使用arandr

安装arandr，进入窗口系统后进行设置。这种图形化方法比较简单直观。但目前我还没有找到如何自动配置。

使用xrandr

VGA1 left of HDMI1 at their preferred resolutions

$ xrandr --output VGA1 --auto --output HDMI1 --auto --right-of VGA1

VGA1 right of HDMI1 at fixed resolutions

$ xrandr --output VGA1 --mode 1024x768 --pos 1920x0 --output HDMI1 --mode 1920x1080 --pos 0x0

使用xorg.conf

This is similar to using xrandr, separate Monitor section is needed for each screen. As an Identifier, the same value as reported by xrandr -q is used (i.e. Identifier "VGA1" is used instead of --output VGA1).
Example: dualhead configuration using relative coordinates

/etc/X11/xorg.conf.d/10-monitor.conf

Section "Monitor"
    Identifier  "VGA1"
    Option      "Primary" "true"
EndSection

Section "Monitor"
    Identifier  "HDMI1"
    Option      "LeftOf" "VGA1"
EndSection