Seamless mode not in dual monitor

[Mitakuye]

I am using recent version, VirtualBoxVM 6.1 on a Win10 (home ed) 64bit host with a Linux Mint 19.1 Xfce guest.

When I start the Linux VM in "fullscreen mode", the 2 virtualbox screens show and I can drag windows inside Linux VM just as if it had dual monitors. Works great. However, this functionality removes once I selected virtualbox's "seamless mode".

Once I select "seamless mode", then all dual monitor functionality is removed. I can not even drag the seamless VM windows into my 2nd monitor, which I was able to do just fine while in "full screen mode".

Is there a way I can get this to work in "seamless mode" ?

[Mitakuye]

Also, while in "full screen mode", virtualbox's dual monitor 2nd window also automatically closed if I try to resize either monitor window. When I click "view" menu in virtualbox to enable 2nd monitor, all it does is resize my current window and does not open another window.

Why is it doing this?

[Mitakuye]

Well, after a few hours of playing around, the problem above still exists. I eventually figured out some workarounds (described below), but I would like to know how to do this properly so that I can use 3D Acceleration.

I found a workaround, but this workaround means I can not enable 3D Acceleration. The workaround is for me to change the "Graphic's Controller" setting to VBoxVGA, under "Display", from the virtual machine's "settings" window.

Once VBoxVGA is used, a 2nd VirtualBox window is created (allowed me to enable the monitor in the view menu) then allowing me to resize both VirtualBox windows to the size of my screens so to create the dual monitor, extended desktop workspace for seamless mode. So, now, when I go to seamless mode, everything works as it should, that is I am able to move the windows in an extended desktop, dual monitor environment.

However, quite annoying I am unable to launch programs from the VirtualBox "seamless mode" menu bar so I found a workaround for this. When in "seamless mode", I drag a window to the location of the guest OS's "start" button and this allows the "start" button to appear in seamless, which then I can start programs while in "seamless mode".

[scottgus1]

Sorry it seems no one is helping on this one. As for me I wouldn't know how to solve it. But someone might come along soon.

[mpack]

But someone might come along soon.

Yeah, but without a log they ain't gonna linger for long...

[fth0]

FWIW, the following hint can be found in the VirtualBox User Manual, at least in VirtualBox versions 5.2.x, 6.0.x and 6.1.x:

Neither scale mode nor seamless mode work correctly with guests using OpenGL 3D features, such as with Compiz-enabled window managers.

[mpack]

FWIW, the following hint can be found in the VirtualBox User Manual

Well spotted, I wasn't aware of that one. Mind you I seldom use seamless mode: I prefer to think of the VM as a separate PC. Happily, fullscreen mode works fine.

[Mitakuye]

But someone might come along soon.

Yeah, but without a log they ain't gonna linger for long...

..or, even if i do share the long, still not linger as in viewtopic.php?f=6&t=96281 (this author shared the log and nothing, basically same problem)

Apologize for my annoyance, I just got back to my home computer after traveling, so a bit tired right now. Actually, I am not missing the 3D Acceleration, but I have not had a context yet of where it is needed. So, right now, I am fine with the VBoxVGA graphics controller for VirtualBox. I also utilize VMWare Workstation Pro, which does not have this 3D Acceleration problem in seamless mode, but I like to utilize different hypervisors for more seperation, depending on what I need to get done. I might just use VMWare for when I encounter the necessity of 3D Acceleration in seamless mode.

FWIW, the following hint can be found in the VirtualBox User Manual, at least in VirtualBox versions 5.2.x, 6.0.x and 6.1.x:

Neither scale mode nor seamless mode work correctly with guests using OpenGL 3D features, such as with Compiz-enabled window managers.

So, is my desktop itself using OpenGL 3D features? when I was having the problem with the VMSVGA graphics controller, I was not executing anything other than resizing the virtualbox window.

FWIW, the following hint can be found in the VirtualBox User Manual

Well spotted, I wasn't aware of that one. Mind you I seldom use seamless mode: I prefer to think of the VM as a separate PC. Happily, fullscreen mode works fine.

Fullscreen works fine for me as well.

"Seamless" is nice when ya need to use multiple programs concurently from different environments without wasting screen workspace on the visuals of multiple desktops.

[Mitakuye]

FWIW, the following hint can be found in the VirtualBox User Manual, at least in VirtualBox versions 5.2.x, 6.0.x and 6.1.x:

Neither scale mode nor seamless mode work correctly with guests using OpenGL 3D features, such as with Compiz-enabled window managers.

Compiz core is removed from the Mint Xfce 32bit VM.

The VMSVGA seamless mode with dual display problem also exists with Mint Cinnamon 19.3 64bit (as guest OS), which does not use compiz.

Host OS is Windows 10 64bit.

[mpack]

At no time did I say that a log guarantees that someone offers a solution. I said that lack of one guarantees a fail.

[Mitakuye]

Well, I was curious if the free version of VMWare Workstation 15 Player allowed 3D Acceleration while in seamless mode, called "unity" in VMWare, Yep, it works like a charm.

I found my solution, if/when I need the 3D Acceleration.

Thanks for the mention about OpenGL. I will continue to see if reducing these 3D features on my Linux VM's will improve VirtualBox's stability for 3D Acceleration in seamless mode. I will report back if I find anything positive.

[BenP]

Hi, I have the same problem with my kubuntu hosted on win10.
I just solved it by choosing VBoxVGA instead of VMSVGA selected by default (no acceleration activated).
Hope this may help basic users like me .