Lost display resolution setting in Guest OS

[Lewish]

If I turn the monitor off, Win 7, which is the Guest OS, loses the display resolution setting. When I turn the monitor back on, I have the original desktop in the background, but it is inactive. The active desktop is now at 640 x 480. Before turning the monitor off, desktop resolution was 1920 x 983. That is not available after turning the monitor on again.

How do I get 1920 x 983 resolution again?

Thanks for any help.


Lewis

[socratis]

In order to better understand the problem you need to submit some more information. Please read the following: Minimum information needed for assistance.

[Lewish]

OK, new user, so I didn't know about that info.

I am running VirtualBox 5.1.22 under 64 bit Debian Jessie. 16 GB of system memory. I have the 5.1.22 Extension Pack installed.

The Guest OS is Win 7 32 bit. I have Guest Additions installed under that. I have allocated 4 GB of memory.

I just booted the Guest and the log file from that is attached.

Any thing else that I can provide to help solve this problem?


Thanks

[socratis]

The only screen size I see your guest getting is the one that you're saying you're missing:

00:00:15.413387 VBVA: InfoScreen: [0] @0,0 1920x983, line 0x1e00, BPP 32, flags 0x1
00:00:15.413395 Display::handleDisplayResize: uScreenId=0 pvVRAM=00007f8240000000 w=1920 h=983 bpp=32 cbLine=0x1E00 flags=0x1
00:00:15.413423 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=1920x983, Sending to async-handler
00:00:15.413450 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=1920x983
00:00:15.413457 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=1920x983

PS. For future reference, you should completely shut down the VM before grabbing the VBox.log. Then ZIP it before attaching it to your response.

[scottgus1]

With Guest Additions, the guest can be set to change screen size settings when the host window size changes ("Auto Resize guest Display"). And the host window size may change when...

I turn the monitor off

Maybe your host OS loses the monitor settings when this happens? Can you remote into the host OS and watch what the host OS does with the screen which is shown by the monitor you turn off?

If it is necessary for your guest to stay at the desired size despite your host monitor changes, you my need to turn off "Auto Resize Guest Display" in the guest's window View menu.

[Lewish]

I am not sure what you mean by this "Maybe your host OS loses the monitor settings when this happens? Can you remote into the host OS and watch what the host OS does with the screen which is shown by the monitor you turn off?"

The host display resolution is 3840 x 2160. That is not affected when I turn the monitor off and back on. It is only the Guest that gets confused.

With "Auto Resize guest Display" enabled, the result is, I still have as background what was being displayed when I turned the monitor off, but now the active area is the same size as when "Auto Resize guest Display" wasn't turned on. Then, if I look at the screen resolution, it thinks it is displaying 1920 x 983. And it seems that is what it is doing because I have to use the scroll bars to see various area of the desktop.

So, needless to say, I am at a loss as to what is going on.

My graphics card is a ASUS GTX 750 Ti GDDR5 2GB. I have spoken with Nvidia, and their response is, it is a VirtualBox driver problem.

So, now what?

Thanks

[scottgus1]

their response is, it is a VirtualBox driver problem

'Twould be the normal response - it's always the other guy's fault.

That it isn't a normal problem is suggested by the fact that the whole forum hasn't blown up over the issue.

The guest OS will change screen size according to what the host window size is, when "Auto Resize guest Display" is turned On. I think you have the setting backwards in your report.

What I meant by "Maybe your host OS loses the monitor settings" is perhaps the Debian host forgets how big the screen size feeding the monitor was when the monitor is turned off. If it resets the screen size to a small screen, then the guest window would get smaller, thus forcing the guest screen size smaller when "Auto Resize guest Display" is turned On. I don't know if this is happening, but it might be.

Your issue likely resides in your Linux host. Maybe the "Linux Hosts" forum might get you some different ideas to check.

[Lewish]

Thanks for the reply.

I suspect one reason this forum hasn't blown up over this issue is, very few people are running 4K monitors and very few graphics cards support 4K resolution.
Also, even fewer as running some version of Linux as the host.

Now, the point I would make is, it doesn't matter whether "Auto Resize guest Display" is enabled or not, the resulting display is similar. Only the resolution in the active area changes.

Since the graphics driver for the guest OS is provided by VirtualBox and not Nvidia, that is why I am looking here for a solution.

I hope someone can come up with an idea for solving this. It is very annoying to have to reboot the guest OS every time I turn the monitor off and then back on.

[Lewish]

P.S.

This problem does NOT occur when I use a lower resolution monitor (2560 x 1440), only on my 4K monitor.

[scottgus1]

The graphics driver for the guest only runs in the guest. It does not get any input from the host except if Guest Additions feeds info to change the guest screen size. If the host changes the particular video output's screen size when the attached 4K monitor is turned off, then the Guest Additions could pick up that size change and change the guest screen size. So far I don't see that Virtualbox is operating unusually.

The 4K vs 2560 x 1440 thing could be the issue. Which takes it back to the Host OS doing something unusual when the monitor is turned off.

I think before we call this a Virtualbox issue we should see the screen size change happen, as well as evidence that the status of "Auto Resize Guest Display" does not result in any difference in how the guest display responds. How to provide such evidence on your host is something you may have to figure out. Maybe a screen-grab video and a post to YouTube? I don't see this particular behavior happening on my hosts, With ARGD on, the guest changes size when the host window changes. When ARGD is off the guest display does not change size if the host window changes. After we see the evidence we may be able to say if Guest Additions are misinterpreting something.

[Lewish]

I upgraded from Debian jessie to Debian stretch a few days ago, and this problem seems to be solved. I have turned the monitor off at least a dozen times over the past days, and so far have not gotten a corrupted display in the Guest OS.

I have no idea what actually changed to solve the problem.

Thanks to all who tried to help.


Lewis