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VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 26. Jul 2016, 17:16
by HF
I have a Windows 10 host with a high DPI screen, 3840 x 2160, and when I run VirtualBox on it some things scale and others don't.

For instance, the font in the guest are correct, but the mouse is too small almost to see.

The fonts in the VBox management console are too large and overlap. Also the menu hosting the guest window is sometimes too small, and other times too large and overlapping itself.

This sounds like a small issue, but it happens to other fonts, controls within VBox as well to the point of not being usable. For the moment, I'm going back to a much older laptop so I can see what I'm working with, but I'd much rather run virtualbox on the new system.

This gets much worse when working with multiple monitors if they do not have the same resolutions. However, I haven't found any other application with these issues.

Thanks

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 26. Jul 2016, 17:35
by HF
Also, if I add a secondary monitor with a lower resolution, the Virtualbox guest is scaled too large to use. I have automatic resolution set and the guest is set to 100% display scaling, just like I've always used before.

This is all with VirtualBox version 5.1.2 and its guest additions. The host is Windows 10 and the guests are Centos 7, Ubuntu, and Windows 7 - all the guests have the same issues.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 27. Jul 2016, 16:01
by kchan
HF wrote:For instance, the font in the guest are correct, but the mouse is too small almost to see.

I run a Linux guest on a high DPI display (220 DPI) too. If you mean the mouse cursor in X, you can set the Xcursor size in $HOME/.Xresources like this:
Code: Select all   Expand viewCollapse view
Xcursor.size: 64


HF wrote:The fonts in the VBox management console are too large and overlap. Also the menu hosting the guest window is sometimes too small, and other times too large and overlapping itself.

I think it has to do with the Windows host itself. On the desktop right click -> Display settings -> drag the slide bar that says "Change the size of text, apps, and other items" to 200% or all the way to the right. You may have to resize the individual windows (VBox Manager, etc) after that though.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 1. Aug 2016, 10:51
by ColinH
I use Windows 10 host and Windows 10 guest. I have a high DPI 5K main screen and standard DPI WQHD second screen. Previously VirtualBox handled this by 2x scaling the main screen and 1x scaling the second screen. Now with latest version 5.1 onwards, that doesn't work. It seems now the scaling is applied equally to both devices. Since the VirtualBox can't create a 5K main screen, I end up with a tiny window in the middle of my screen + second monitor OK, or I get the main screen 2x scaled but the second monitor also 2x scaled which makes it useless.

I think VirtualBox need to handle different scaling on different monitors. My guess is the older version only scaled the main display, which is a reasonable compromise as most people can only afford one high DPI display. Alternatively, improve the graphics card / memory on Virtual Box so I can have a guest with a 5K main screen + WQHD second screen, and then I'll use the guest OS to scale the monitors.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 15. Aug 2016, 23:41
by DwayneB
I see the same issue. I have the following setup:

- Main screen is a Microsoft Surface Book - 3000x2000 resolution - In Settings > Display, window scaling (i.e the "Change the size of text, apps, and other items" setting) is set to "200% (recommended)" for this display.

- Secondary screen is HD resolution 1920x1080 - In Settings > Display, scaling is set to "100% (recommended)" for this display.

Initially starting VirtualBox on the main display, it appears normal like other windows...but when moving VirtualBox windows between my displays (and this is ANY VirtualBox window including the VirtualBox Manager window), it is not obeying the scaling settings that are present for the particular display that the window is now located in. On the HD display, it is still scaled to 200% like the main display which is HUGE and really unusable.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 9. Jun 2017, 10:51
by maeni
The solution, which worked best for me (Win10):
Using the analogous approach for VirtualBox as described at http://www.danantonielli.com/adobe-app- ... plays-fix/ (I cannot post full URLs in this forum yet, so please adapt correspondingly) for adapting application scaling.
When doing this you can leave scaling on guest to 100%. However, the mouse pointer is still too tiny. This can be adapted easily by selecting different schema for mouse in corresponding settings (change to "extra large").

With this solution the VMs scale correctly also when e.g. moving to another external screen with lower DPI.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 9. Jun 2017, 11:53
by socratis
So, did you create a "manifest" for VirtualBox? If so, could you share it?

PS. I fixed that URL for you...

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 9. Jun 2017, 13:23
by maeni
Hi. No problem! Please see attached ZIP with manifest file.
Manifest file must be copied into application folder of VirtualBox (e.g. C:\Program Files\Oracle\VirtualBox).

For completeness, here the important bits from other article (Adobe App Scaling on High DPI Displays):
  1. Press Windows Button + R, type “regedit”, and then click OK.
  2. Navigate to the following registry subkey:
    HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows > CurrentVersion > SideBySide
  3. Right-click, select NEW > DWORD (32 bit) Value
  4. Type PreferExternalManifest, and then press ENTER.
  5. Right-click PreferExternalManifest, and then click Modify.
  6. Enter Value Data 1 and select Decimal.
  7. Click OK. Exit Registry Editor.

Cheers,
Roger

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 9. Jun 2017, 13:47
by socratis
Actually, I've noticed that all 4 of the "manifest" in the 3rd party site (plus yours) are all identical, except the names of the manifest. So it seems that this is a generic guidance towards Windows, a per-application "fix", if the "<Application>.manifest" file exists along the "<Application>.exe". Interesting...

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 9. Jun 2017, 14:52
by maeni
Yes, this fix should work for most Windows applications, for which there are such scaling issues.
By looking into the file, I had recognized that there is nothing application specific, and just gave it a try with VirtualBox.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 14. Aug 2019, 02:25
by KONNEX
wow thanks. this really helps.

VirtualBox looks fine... but VirtualBoxVM looked like s****.
With registry edit and the manifest, it's fixed.

Re: VirtualBox on a high DPI display scales incorrectly (Windows 10 host, any guest)

PostPosted: 6. Sep 2019, 18:36
by Alison
"FWIW"/in case it's useful for anyone who lands here!...

I was running VirtualBox 5.x for aaaaages on my Windows 7 host machine, no troubles. When I got a new work computer with Windows 10, I installed VirtualBox 6.x, because, just because??

So, I had VirtualBox 6.x running on a Windows 10 host, and for the life of me, I couldn't get scaling to work properly (switching from being docked to a full monitor, to my laptop screen, back to being docked to a full monitor) -- everything was teeny tiny, *INCLUDING* the "VirtualBox Manager" window and the "mini toolbar" within my VM (guest machine is Ubuntu).

I fiddled with settings that I don't really understand (DPI scaling, graphics accelerator, graphics controller, several other buttons/checkboxes/dropdowns in Windows and within VirtualBox) for a couple of weeks...

Today, I gave up and went back to VirtualBox 5.2.32. Everything is peachy :) (Although I had to reinstall 6.x for a few minutes to unset the "graphics controller" setting I happened to have selected the last time I fiddled with things while running 6.x.) I'm sad, because, whatever, not using the latest-and-greatest is a bummer! But at this point *shrug* it is what it is, I'll try again someday -- 5.2 will be supported til July 2020. (I'm comforted by the knowledge that it only took a few minutes to install each version, including downgrading/upgrading extension packs, so I really can try again "whenever.")