我在 OS X 10.11 主机上的 Virtualbox 5.0.6 上运行 Arch Linux 客户机，并安装了最新的客户机添加项。我使用 i3wm 作为桌面。
我已将 2 个虚拟监视器添加到我的虚拟机，但在调用命令时只能看到其中一个xrandr。客户添加项是否与 RandR 或 Xinerama 兼容？
这是xrandr的输出：
编辑
这是与 Virtualbox 驱动程序相关的 dmesg 摘录。我看不到任何加载错误。
[ 3.925977] vboxguest: misc device minor 58, IRQ 20, I/O port d020, MMIO at 00000000f0400000 (size 0x400000)
[ 3.925980] vboxguest: Successfully loaded version 5.0.6_OSE (interface 0x00010004)
[ 3.926371] systemd[1]: Starting Load/Save Random Seed...
[ 3.927860] systemd[1]: Starting Create Static Device Nodes in /dev...
[ 3.929689] systemd[1]: Mounted Huge Pages File System.
[ 3.949267] vboxsf: Successfully loaded version 5.0.6_OSE (interface 0x00010004)
[ 3.960095] [drm] Initialized drm 1.1.0 20060810
[ 3.961718] [drm] Initialized vboxvideo 1.0.0 20090303 for 0000:00:02.0 on minor 0
以下是与屏幕检测相关的 Xorg.0.log 摘录。最后三行有点令人不安，但它们表示不必在意...
[ 2129.737] (II) VBoxVideo(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 24/32
[ 2129.737] (==) VBoxVideo(0): Depth 24, (--) framebuffer bpp 32
[ 2129.737] (--) VBoxVideo(0): Virtual size is 32766x32766 (pitch 32766)
[ 2129.737] (**) VBoxVideo(0): Built-in mode "800x600": 29.3 MHz (scaled from 0.0 MHz), 36.4 kHz, 60.0 Hz
[ 2129.737] (II) VBoxVideo(0): Modeline "800x600"x0.0 29.31 800 802 804 806 600 602 604 606 (36.4 kHz b)
[ 2129.737] (**) VBoxVideo(0): Built-in mode "800x600": 29.3 MHz (scaled from 0.0 MHz), 36.4 kHz, 60.0 Hz
[ 2129.737] (II) VBoxVideo(0): Modeline "800x600"x0.0 29.31 800 802 804 806 600 602 604 606 (36.4 kHz b)
[ 2129.737] (II) VBoxVideo(0): vgaHWGetIOBase: hwp->IOBase is 0x03d0
[ 2129.737] (==) VBoxVideo(0): RGB weight 888
[ 2129.737] (==) VBoxVideo(0): Default visual is TrueColor
[ 2129.737] (==) VBoxVideo(0): Using gamma correction (1.0, 1.0, 1.0)
[ 2129.737] (==) VBoxVideo(0): DPI set to (96, 96)
[ 2129.737] (II) UnloadModule: "modesetting"
[ 2129.737] (II) Unloading modesetting
[ 2129.737] (--) Depth 24 pixmap format is 32 bpp
[ 2129.830] (II) VBoxVideo(0): Requested monitor count: 1
[ 2129.830] (II) VBoxVideo(0): Output VGA-0 using monitor section VGA-0
[ 2129.830] (**) VBoxVideo(0): Option "PreferredMode" "1920x1080"
[ 2129.830] (**) VBoxVideo(0): Option "Primary" "true"
[ 2129.830] (II) VBoxVideo(0): Output VGA-0 using monitor section VGA-0
[ 2129.830] (II) VBoxVideo(0): Printing probed modes for output VGA-0
[ 2129.830] (II) VBoxVideo(0): Modeline "1920x1080"x60.0 125.50 1920 1922 1924 1926 1080 1082 1084 1086 (65.2 kHz U
Pb)
[ 2129.830] (II) VBoxVideo(0): Modeline "800x600"x60.0 29.31 800 802 804 806 600 602 604 606 (36.4 kHz Pb)
[ 2129.830] (II) VBoxVideo(0): Modeline "2560x1600"x60.0 247.26 2560 2562 2564 2566 1600 1602 1604 1606 (96.4 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "2560x1440"x60.0 222.63 2560 2562 2564 2566 1440 1442 1444 1446 (86.8 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "2048x1536"x60.0 190.04 2048 2050 2052 2054 1536 1538 1540 1542 (92.5 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1920x1600"x60.0 185.59 1920 1922 1924 1926 1600 1602 1604 1606 (96.4 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1600x1200"x60.0 116.21 1600 1602 1604 1606 1200 1202 1204 1206 (72.4 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1680x1050"x60.0 106.82 1680 1682 1684 1686 1050 1052 1054 1056 (63.4 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1400x1050"x60.0 89.08 1400 1402 1404 1406 1050 1052 1054 1056 (63.4 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1280x1024"x60.0 79.47 1280 1282 1284 1286 1024 1026 1028 1030 (61.8 kHz b
)
[ 2129.830] (II) VBoxVideo(0): Modeline "1024x768"x60.0 47.83 1024 1026 1028 1030 768 770 772 774 (46.4 kHz b)
[ 2129.830] (II) VBoxVideo(0): Modeline "800x600"x60.0 29.31 800 802 804 806 600 602 604 606 (36.4 kHz b)
[ 2129.830] (II) VBoxVideo(0): Modeline "640x480"x60.0 18.84 640 642 644 646 480 482 484 486 (29.2 kHz b)
[ 2129.830] (II) VBoxVideo(0): Output VGA-0 connected
[ 2129.830] (II) VBoxVideo(0): Using user preference for initial modes
[ 2129.830] (II) VBoxVideo(0): Output VGA-0 using initial mode 1920x1080
[ 2129.830] (II) VBoxVideo(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated.
[ 2129.830] (II) VBoxVideo(0): RandR 1.2 enabled, ignore the following RandR disabled message.
[ 2129.831] (==) VBoxVideo(0): DPMS enabled
[ 2129.831] (--) RandR disabled