How can I get VirtualBox to play nicely with dual monitors?

Question

I use VirtualBox to run a Ubuntu x64 guest under a Vista x64 host with a 19" and 15" monitor.

I enable seamless mode in VirtualBox, but the windows don't actually move anywhere other than the desktop of the Ubuntu guest.

I'd also like fullscreen mode to display across both monitors.

How can I do this?

Answer 1

According to this forum post and looking through the VirtualBox release notes this is only available to Windows Guests. I know the latest 3 release introduced huge improvements on the 3D rendering side and with OpenGL. I would assume this would be available in the near future.

And according to the 4.0 release notes, the feature is available!

Guest Additions: support for multiple virtual screens in Linux and Solaris guests using X.Org server 1.3 and later

Answer 2

My solution involves running Ubuntu in headless mode and connecting through the Remote Desktop Connection tool. The display is full screen (no toolbars or menus) and spans both of my monitors. Here's what I did:

1. Double video memory to 16 MB in VirtualBox display settings for the machine. Also enable "Remote Display" server. For some reason I couldn't use the default port of 3389.

2. Run the machine in headless mode like this:

   VBoxHeadless.exe --startvm "Ubuntu 10.4 64-bit"

3. Connect to the machine using the Remote Desktop Connection tool that comes with Windows.

   mstsc /span /v:192.168.1.2:3390

Answer 3

Assuming you have the guest additions... You can get an approximate full screen across 2 monitors if you edit your xorg.conf file (I run FC11... I'm not sure if ubuntu uses xorg.conf?) and then just manually stretch the window to fill both. This definitely isnt ideal, but it does get you more visible desktop space.

I have two monitors in windows they run at 1440x900 and 1280x1024 respectively. The setup below allows a max screen size of 32000x32000.

You then just have to change the display and drag it out.

---------------/etc/X11/xorg.conf----------------------------------
 Default xorg.conf for Xorg 1.5+ without PCI_TXT_IDS_PATH enabled.
#
# This file was created by VirtualBox Additions installer as it
# was unable to find any existing configuration file for X.

Section "Device"
        Identifier      "Configured Video Device"
        Driver          "vboxvideo"
EndSection

Section "Screen"
    Identifier	"Default Screen"
    Monitor		"Generic Monitor"
    Device		"VirtualBox graphics card"
    DefaultDepth	24
    SubSection "Display"
      Depth	24
      Modes		"1440x900" "1280x1024" "2720x1024"
    EndSubSection
EndSection
---------------------------

Answer 4

As of VirtualBox 3.2.4, multiple monitor support is still only available for Windows guest operating systems. See the "Guest multi-monitor support" item in the Known Limitations chapter of the VirtualBox manual.

For Windows guests, apparently you just have to adjust the monitor count in the display settings or run in seamless mode. This post contains more details.