「Separate X screen」の使用方法

「Separate X screen」用の xorg.conf は以下の通り。
説明はこの下に続く。

Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" RightOf "Screen0"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
InputDevice "Synaptics Touchpad"
EndSection

Section "Files"

# path to defoma fonts
#FontPath "/usr/share/fonts/X11/cyrillic"
FontPath "/usr/share/fonts/X11/misc"
FontPath "/usr/share/fonts/X11/100dpi/:unscaled"
FontPath "/usr/share/fonts/X11/75dpi/:unscaled"
FontPath "/usr/share/fonts/X11/Type1"
FontPath "/usr/share/fonts/X11/100dpi"
FontPath "/usr/share/fonts/X11/75dpi"
FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
Load "i2c"
Load "bitmap"
Load "ddc"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "vbe"
EndSection

Section "ServerFlags"
Option "Xinerama" "0"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "macintosh"
Option "XkbLayout" "en"
Option "XkbOptions" "lv3:rwin_switch"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ImPS/2"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "true"
EndSection

Section "InputDevice"
Identifier "Synaptics Touchpad"
Driver "synaptics"
Option "SendCoreEvents" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "SHMConfig" "true"
Option "LeftEdge" "150"
Option "RightEdge" "1070"
Option "TopEdge" "100"
Option "BottomEdge" "310"
Option "FingerLow" "25"
Option "FingerHigh" "30"
Option "MaxTapTime" "180"
Option "MaxTapMove" "220"
Option "SingleTapTimeout" "100"
Option "MaxDoubleTapTime" "180"
Option "LockedDrags" "off"
Option "MinSpeed" "1.10"
Option "MaxSpeed" "1.30"
Option "AccelFactor" "0.08"
Option "TapButton1" "0"
Option "TapButton2" "3"
Option "TapButton3" "0"
Option "RTCornerButton" "0"
Option "RBCornerButton" "0"
Option "LTCornerButton" "0"
Option "LBCornerButton" "0"
Option "VertScrollDelta" "20"
Option "HorizScrollDelta" "50"
Option "HorizEdgeScroll" "1"
Option "VertEdgeScroll" "1"
EndSection

Section "Monitor"
Identifier "Generic Monitor"
HorizSync 28.0 - 72.0
VertRefresh 43.0 - 60.0
Option "DPMS"
EndSection

Section "Monitor"
Identifier "Monitor1"
VendorName "Unknown"
ModelName "DELL E207WFP"
HorizSync 30.0 - 83.0
VertRefresh 56.0 - 75.0
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Apple Color LCD"
HorizSync 30.0 - 75.0
VertRefresh 60.0
EndSection

Section "Device"
Identifier "nVidia Corporation NVIDIA Default Card"
Driver "nvidia"
Option "AddARGBGLXVisuals" "True"
Option "NoLogo" "True"
EndSection

Section "Device"
Identifier "Videocard0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 8600M GT"
BusID "PCI:1:0:0"
Screen 0
EndSection

Section "Device"
Identifier "Videocard1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 8600M GT"
BusID "PCI:1:0:0"
Screen 1
EndSection

Section "Screen"
Identifier "Default Screen"
Device "nVidia Corporation NVIDIA Default Card"
Monitor "Generic Monitor"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1440x900" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "Screen"
# Removed Option "metamodes" "DFP: 1440x900 +0+0; DFP: 1024x768 +0+0; DFP: 800x600 +0+0; DFP: 640x480 +0+0"
Identifier "Screen1"
Device "Videocard1"
Monitor "Monitor1"
DefaultDepth 24
Option "TwinView" "0"
Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
EndSection

Section "Screen"
# Removed Option "TwinView" "1"
# Removed Option "metamodes" "CRT: 1024x768_60 +0+0, DFP: 1440x900 +1024+0; DFP: 1024x768 +0+0; DFP: 800x600 +0+0; DFP: 640x480 +0+0"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "0"
Option "metamodes" "DFP-0: 1440x900 +0+0; DFP-0: 1024x768 +0+0; DFP-0: 800x600 +0+0; DFP-0: 640x480 +0+0"
EndSection

Section "Extensions"
Option "Composite" "Enable"
EndSection

/etc/X11/xorg.conf_dualdisplay_separate
のように名前を付けておき、必要な時に /etc/X11/xorg.conf へコピーするが、使い勝手が悪いので、通常はこちらはあまり使用していない。
この設定では、xorg.conf を変更して X Window を再起動するまで常にデュアルディスプレイになってしまう。
シングルディスプレイに切り替えるには、xorg.conf を変更する必要があるため、毎回設定変更のたびに X Window の再起動が必要となる。
また、2台目のディスプレイのウィンドウマネージャが自動的に立ち上がらないため、ウィンドウ装飾が別途ウィンドウマネージャを機動する設定が必要となる。
2台目のディスプレイのウィンドウマネージャの起動方法は以下の通り。
2台目のディスプレイに画面が出てから実行すること。

$ DISPLAY=:0.1 gtk-window-decorator

（ただし、上記はGnomeを使用している場合に限る。KDEの場合はおそらく「$ DISPLAY=:0.1 kde-window-decorator」になる。）

以上のように「Separate X screen」は使い勝手が悪すぎる。（xorg.confの書き換えにroot権限も必要だしな。。。）