I have a Linux Mint (17.3) guest OS that works great for the most part (shared folders, networking, monitor resizing, etc). However, I am not able to enable more than one virtual monitor. On the host I have set the "Monitor Count" setting to two and restarted the guest for good measure. When the VBox guest window is not in fullscreen mode the View drop-down menu shows an enable option for Virtual Screen 2. However, nothing happens if I try to enable this additional monitor. In contrast, when the VBox guest window is in fullscreen mode the same drop-down menu shows the "Use Host Screen X" options for where to place the new virtual monitor. Again, however, nothing happens if I attempt to select any of these provided options. The only effect I observe is when I try to select the "Use Host Screen X" option to corresponds to the same physical monitor on which VBox is currently open. In this case the guest window will remove itself from fullscreen mode and then immediately go back into fullscreen mode.
I do have guest additions installed but am happy to provide whatever information necessary to verify this. Here are the bits that I know about:
I am using VirtualBox version 5.2.6 on the macOS host (10.12.6). I installed the guest additions by virtually inserting the ISO, but from the logs below it seems version 5.0.4 was installed.
A few xbox-related kernel modules are loaded:
Code: Select all
$ lsmod | grep box
vboxsf 45056 1
vboxguest 278528 7 vboxsf
vboxvideo 16384 1
drm 344064 3 vboxvideo
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[ 12.324950] vboxvideo: module verification failed: signature and/or required key missing - tainting kernel
[ 12.332003] [drm] Initialized vboxvideo 1.0.0 20090303 for 0000:00:02.0 on minor 0
[ 12.369277] vboxguest: misc device minor 56, IRQ 20, I/O port d020, MMIO at 00000000f0400000 (size 0x400000)
[ 12.369279] vboxguest: Successfully loaded version 5.0.4_LinuxMint (interface 0x00010004)
[ 14.142779] vboxsf: Successfully loaded version 5.0.4_LinuxMint (interface 0x00010004)
[ 14.144901] VBoxService 5.0.4_LinuxMint r102546 (verbosity: 0) linux.amd64 (Nov 10 2015 22:46:44) release log
[ 14.144901] 00:00:00.000051 main Log opened 2018-02-19T12:33:29.581446000Z
[ 14.144945] 00:00:00.000125 main OS Product: Linux
[ 14.144964] 00:00:00.000148 main OS Release: 3.19.0-32-generic
[ 14.144983] 00:00:00.000167 main OS Version: #37~14.04.1-Ubuntu SMP Thu Oct 22 09:41:40 UTC 2015
[ 14.145002] 00:00:00.000186 main OS Service Pack: #37~14.04.1-Ubuntu SMP Thu Oct 22 09:41:40 UTC 2015
[ 14.145025] 00:00:00.000204 main Executable: /usr/sbin/VBoxService
[ 14.145025] 00:00:00.000205 main Process ID: 1323
[ 14.145025] 00:00:00.000205 main Package type: LINUX_64BITS_GENERIC (OSE)
[ 14.146618] 00:00:00.001791 main 5.0.4_LinuxMint r102546 started. Verbose level = 0
[ 14.153613] 00:00:00.008772 automount VBoxServiceAutoMountWorker: Shared folder "vmshare" was mounted to "/media/sf_vmshare"