Screen won't resize, MacOS Host & Guest

[BillJ]

I'm running an older Mac using its max OS High Sierra, which is why I'm not using VBox 7.

I need to run a VM to run MacOS El Capitan since that's the last version of Safari that has a browser that supports the plugin for my business security camera.

I've installed El Capitan into a virtual box, fire it up and it runs. I can view the security system with Safari.

However, I wanted to add a second screen to my Mac and put the Virtual Box full-screen on that second display. But the VBOX display won't resize from the default 1024x768.

• I have installed the Guest Additions
  I have set the display to VBoxVGA and clicked 3D acceleration
  I have set the display memory to 128 as suggested in another thread

Still doesn't work. When I resize the display I get a "white" box around the outside of the El Capitan virtual machine


Host: MacOS High Sierra 10.13.6, 2011 27" iMac 12,2
Virtual Box 6.1.42 with guest additions installed
Guest: MacOS El Capitan 10.11.6

As requested in prior threads with this issue:

El Capitan.vbox.zip

configuration file

(1.57 KiB) Downloaded 15 times

El Capitan-2023-09-18-14-46-00.log.zip

log file from a clean boot

(36.55 KiB) Downloaded 21 times

[mpack]

I would give the guest OS a second CPU core, otherwise you'll get very old fashioned lagging whenever the OS is busy.

As to screen resize, GAs for MacOS are almost non-existent (you will notice no mention of them in the user manual). In particular there are no special display drivers: you can disable 3D acceleration btw since it can't do anything. You'll be limited to basic VESA SVGA display modes. Since VirtualBox is not involved any difficulty changing mode must be between you and the guest OS.

[BillJ]

Interesting, I don't seem to have a whole lot of issues with lag, although the only thing that the guest OS is doing is running Safari and displaying the video from my security camera. But I'll toss a 2nd CPU at it if you think I should.

I have a similar setup on my system at home but I'm using Parallels Desktop since I had that for something else that had to run windows before I found out about VBox. High Sierra host, same iMac (12,2), and running El Capitan as a guest and its screen resizes without issue. (with the parallels guest additions or whatever they call it installed of course)


Turned off 3D and changed the display setting to VBOXSVGA and no change, still can't resize the screen.


FWIW the display settings on the El Capitan guest only allow me to choose 1024x768 as the screen size, that's the only one listed even if I check the scale button.


BTW, if someone knows of a newer browser that will run on High Sierra that allows flash plugins I could avoid this issue altogether. I've not been able to find one. And the security camera company says that this system is no longer supported so they're not doing anything to update their software to run on non-flash enabled browsers and it's a royal pain in the ass to replace the entire system just so I can watch what is going on from my office.

[mpack]

Turned off 3D and changed the display setting to VBOXSVGA and no change, still can't resize the screen.

As I said, no display drivers are provided for MacOS, so naturally the graphics chipset choice makes no difference. The only display drivers available to you are the stock VESA SVGA drivers native to MacOS - these are not provided by VirtualBox.

Parallels is payware and focused on MacOS. VirtualBox is neither, so can't be expected to provide a comparable experience.

I suspect that 1024x768 is the largest 4:3 aspect ratio window that fits on your screen. I don't use MacOS hosts or guests, but on Windows hosts with Windows or Linux guests I can drag the window border to change the aspect ratio. Thus convincing the guest that you have a widescreen monitor. This works quite well, e.g. with Win98 guests which are also forced to use VESA SVGA graphics.

[fth0]

Please have a look at Video Modes in EFI.

[BillJ]

"Parallels is payware and focused on MacOS. VirtualBox is neither, so can't be expected to provide a comparable experience."

I understand that, however the point was that El Capitan has no issue with resizing screens when that other VM tells it to do so. It does, however, behave this way if you don't install the parallels "tools" (the equivalent to the guest additions) so I'm wondering if something went wrong with the guest additions install? how can you even tell?


"I suspect that 1024x768 is the largest 4:3 aspect ratio window that fits on your screen. "

I have this issue if I move the window to the main screen, which on a 27" iMac is plenty big and has lots of resolution to go around (2560x1440)

[BillJ]

Using the vboxmanage allowed me to set the resolution higher so it's kind of solved my issue but it still won't allow me to resize the window. But for now, I'm good Thanks for that.

[BillJ]

FWIW I recently upgraded this machine to MacOS X Monterey (12.7) and then was able to upgrade to Box 7. This was not an "upgrade" of the existing system but a complete wipe and re-install from the OS up.

The screen still will not resize

[mpack]

I hate to repeat myself, but...

no display drivers are provided for MacOS

If that situation was different for VirtualBox v7 then I would have said so.