Multiple Displays not working

[MikeInGenSan]

I have a Windows 10 PC host newly sent up with the extensions. [Version 6.1.28 r147628 (Qt5.6.2).]
The PC has four monitors. Two are on the system board's VGA and HDMI ports using the Intel HD 4000 graphics chip. The other two are on an old NVidia adapter also on VGA and HDMI. Three of the monitors are 1920x1080 and one is 1920x1200.

I set up a two clients. (A) Debian 11 client and (B) Windows 10 client. On both I sent the displays on the Client config on the Host to support multiple monitors.

But the actual General Display setting on both clients only lists one monitor as 'Virtual 1' and does not offer other monitors. In both cases, the resolutions for the monitors offered do not match the actual screens.

I attempted to install NVidia drivers for the Debian client but it reported if didn't find an NVidia adapter.

I read a post that I could set the resolution by running the following in C:\Program Files\Oracle\VirtualBox but the result was a corrupted client which I have removedand recreated.

Code: Select all

VBoxManage setextradata global GUI/MaxGuestResolution any
VBoxManage setextradata "Windows" "CustomVideoMode1" "1920 x 1080 x 16"
VBoxManage controlvm "Windows" setvideomodehint 1920 1080 16

I exported the Windows client to an OCI and imported it to a Debian Host but the video problem followed the client to the new host. Previous clients I had set up on Debian Hosts did not have any display resolution problem. I have never attempted to set up on a multi-display host before but it is really needed this time.

So, what am I doing wrong?

[scottgus1]

Guest Additions installed in the VMs are necessary for multiple displays. If you think you've done this already, please provide logs for the VMs:

Start each VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log and the hardening log next to it, zip them, and post the zip file, using the forum's Upload Attachment tab.

[MikeInGenSan]

Guest Additions installed in the VMs are necessary for multiple displays. If you think you've done this already, please provide logs for the VMs:

Start each VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log and the hardening log next to it, zip them, and post the zip file, using the forum's Upload Attachment tab.

I have read the manual "6.4. Installing the VirtualBox Guest Additions" and I have searched the Oracle site and find no downloadable file. I do find VirtualBox download site which provides the host code and the extension pack for the host "VirtualBox 6.1.28 Oracle VM VirtualBox Extension Pack" but no guest pack.

Please be so kind as to provide me with the URL on the Oracle site. I find sketchy third party sites but don't trust them.

[FrodoHobbits]

The Extension Pack is the Guest Additions

[MikeInGenSan]

The Extension Pack is the Guest Additions

From another user I was able to locate that the ISO was included in an download... but when I tried to load it I got:
http://ndevor.netwright.net/GAS-Error.PNG (If you don't that to click, it says it can't load because VERR_PDM_MEDIA_LOCKED)

But the file is not locked according to the host OS.

[mpack]

For VERR_PDM_MEDIA_LOCKED, consult Google.

[scottgus1]

Mike, you've got yourself down quite the rabbit hole.

Though the manual for Virtualbox is rather wordy sometimes, it does say here:
https://www.virtualbox.org/manual/ch04. ... dd-install

In the Devices menu in the virtual machine's menu bar, Oracle VM VirtualBox has a menu item Insert Guest Additions CD Image, which mounts the Guest Additions ISO file inside your virtual machine.

The GAs are not downloaded separately, they are bundled with Virtualbox, and clicking the VM window's Devices menu "Insert Guest Additions CD Image" will put the GAs "CD" into the VM's CD drive. You then run the GAs installer in the CD drive.

Further down the linked manual page, the Linux GAs have prerequisites https://www.virtualbox.org/manual/ch02. ... nux-prereq which are the same as for installing Virtualbox on a Linux host. Most often the prerequisites revolve around getting the Linux kernel headers installed first, then installing the Linux GAs.

The Extension Pack is the Guest Additions

Regrettably, this from FrodoHobbits is incorrect. Frodo probably meant:

The Extension Pack is not the Guest Additions

EP is not GAs. GAs comes with Virtualbox and goes into the guest, the VM. EP is a separate download and gets installed inside Virtualbox on the host. EP extends Virtualbox capabilities but is not needed for multiple monitors.

Re VERR_PDM_MEDIA_LOCKED, as Mpack recommends, try web-searching:

VERR_PDM_MEDIA_LOCKED site:forums.virtualbox.org

That's a common error for Linux VMs, and is discussed plethorically on the forum.

[sharpy1064]

Here's some other generic advice: Once you do get a second guest monitor / desktop, it can be a real problem to restore one of the windows if they get closed. If they do:

1. While the VM is still running, go to the guest window's View / Virtual Screen 2 and deselect the 'Enable' button
2. Restart the guest VM
3. Go back to the guest window's View / Virtual Screen 2 and select the 'Enable' button

Second window should appear