]

SOLVED

Not really...

What you did is to change the ScaleFactor for a single VM. Not the global one.