Difference between revisions of "Xorg"

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[[Category:X Server]]
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[[Category:X server]]
 
[[Category:Graphics]]
 
[[Category:Graphics]]
 
[[cs:Xorg]]
 
[[cs:Xorg]]
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[[ro:Xorg]]
 
[[ro:Xorg]]
 
[[ru:Xorg]]
 
[[ru:Xorg]]
[[tr:X_Sunucusu]]
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[[tr:X Sunucusu]]
 
[[zh-CN:Xorg]]
 
[[zh-CN:Xorg]]
 
[[zh-TW:Xorg]]
 
[[zh-TW:Xorg]]
{{Article summary start}}
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{{Related articles start}}
{{Article summary text|An all-inclusive overview about installing and managing Xorg}}
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{{Related|Start X at login}}
{{Article summary heading|Overview}}
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{{Related|Autostarting}}
{{Article summary text|{{Graphical user interface overview}}}}
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{{Related|Display manager}}
{{Article summary heading|Related}}
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{{Related|Window manager}}
{{Article summary wiki|Start X at Login}}
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{{Related|Font configuration}}
{{Article summary wiki|Execute commands after X start}}
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{{Related|Cursor themes}}
{{Article summary wiki|Display Manager}}
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{{Related|Desktop environment}}
{{Article summary wiki|Window Manager}}
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{{Related|Wayland}}
{{Article summary wiki|Font Configuration}}
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{{Related|Mir}}
{{Article summary wiki|Cursor Themes}}
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{{Related|Xinitrc}}
{{Article summary wiki|Desktop Environment}}
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{{Related articles end}}
{{Article summary wiki|Wayland}}
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{{Article summary heading|Free Video Drivers}}
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{{Article summary wiki|Intel Graphics}}
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{{Article summary wiki|ATI}}
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{{Article summary wiki|Nouveau}}
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{{Article summary heading|Proprietary Video Drivers}}
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{{Article summary wiki|AMD Catalyst}}
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{{Article summary wiki|NVIDIA}}
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{{Article summary end}}
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From http://www.x.org/wiki/:
 
From http://www.x.org/wiki/:
:''The X.Org project provides an open source implementation of the X Window System. The development work is being done in conjunction with the freedesktop.org community. The X.Org Foundation is the educational non-profit corporation whose Board serves this effort, and whose Members lead this work.''
+
:The X.Org project provides an open source implementation of the X Window System. The development work is being done in conjunction with the freedesktop.org community. The X.Org Foundation is the educational non-profit corporation whose Board serves this effort, and whose Members lead this work.
  
'''Xorg''' is the public, open-source implementation of the X window system version 11. Since Xorg is the most popular choice among Linux users, its ubiquity has led to making it an ever-present requisite for GUI applications, resulting in massive adoption from most distributions. See the [[Wikipedia:X.Org Server|Xorg]] Wikipedia article or visit the [http://www.x.org/wiki/ Xorg website] for more details.
+
'''Xorg''' is the most popular display server among Linux users. Its ubiquity has led to making it an ever-present requisite for GUI applications, resulting in massive adoption from most distributions. See the [[Wikipedia:X.Org Server|Xorg]] Wikipedia article or visit the [http://www.x.org/wiki/ Xorg website] for more details.
  
 
== Installation ==
 
== Installation ==
  
You will need to [[pacman|install]] the essential package {{Pkg|xorg-server}}, available in the [[Official Repositories]].
+
Xorg can be [[install]]ed with the {{Pkg|xorg-server}} package.
  
Additionally, some packages from the {{Grp|xorg-apps}} group are useful for certain configuration tasks, they are pointed out in the relevant section/page.
+
Additionally, some packages from the {{Pkg|xorg-server-utils}} meta-package are necessary for certain configuration tasks, they are pointed out in the relevant sections. Other useful packages are in the {{Grp|xorg-apps}} group.
  
{{Tip|The default X environment is rather bare, and you will typically seek to install a [[Window Manager|window manager]] or a [[Desktop Environment|desktop environment]] to supplement X.}}
+
{{Tip|You will typically seek to install a [[window manager]] or a [[desktop environment]] to supplement X.}}
  
 
=== Driver installation ===
 
=== Driver installation ===
 +
 +
{{Poor writing|Too cryptic for an introduction}}
  
 
The Linux kernel includes open-source video drivers and support for hardware accelerated framebuffers. However, userland support is required for OpenGL and 2D acceleration in X11.
 
The Linux kernel includes open-source video drivers and support for hardware accelerated framebuffers. However, userland support is required for OpenGL and 2D acceleration in X11.
Line 57: Line 50:
 
First, identify your card:
 
First, identify your card:
  
  $ lspci | grep VGA
+
  $ lspci | grep -e VGA -e 3D
  
 
Then install an appropriate driver. You can search the package database for a complete list of open-source video drivers:
 
Then install an appropriate driver. You can search the package database for a complete list of open-source video drivers:
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  $ pacman -Ss xf86-video
 
  $ pacman -Ss xf86-video
  
The default graphics driver is ''vesa'' (package {{Pkg|xf86-video-vesa}}), which handles a large number of chipsets but does not include any 2D or 3D acceleration. If a better driver cannot be found or fails to load, Xorg will fall back to ''vesa''.
+
Xorg searches for installed drivers automatically. If it cannot find the specific driver installed for the hardware (listed below), it first searches for ''fbdev'' ({{pkg|xf86-video-fbdev}}). If that is not found, it searches for ''vesa'' ({{pkg|xf86-video-vesa}}), the generic driver, which handles a large number of chipsets but does not include any 2D or 3D acceleration. If ''vesa'' is not found, Xorg will fall back to kernel mode setting, which includes GLAMOR acceleration (see {{ic|man modesetting}}).
  
 
In order for video acceleration to work, and often to expose all the modes that the GPU can set, a proper video driver is required:
 
In order for video acceleration to work, and often to expose all the modes that the GPU can set, a proper video driver is required:
 +
 +
{{Note|If you have a NVIDIA Optimus enabled laptop which uses an integrated video card combined with a dedicated GPU, see [[Bumblebee]].}}
  
 
{| class="wikitable"  style="text-align:center"
 
{| class="wikitable"  style="text-align:center"
 
|-
 
|-
! Brand !! Type !! Driver !! [[Multilib]] Package<br><span style="font-weight: normal; font-size: 0.8em;">(for 32-bit applications on Arch x86_64)</span> !! &nbsp;Documentation&nbsp;
+
! Brand !! Type !! Driver !! OpenGL !! OpenGL ([[Multilib]]) !! Documentation
 
|-
 
|-
| rowspan="2" bgcolor=#f7e3e3| '''<span style="color: #e62c2c;">&nbsp;AMD/ATI&nbsp;</span>'''
+
| rowspan="3" {{R|'''AMD/<br/>ATI'''}} || rowspan="2" | Open source || {{Pkg|xf86-video-amdgpu}} || rowspan="2" | {{Pkg|mesa-libgl}} || rowspan="2" | {{Pkg|lib32-mesa-libgl}} || [[AMDGPU]]
| &nbsp;Open source&nbsp; || {{Pkg|xf86-video-ati}} || {{Pkg|lib32-ati-dri}} || [[ATI]]
+
 
|-
 
|-
| Proprietary || {{AUR|catalyst-dkms}} || {{AUR|lib32-catalyst-utils}} || [[AMD Catalyst]]
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| {{Pkg|xf86-video-ati}} || [[ATI]]
 
|-
 
|-
| bgcolor=#e3ecf7| '''<span style="color: #2a6dc8;">Intel</span>'''
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| Proprietary || {{AUR|catalyst}} || {{AUR|catalyst-libgl}} || {{AUR|lib32-catalyst-libgl}} || [[AMD Catalyst]]
| Open source
+
| {{Pkg|xf86-video-intel}} || {{Pkg|lib32-intel-dri}} || [[Intel Graphics]]
+
 
|-
 
|-
| rowspan="6" bgcolor=#e3f7e6| '''<span style="color: #409044;">Nvidia</span>'''
+
| {{C|'''Intel'''}} || Open source || {{Pkg|xf86-video-intel}} || {{Pkg|mesa-libgl}} || {{Pkg|lib32-mesa-libgl}} || [[Intel graphics]]
| rowspan="2"| Open source
+
| {{Pkg|xf86-video-nouveau}} || {{Pkg|lib32-nouveau-dri}} || [[Nouveau]]
+
 
|-
 
|-
| {{Pkg|xf86-video-nv}} || || <span style="font-size: 0.9em;">(legacy driver)</span>
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| rowspan="4" {{G|'''Nvidia'''}} || Open source || {{Pkg|xf86-video-nouveau}} || {{Pkg|mesa-libgl}} || {{Pkg|lib32-mesa-libgl}} || [[Nouveau]]
 
|-
 
|-
| rowspan="4"| Proprietary || {{Pkg|nvidia}} || {{Pkg|lib32-nvidia-libgl}} || rowspan="4"| [[NVIDIA]]
+
| rowspan="3" | Proprietary || {{Pkg|nvidia}} || {{Pkg|nvidia-libgl}} || {{Pkg|lib32-nvidia-libgl}} || rowspan="3" | [[NVIDIA]]
 
|-
 
|-
| {{Pkg|nvidia-304xx}} || {{Pkg|lib32-nvidia-304xx-utils}}
+
| {{Pkg|nvidia-340xx}} || {{Pkg|nvidia-340xx-libgl}} || {{Pkg|lib32-nvidia-340xx-libgl}}
 
|-
 
|-
| {{AUR|nvidia-173xx}} || {{AUR|lib32-nvidia-173xx-utils}}
+
| {{Pkg|nvidia-304xx}} || {{Pkg|nvidia-304xx-libgl}} || {{Pkg|lib32-nvidia-304xx-libgl}}
|-
+
| {{AUR|nvidia-96xx}} || {{AUR|lib32-nvidia-96xx-utils}}
+
|-
+
| bgcolor=#f7f2e3| '''<span style="color: #9a4e16;">VIA</span>'''
+
| Open source || {{Pkg|xf86-video-openchrome}} || – || [[Via|VIA]]
+
 
|}
 
|}
  
Xorg should run smoothly without closed source drivers, which are typically needed only for advanced features such as fast 3D-accelerated rendering for games, dual-screen setups, and TV-out.
+
Other video drivers can be found in the {{Grp|xorg-drivers}} group.
 +
 
 +
Xorg should run smoothly without closed source drivers, which are typically needed only for advanced features such as fast 3D-accelerated rendering for games.
  
 
== Running ==
 
== Running ==
  
: ''See also: [[Start X at Login]]''
+
=== Display manager ===
  
{{Tip|The easiest way to start X is by using a [[Display Manager|display manager]] such as [[GDM]], [[KDM]] or [[SLiM]].}}
+
A convenient way to start X, but one that requires an additional application and dependencies, is by using a [[display manager]].
  
If you want to start X without a display manager, install the package {{Pkg|xorg-xinit}}. Optionally, the packages {{Pkg|xorg-twm}}, {{Pkg|xorg-xclock}} and {{Pkg|xterm}} allows for a default environment, as described below.
+
=== Manually ===
 
+
To start the X server without a display manager, see [[Xinitrc]].
The {{ic|startx}} and {{ic|xinit}} commands will start the X server and clients (the {{ic|startx}} script is merely a front end to the {{ic|xinit}} command). To determine the client to run, {{ic|startx}}/{{ic|xinit}} will first look to parse a {{ic|~/.xinitrc}} file in the user's home directory. In the absence of {{ic|~/.xinitrc}}, it defaults to the global file {{ic|/etc/X11/xinit/xinitrc}}, which defaults to starting a basic environment with the [[Twm]] window manager, [[Wikipedia:Xclock|Xclock]] and [[Xterm]]. For more information, see [[xinitrc]].
+
 
+
{{Note|
+
* X must always be run on the same tty where the login occurred, to preserve the logind session. This is handled by the default {{ic|/etc/X11/xinit/xserverrc}}. See [[General Troubleshooting#Session permissions]] for details.
+
* If a problem occurs, then view the log at {{ic|/var/log/Xorg.0.log}}. Be on the lookout for any lines beginning with {{ic|(EE)}}, which represent errors, and also {{ic|(WW)}}, which are warnings that could indicate other issues.
+
* If there is an ''empty'' {{ic|.xinitrc}} file in your {{ic|$HOME}}, either delete or edit it in order for X to start properly. If you do not do this X will show a blank screen with what appears to be no errors in your {{ic|Xorg.0.log}}. Simply deleting it will get it running with a default X environment.
+
}}
+
 
+
{{Warning|If you choose to use {{ic|xinit}} instead of {{ic|startx}}, you are responsible for passing {{ic|-nolisten tcp}} and ensuring the session does not break by starting X on a different tty.}}
+
  
 
== Configuration ==
 
== Configuration ==
  
{{Note|Arch supplies default configuration files in {{ic|/etc/X11/xorg.conf.d}}, and no extra configuration is necessary for most setups.}}
+
{{Note|Arch supplies default configuration files in {{ic|/usr/share/X11/xorg.conf.d}}, and no extra configuration is necessary for most setups.}}
  
 
Xorg uses a configuration file called {{ic|xorg.conf}} and files ending in the suffix {{ic|.conf}} for its initial setup: the complete list of the folders where these files are searched can be found at [http://www.x.org/releases/current/doc/man/man5/xorg.conf.5.xhtml] or by running {{ic|man xorg.conf}}, together with a detailed explanation of all the available options.
 
Xorg uses a configuration file called {{ic|xorg.conf}} and files ending in the suffix {{ic|.conf}} for its initial setup: the complete list of the folders where these files are searched can be found at [http://www.x.org/releases/current/doc/man/man5/xorg.conf.5.xhtml] or by running {{ic|man xorg.conf}}, together with a detailed explanation of all the available options.
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=== Using .conf files ===
 
=== Using .conf files ===
  
The {{ic|/etc/X11/xorg.conf.d/}} directory stores user-specific configuration. You are free to add configuration files there, but they must have a {{ic|.conf}} suffix: the files are read in ASCII order, and by convention their names start with {{ic|''XX''-}} (two digits and a hyphen, so that for example 10 is read before 20). These files are parsed by the X server upon startup and are treated like part of the traditional {{ic|xorg.conf}} configuration file. The X server essentially treats the collection of configuration files as one big file with entries from {{ic|xorg.conf}} at the end.
+
The {{ic|/etc/X11/xorg.conf.d/}} directory stores host-specific configuration. You are free to add configuration files there, but they must have a {{ic|.conf}} suffix: the files are read in ASCII order, and by convention their names start with {{ic|''XX''-}} (two digits and a hyphen, so that for example 10 is read before 20). These files are parsed by the X server upon startup and are treated like part of the traditional {{ic|xorg.conf}} configuration file. The X server essentially treats the collection of configuration files as one big file with entries from {{ic|xorg.conf}} at the end.
 +
 
 +
For option examples to set, see also the [http://fedoraproject.org/wiki/Input_device_configuration#xorg.conf.d fedora wiki].
  
 
=== Using xorg.conf ===
 
=== Using xorg.conf ===
Line 135: Line 115:
  
 
This should create a {{ic|xorg.conf.new}} file in {{ic|/root/}} that you can copy over to {{ic|/etc/X11/xorg.conf}}.
 
This should create a {{ic|xorg.conf.new}} file in {{ic|/root/}} that you can copy over to {{ic|/etc/X11/xorg.conf}}.
 +
 +
{{Tip|If you are already running an X server, use a different display, for example {{ic|Xorg :2 -configure}}.}}
  
 
Alternatively, your proprietary video card drivers may come with a tool to automatically configure Xorg: see the article of your video driver, [[NVIDIA]] or [[AMD Catalyst]], for more details.
 
Alternatively, your proprietary video card drivers may come with a tool to automatically configure Xorg: see the article of your video driver, [[NVIDIA]] or [[AMD Catalyst]], for more details.
Line 140: Line 122:
 
{{Note|Configuration file keywords are case insensitive, and "_" characters are ignored. Most strings (including Option names) are also case insensitive, and insensitive to white space and "_" characters.}}
 
{{Note|Configuration file keywords are case insensitive, and "_" characters are ignored. Most strings (including Option names) are also case insensitive, and insensitive to white space and "_" characters.}}
  
=== Sample configurations ===
+
== Input devices ==
  
'''{{ic|xorg.conf}}'''
+
For input devices, the virtual package ''xf86-input-driver'' ensures at least one input driver of either {{Pkg|xf86-input-evdev}} or {{Pkg|xf86-input-libinput}} is installed.[https://www.archlinux.org/news/xorg-1180-enters-testing/]  
# [http://pastebin.com/raw.php?i=EuSKahkn Sample 1]
+
#* {{Note|Sample configuration file using {{ic|/etc/X11/xorg.conf.d/10-evdev.conf}} for the keyboard layouts. Note the commented out {{ic|InputDevice}} sections.}}
+
'''{{ic|/etc/X11/xorg.conf.d/10-evdev.conf}}'''
+
# [http://pastebin.com/raw.php?i=4mPY35Mw Sample 1]
+
#* {{Note|This is the {{ic|10-evdev.conf}} file that goes with the xorg.conf sample 1.}}
+
'''{{ic|/etc/X11/xorg.conf.d/10-monitor.conf}}'''
+
# [http://pastebin.com/raw.php?i=fJv8EXGb VMware]
+
# [http://pastebin.com/raw.php?i=NRz7v0Kn KVM]
+
# [https://gist.github.com/daemox/6325050 NVIDIA]
+
#* {{Note|nvidia-ck binary drivers (v325); Dual GPU, Dual Monitor, Dual Screen; No Twinview, No Xinerama; Rotated and vertically placed screen1 above screen0.}}
+
  
== Input devices ==
+
[[Udev]], which is provided as a systemd dependency, will detect your hardware and both drivers will act as hotplugging input driver for almost all devices, as defined in the default configuration files {{ic|10-evdev.conf}} and {{ic|60-libinput.conf}} in the {{ic|/usr/share/X11/xorg.conf.d/}} directory.
  
[[Udev]] will detect your hardware and [[Wikipedia:evdev|evdev]] will act as the hotplugging input driver for almost all devices. Udev is provided by {{Pkg|systemd}} and {{Pkg|xf86-input-evdev}} is required by {{Pkg|xorg-server}}, so there is no need to explicitly install those packages. If evdev does not support your device, install the needed driver from the {{Grp|xorg-drivers}} group.
+
After starting X server, the log file will show which driver hotplugged for the individual devices (note the most recent log file name may vary):
 +
$ grep -e "Using input driver " ~/.local/share/xorg/Xorg.0.log
  
You should have {{ic|10-evdev.conf}} in the {{ic|/etc/X11/xorg.conf.d/}} directory, which manages keyboards, mice, touchpads and touchscreens.
+
If both do not support a particular device, install the needed driver from the {{Grp|xorg-drivers}} group. The same applies, if you want to use another driver.  
  
See the following pages for specific instructions, or the [https://fedoraproject.org/wiki/Input_device_configuration Fedora wiki] entry for more examples.
+
To influence hotplugging, see [[#Configuration]].
 +
 
 +
For specific instructions, see also the [[libinput]] article, the following pages below, or the [https://fedoraproject.org/wiki/Input_device_configuration Fedora wiki] entry for more examples.
  
 
=== Mouse acceleration ===
 
=== Mouse acceleration ===
  
See the main page: [[Mouse acceleration]]
+
See [[Mouse acceleration]].
  
 
=== Extra mouse buttons ===
 
=== Extra mouse buttons ===
  
See the main page: [[All Mouse Buttons Working]]
+
See [[All Mouse Buttons Working]].
 +
 
 +
=== Touchpad ===
 +
 
 +
See [[Synaptics]] or [[libinput]].
  
=== Touchpad Synaptics ===
+
=== Touchscreen ===
  
See the main page: [[Touchpad Synaptics]]
+
See [[Touchscreen]].
  
 
=== Keyboard settings ===
 
=== Keyboard settings ===
  
See the main page: [[Keyboard Configuration in Xorg]]
+
See [[Keyboard configuration in Xorg]].
  
 
== Monitor settings ==
 
== Monitor settings ==
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EndSection
 
EndSection
 
</nowiki>}}
 
</nowiki>}}
 +
 +
{{Note|By default, Xorg needs to be able to detect a monitor and will not start otherwise. A workaround is to create a configuration file such as the example above and thus avoid auto-configuring. A common case where this is necessary is a headless system, which boots without a monitor and starts Xorg automatically, either from a [[Automatic login to virtual console|virtual console]] at [[Start X at login|login]], or from a [[display manager]].}}
  
 
=== Multiple monitors ===
 
=== Multiple monitors ===
Line 216: Line 197:
 
* [[Nouveau#Dual Head]]
 
* [[Nouveau#Dual Head]]
 
* [[AMD Catalyst#Double Screen (Dual Head / Dual Screen / Xinerama)]]
 
* [[AMD Catalyst#Double Screen (Dual Head / Dual Screen / Xinerama)]]
* [[ATI#Dual Head setup]]
+
* [[ATI#Multihead setup]]
  
 
==== More than one graphics card ====
 
==== More than one graphics card ====
Line 292: Line 273:
  
 
==== Setting DPI manually ====
 
==== Setting DPI manually ====
 +
 +
{{Note|While you can set any dpi you like and applications using Qt and GTK will scale accordingly, it's recommended to set it to 96, 120 (25% higher), 144 (50% higher), 168 (75% higher), 192 (100% higher) etc., to reduce scaling artifacts to GUI that use bitmaps. Reducing it below 96 dpi may not reduce size of graphical elements of GUI as typically the lowest dpi the icons are made for is 96.}}
 +
 +
For RandR compliant drivers (for example the open source ATI driver), you can set it by:
 +
 +
$ xrandr --dpi 144
 +
 +
{{Note|Applications that comply with the setting will not change immediately. You have to start them anew.}}
 +
 +
See [[Execute commands after X start]] to make it permanent.
 +
 +
===== Proprietary NVIDIA driver =====
  
 
DPI can be set manually if you only plan to use one resolution ([http://pxcalc.com/ DPI calculator]):
 
DPI can be set manually if you only plan to use one resolution ([http://pxcalc.com/ DPI calculator]):
Line 302: Line 295:
 
}}
 
}}
  
If you use an NVIDIA card, you can manually set the DPI adding the options bellow on {{ic|/etc/X11/xorg.conf.d/20-nvidia.conf}} (inside '''Device''' section):
+
You can manually set the DPI adding the options below on {{ic|/etc/X11/xorg.conf.d/20-nvidia.conf}} (inside '''Device''' section):
  
 
  Option              "UseEdidDpi" "False"
 
  Option              "UseEdidDpi" "False"
 
  Option              "DPI" "96 x 96"
 
  Option              "DPI" "96 x 96"
 
For RandR compliant drivers, you can set it by:
 
 
$ xrandr --dpi 96
 
 
See [[Execute commands after X start]] to make it permanent.
 
 
{{Note|While you can set any dpi you like and applications using Qt and GTK will scale accordingly, it's recommended to set it to 96, 120 (25% higher), 144 (50% higher), 168 (75% higher), 192 (100% higher) etc., to reduce scaling artifacts to GUI that use bitmaps. Reducing it below 96 dpi may not reduce size of graphical elements of GUI as typically the lowest dpi the icons are made for is 96.}}
 
  
 
=== DPMS ===
 
=== DPMS ===
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== Composite ==
 
== Composite ==
  
The Composite extension for X causes an entire sub-tree of the window hierarchy to be rendered to an off-screen buffer. Applications can then take the contents of that buffer and do whatever they like. The off-screen buffer can be automatically merged into the parent window or merged by external programs, called compositing managers. See the following page for more info.
+
The Composite extension for X causes an entire sub-tree of the window hierarchy to be rendered to an off-screen buffer. Applications can then take the contents of that buffer and do whatever they like. The off-screen buffer can be automatically merged into the parent window or merged by external programs, called compositing managers. See the following article for more information: [[Wikipedia:Compositing window manager|compositing window manager]]
  
*[[Compiz]] -- The original composite/window manager from Novell
+
Some window managers (e.g. [[Compiz]], [[Enlightenment]], KWin, Marco, Metacity, Muffin, Mutter, [[Xfwm]]) do compositing on their own. For other window managers, a standalone composite manager can be used.
*[[Xcompmgr]] -- A simple composite manager capable of drop shadows and primitive transparency
+
 
*[[Compton]] -- A fork of [[xcompmgr]] with feature improves and bug fix
+
=== List of composite managers ===
*[[Cairo Compmgr|Cairo Composite Manager]] -- A versatile and extensible composite manager which uses cairo for rendering.
+
 
*[[Wikipedia:Compositing window manager]]
+
* {{App|[[Cairo Compmgr|Cairo Composite Manager]]|Cairo based composite manager|http://cairo-compmgr.tuxfamily.org/|{{AUR|cairo-compmgr-git}}}}
 +
* {{App|[[Compton]]|Compositor (a fork of xcompmgr-dana)|https://github.com/chjj/compton|{{Pkg|compton}}}}
 +
* {{App|[[Xcompmgr]]|Composite window-effects manager|http://cgit.freedesktop.org/xorg/app/xcompmgr/|{{Pkg|xcompmgr}}}}
 +
* {{App|Unagi|Modular compositing manager which aims written in C and based on XCB|http://projects.mini-dweeb.org/projects/unagi|{{AUR|unagi}}}}
  
 
== Tips and tricks ==
 
== Tips and tricks ==
  
 
=== X startup tweaking (startx) ===
 
=== X startup tweaking (startx) ===
 +
 +
{{Accuracy|{{ic|/usr/bin/startx}} should not be modified, ''startx'' recognises the options as command line arguments}}
  
 
For X's option reference see:
 
For X's option reference see:
Line 344: Line 334:
  
 
=== Nested X session ===
 
=== Nested X session ===
 +
 +
{{Expansion|mention [[Awesome#Using_Xephyr|xephyr]]}}
  
 
To run a nested session of another desktop environment:
 
To run a nested session of another desktop environment:
Line 360: Line 352:
 
With the help of ''xinput'' you can temporarily disable or enable input sources. This might be useful, for example, on systems that have more than one mouse, such as the ThinkPads and you would rather use just one to avoid unwanted mouse clicks.
 
With the help of ''xinput'' you can temporarily disable or enable input sources. This might be useful, for example, on systems that have more than one mouse, such as the ThinkPads and you would rather use just one to avoid unwanted mouse clicks.
  
[[pacman|Install]] the {{Pkg|xorg-xinput}} package from the [[Official Repositories|official repositories]].
+
[[Install]] the {{Pkg|xorg-xinput}} package from the [[official repositories]].
  
Find the ID of the device you want to disable:
+
Find the name or ID of the device you want to disable:
  
 
  $ xinput
 
  $ xinput
Line 382: Line 374:
 
</nowiki>}}
 
</nowiki>}}
  
Disable the device with {{ic|xinput --disable ''device_id''}}, where ''device_id'' is the device ID you want to disable. In this example we will disable the Synaptics Touchpad, with the ID 10:
+
Disable the device with {{ic|xinput --disable ''device''}}, where ''device'' is the device ID or name of the device you want to disable. In this example we will disable the Synaptics Touchpad, with the ID 10:
  
 
  $ xinput --disable 10
 
  $ xinput --disable 10
Line 389: Line 381:
  
 
  $ xinput --enable 10
 
  $ xinput --enable 10
 +
 +
Alternatively using the device name, the command to disable the touchpad would be:
 +
 +
$ xinput --disable "SynPS/2 Synaptics TouchPad"
 +
 +
=== Killing application with hotkey ===
 +
Run script on hotkey:
 +
 +
#!/bin/bash
 +
windowFocus=$(xdotool getwindowfocus);
 +
pid=$(xprop -id $windowFocus | grep PID);
 +
kill -9 $pid
 +
 +
Deps: {{Pkg|xorg-xprop}}, {{Pkg|xdotool}}
  
 
== Troubleshooting ==
 
== Troubleshooting ==
  
=== Common problems ===
+
=== General ===
 +
 
 +
If a problem occurs, view the log stored in either {{ic|/var/log/}} or, for the rootless X default since v1.16, in {{ic|~/.local/share/xorg/}}. [[GDM]] users should check the [[systemd]] journal. [https://bbs.archlinux.org/viewtopic.php?id=184639]
 +
 
 +
The logfiles are of the form {{ic|Xorg.n.log}} with {{ic|n}} being the display number. For a single user machine with default configuration the applicable log is frequently {{ic|Xorg.0.log}}, but otherwise it may vary. To make sure to pick the right file it may help to look at the timestamp of the X server session start and from which console it was started. For example:
 +
 
 +
{{hc|1=$ grep -e Log -e tty Xorg.0.log|2=[    40.623] (==) Log file: "/home/archuser/.local/share/xorg/Xorg.0.log", Time: Thu Aug 28 12:36:44 2014
 +
[    40.704] (--) controlling tty is VT number 1, auto-enabling KeepTty}}
 +
 
 +
* In the logfile then be on the lookout for any lines beginning with {{ic|(EE)}}, which represent errors, and also {{ic|(WW)}}, which are warnings that could indicate other issues.
 +
 
 +
* If there is an ''empty'' {{ic|.xinitrc}} file in your {{ic|$HOME}}, either delete or edit it in order for X to start properly. If you do not do this X will show a blank screen with what appears to be no errors in your {{ic|Xorg.0.log}}. Simply deleting it will get it running with a default X environment.
 +
* If the screen goes black, you may still attempt to switch to a different virtual console (e.g. {{ic|Ctrl+Alt+F2}}), and blindly log in as root. You can do this by typing {{ic|root}} (press {{ic|Enter}} after typing it) and entering the root password (again, press {{ic|Enter}} after typing it).
 +
 
 +
: You may also attempt to kill the X server with:
 +
: {{bc|# pkill X}}
 +
: If this does not work, reboot blindly with:
 +
: {{bc|# reboot}}
  
If Xorg will not start, the screen is completely black, the keyboard and mouse are not working, etc., first take these simple steps:
 
*Check the log file: {{ic|cat /var/log/Xorg.0.log}}
 
 
*Check specific pages in [[:Category:Input devices]] if you have issues with keyboard, mouse, touchpad etc.
 
*Check specific pages in [[:Category:Input devices]] if you have issues with keyboard, mouse, touchpad etc.
*Finally, search for common problems in [[ATI]], [[Intel]] and [[NVIDIA]] articles.
+
*Search for common problems in [[ATI]], [[Intel]] and [[NVIDIA]] articles.
 +
 
 +
=== Black screen, No protocol specified.., Resource temporarily unavailable for all or some users ===
 +
 
 +
X creates configuration and temporary files in current user's home directory. Make sure there is free disk space available on the partition your home directory resides in. Unfortunately, X server does not provide any more obvious information about lack of disk space in this case.
  
 
=== CTRL right key does not work with oss keymap ===
 
=== CTRL right key does not work with oss keymap ===
 +
 +
{{Accuracy|The file will be overwritten on {{Pkg|xkeyboard-config}} update; for such simple task should be used [[Xmodmap]].}}
  
 
Edit as root {{ic|/usr/share/X11/xkb/symbols/fr}}, and change the line:
 
Edit as root {{ic|/usr/share/X11/xkb/symbols/fr}}, and change the line:
Line 409: Line 436:
 
  // include "level5(rctrl_switch)"
 
  // include "level5(rctrl_switch)"
  
Then restart X or reboot.
+
Then restart X, reboot or run
  
=== X clients started with "su" fail ===
+
setxkbmap fr oss
  
If you are getting "Client is not authorized to connect to server", try adding the line:
+
=== DRI with Matrox cards stops working ===
  
session        optional        pam_xauth.so
+
If you use a Matrox card and DRI stops working after upgrading to Xorg, try adding the line:
  
to {{ic|/etc/pam.d/su}}. {{ic|pam_xauth}} will then properly set environment variables and handle {{ic|xauth}} keys.
+
Option "OldDmaInit" "On"
  
=== Program requests "font '(null)'" ===
+
to the Device section that references the video card in {{ic|xorg.conf}}.
 
+
* Error message: "''unable to load font `(null)'.''"
+
Some programs only work with bitmap fonts. Two major packages with bitmap fonts are available, {{Pkg|xorg-fonts-75dpi}} and {{Pkg|xorg-fonts-100dpi}}. You do not need both; one should be enough. To find out which one would be better in your case, try this:
+
 
+
$ xdpyinfo | grep resolution
+
 
+
and use what is closer to you (75 or 100 instead of XX)
+
 
+
# pacman -S xorg-fonts-XXdpi
+
  
 
=== Frame-buffer mode problems ===
 
=== Frame-buffer mode problems ===
Line 448: Line 466:
 
</nowiki>}}
 
</nowiki>}}
  
uninstall fbdev:
+
[[Uninstall]] the {{pkg|xf86-video-fbdev}} package.
  
# pacman -R xf86-video-fbdev
+
=== Launching multiple X sessions with proprietary NVIDIA on Xorg 1.16 ===
  
=== DRI with Matrox cards stops working ===
+
When attempting to launch X sessions in multiple ttys on Xorg 1.16, you may be rejected with a log indicating that no drivers were found. I found that a workaround for this was to specifically tell X that we'd like to use the 'nvidia' driver.
  
If you use a Matrox card and DRI stops working after upgrading to Xorg, try adding the line:
+
{{ic|/etc/X11/xorg.conf.d/20-nvidia.conf}}
 +
Section "Device"
 +
    Identifier "Device0"
 +
    Driver    "nvidia"
 +
    VendorName "NVIDIA Corporation"
 +
    Option    "NoLogo" "True"
 +
EndSection
  
Option "OldDmaInit" "On"
+
=== Program requests "font '(null)'" ===
  
to the Device section that references the video card in {{ic|xorg.conf}}.
+
* Error message: "''unable to load font `(null)'.''"
 +
Some programs only work with bitmap fonts. Two major packages with bitmap fonts are available, {{Pkg|xorg-fonts-75dpi}} and {{Pkg|xorg-fonts-100dpi}}. You do not need both; one should be enough. To find out which one would be better in your case, try this:
 +
 
 +
$ xdpyinfo | grep resolution
 +
 
 +
and use what is closer to the shown value.
  
 
=== Recovery: disabling Xorg before GUI login ===
 
=== Recovery: disabling Xorg before GUI login ===
Line 465: Line 494:
  
 
* Change default target to rescue.target. See [[systemd#Change default target to boot into]].
 
* Change default target to rescue.target. See [[systemd#Change default target to boot into]].
* If you have not only a faulty system that makes Xorg unusable, but you have also set the GRUB menu wait time to zero, or cannot otherwise use GRUB to prevent Xorg from booting, you can use the Arch Linux live CD. Boot up the live CD and log in as root. You need a mount point, such as {{ic|/mnt}}, and you need to know the name of the partition you want to mount.
+
* If you have not only a faulty system that makes Xorg unusable, but you have also set the GRUB menu wait time to zero, or cannot otherwise use GRUB to prevent Xorg from booting, you can use the Arch Linux live CD. Follow the [[Installation_guide#Mount_the_partitions|installation guide]] about how to mount and chroot into the installed Arch Linux. Alternatively try to switch into another [[Getty|tty]] with {{ic|Ctrl+Alt}} + function key (usually from {{ic|F1}} to {{ic|F7}} depending on which is not used by X), login as root and follow steps below.
  
You can use the command,
+
Depending on setup, you will need to do one or more of these steps:
  
# fdisk -l
+
* [[Disable]] the [[display manager]].
 +
* Disable the [[start X at login|automatic start of the X]].
 +
* Rename the {{ic|~/.xinitrc}} or comment out the {{ic|exec}} line in it.
  
to see your partitions. Usually, the one you want will be resembling {{ic|/dev/sda1}}. Then, to mount this to {{ic|/mnt}}, use
+
=== X clients started with "su" fail ===
  
# mount /dev/sda1 /mnt
+
If you are getting "Client is not authorized to connect to server", try adding the line:
  
Then your filesystem will show up under {{ic|/mnt}}. From here you can delete the {{ic|gdm}} daemon to prevent Xorg from booting up normally or make any other necessary changes to the configuration.
+
session        optional        pam_xauth.so
 +
 
 +
to {{ic|/etc/pam.d/su}}. {{ic|pam_xauth}} will then properly set environment variables and handle {{ic|xauth}} keys.
  
 
=== X failed to start: Keyboard initialization failed ===
 
=== X failed to start: Keyboard initialization failed ===
Line 481: Line 514:
 
If your hard disk is full, startx will fail. {{ic|/var/log/Xorg.0.log}} will end with:
 
If your hard disk is full, startx will fail. {{ic|/var/log/Xorg.0.log}} will end with:
  
{{bc|
+
{{bc|<nowiki>
 
(EE) Error compiling keymap (server-0)
 
(EE) Error compiling keymap (server-0)
 
(EE) XKB: Could not compile keymap
 
(EE) XKB: Could not compile keymap
Line 491: Line 524:
 
Fatal server error:
 
Fatal server error:
 
Failed to activate core devices.
 
Failed to activate core devices.
Please consult the The X.Org Foundation support at http://wiki.x.org
+
Please consult the The X.Org Foundation support at http://wiki.x.org
 
for help.
 
for help.
 
Please also check the log file at "/var/log/Xorg.0.log" for additional information.
 
Please also check the log file at "/var/log/Xorg.0.log" for additional information.
 
(II) AIGLX: Suspending AIGLX clients for VT switch
 
(II) AIGLX: Suspending AIGLX clients for VT switch
}}
+
</nowiki>}}
  
 
Make some free space on your root partition and X will start.
 
Make some free space on your root partition and X will start.
  
=== Black screen, No protocol specified.., Resource temporarily unavailable for all or some users ===
+
=== Rootless Xorg (v1.16) ===
  
X creates configuration and temporary files in current user's home directory. Make sure there is free disk space available on the partition your home directory resides in. Unfortunately, X server does not provide any more obvious information about lack of disk space in this case.
+
As of version 1.16 [https://www.archlinux.org/news/xorg-server-116-is-now-available/], Xorg may run with standard user privileges with the help of {{ic|logind}}. The requirements for this are:
 +
 
 +
* [[systemd]]; version >=216 for multiple instances
 +
* Starting X via [[xinit]]; display managers are not supported
 +
* [[Kernel mode setting]]; implementations in proprietary display drivers fail [http://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/xorg-wrapper.c#n222 auto-detection] and require manually setting {{ic|1=needs_root_rights = no}} in {{ic|/etc/X11/Xwrapper.config}}.
 +
 
 +
If you do not fit these requirements, re-enable root rights in {{ic|/etc/X11/Xwrapper.config}}:
 +
 
 +
needs_root_rights = ''yes''
 +
 
 +
See also [http://manned.org/Xorg.wrap.1 Xorg.wrap(1)] and [[Systemd/User#Xorg as a systemd user service]].
 +
 
 +
==== Broken redirection ====
 +
 
 +
While user Xorg logs are stored in {{ic|~/.local/share/xorg/Xorg.log}}, they do not include the output from the X session. To re-enable redirection, start X with the {{ic|-keeptty}} flag:
 +
 
 +
exec startx -- -keeptty -nolisten tcp > ~/.xorg.log 2>&1
 +
 
 +
Or copy {{ic|/etc/X11/xinit/xserverrc}} to {{ic|~/.xserverrc}}, and append {{ic|-keeptty}}. See [https://bbs.archlinux.org/viewtopic.php?pid=1446402#p1446402].
 +
 
 +
=== Why do I get a green screen whenever I try to watch a video?===
 +
 
 +
Your color depth is set wrong. It may need to be 24 instead of 16, for example.
 +
 
 +
=== SocketCreateListener error ===
 +
 
 +
If X terminates with error message "SocketCreateListener() failed", you may need to delete socket files in {{ic|/tmp/.X11-unix}}. This may happen if you have previously run Xorg as root (e.g. to generate an {{ic|xorg.conf}}).

Latest revision as of 12:19, 28 June 2016

From http://www.x.org/wiki/:

The X.Org project provides an open source implementation of the X Window System. The development work is being done in conjunction with the freedesktop.org community. The X.Org Foundation is the educational non-profit corporation whose Board serves this effort, and whose Members lead this work.

Xorg is the most popular display server among Linux users. Its ubiquity has led to making it an ever-present requisite for GUI applications, resulting in massive adoption from most distributions. See the Xorg Wikipedia article or visit the Xorg website for more details.

Installation

Xorg can be installed with the xorg-server package.

Additionally, some packages from the xorg-server-utils meta-package are necessary for certain configuration tasks, they are pointed out in the relevant sections. Other useful packages are in the xorg-apps group.

Tip: You will typically seek to install a window manager or a desktop environment to supplement X.

Driver installation

Tango-edit-clear.pngThis article or section needs language, wiki syntax or style improvements.Tango-edit-clear.png

Reason: Too cryptic for an introduction (Discuss in Talk:Xorg#)

The Linux kernel includes open-source video drivers and support for hardware accelerated framebuffers. However, userland support is required for OpenGL and 2D acceleration in X11.

First, identify your card:

$ lspci | grep -e VGA -e 3D

Then install an appropriate driver. You can search the package database for a complete list of open-source video drivers:

$ pacman -Ss xf86-video

Xorg searches for installed drivers automatically. If it cannot find the specific driver installed for the hardware (listed below), it first searches for fbdev (xf86-video-fbdev). If that is not found, it searches for vesa (xf86-video-vesa), the generic driver, which handles a large number of chipsets but does not include any 2D or 3D acceleration. If vesa is not found, Xorg will fall back to kernel mode setting, which includes GLAMOR acceleration (see man modesetting).

In order for video acceleration to work, and often to expose all the modes that the GPU can set, a proper video driver is required:

Note: If you have a NVIDIA Optimus enabled laptop which uses an integrated video card combined with a dedicated GPU, see Bumblebee.
Brand Type Driver OpenGL OpenGL (Multilib) Documentation
AMD/
ATI
Open source xf86-video-amdgpu mesa-libgl lib32-mesa-libgl AMDGPU
xf86-video-ati ATI
Proprietary catalystAUR catalyst-libglAUR lib32-catalyst-libglAUR AMD Catalyst
Intel Open source xf86-video-intel mesa-libgl lib32-mesa-libgl Intel graphics
Nvidia Open source xf86-video-nouveau mesa-libgl lib32-mesa-libgl Nouveau
Proprietary nvidia nvidia-libgl lib32-nvidia-libgl NVIDIA
nvidia-340xx nvidia-340xx-libgl lib32-nvidia-340xx-libgl
nvidia-304xx nvidia-304xx-libgl lib32-nvidia-304xx-libgl

Other video drivers can be found in the xorg-drivers group.

Xorg should run smoothly without closed source drivers, which are typically needed only for advanced features such as fast 3D-accelerated rendering for games.

Running

Display manager

A convenient way to start X, but one that requires an additional application and dependencies, is by using a display manager.

Manually

To start the X server without a display manager, see Xinitrc.

Configuration

Note: Arch supplies default configuration files in /usr/share/X11/xorg.conf.d, and no extra configuration is necessary for most setups.

Xorg uses a configuration file called xorg.conf and files ending in the suffix .conf for its initial setup: the complete list of the folders where these files are searched can be found at [1] or by running man xorg.conf, together with a detailed explanation of all the available options.

Using .conf files

The /etc/X11/xorg.conf.d/ directory stores host-specific configuration. You are free to add configuration files there, but they must have a .conf suffix: the files are read in ASCII order, and by convention their names start with XX- (two digits and a hyphen, so that for example 10 is read before 20). These files are parsed by the X server upon startup and are treated like part of the traditional xorg.conf configuration file. The X server essentially treats the collection of configuration files as one big file with entries from xorg.conf at the end.

For option examples to set, see also the fedora wiki.

Using xorg.conf

Xorg can also be configured via /etc/X11/xorg.conf or /etc/xorg.conf. You can also generate a skeleton for xorg.conf with:

# Xorg :0 -configure

This should create a xorg.conf.new file in /root/ that you can copy over to /etc/X11/xorg.conf.

Tip: If you are already running an X server, use a different display, for example Xorg :2 -configure.

Alternatively, your proprietary video card drivers may come with a tool to automatically configure Xorg: see the article of your video driver, NVIDIA or AMD Catalyst, for more details.

Note: Configuration file keywords are case insensitive, and "_" characters are ignored. Most strings (including Option names) are also case insensitive, and insensitive to white space and "_" characters.

Input devices

For input devices, the virtual package xf86-input-driver ensures at least one input driver of either xf86-input-evdev or xf86-input-libinput is installed.[2]

Udev, which is provided as a systemd dependency, will detect your hardware and both drivers will act as hotplugging input driver for almost all devices, as defined in the default configuration files 10-evdev.conf and 60-libinput.conf in the /usr/share/X11/xorg.conf.d/ directory.

After starting X server, the log file will show which driver hotplugged for the individual devices (note the most recent log file name may vary):

$ grep -e "Using input driver " ~/.local/share/xorg/Xorg.0.log

If both do not support a particular device, install the needed driver from the xorg-drivers group. The same applies, if you want to use another driver.

To influence hotplugging, see #Configuration.

For specific instructions, see also the libinput article, the following pages below, or the Fedora wiki entry for more examples.

Mouse acceleration

See Mouse acceleration.

Extra mouse buttons

See All Mouse Buttons Working.

Touchpad

See Synaptics or libinput.

Touchscreen

See Touchscreen.

Keyboard settings

See Keyboard configuration in Xorg.

Monitor settings

Getting started

Note: Newer versions of Xorg are auto-configuring, you should not need to use this.

First, create a new config file, such as /etc/X11/xorg.conf.d/10-monitor.conf.

/etc/X11/xorg.conf.d/10-monitor.conf
Section "Monitor"
    Identifier             "Monitor0"
EndSection

Section "Device"
    Identifier             "Device0"
    Driver                 "vesa" #Choose the driver used for this monitor
EndSection

Section "Screen"
    Identifier             "Screen0"  #Collapse Monitor and Device section to Screen section
    Device                 "Device0"
    Monitor                "Monitor0"
    DefaultDepth           16 #Choose the depth (16||24)
    SubSection             "Display"
        Depth              16
        Modes              "1024x768_75.00" #Choose the resolution
    EndSubSection
EndSection
Note: By default, Xorg needs to be able to detect a monitor and will not start otherwise. A workaround is to create a configuration file such as the example above and thus avoid auto-configuring. A common case where this is necessary is a headless system, which boots without a monitor and starts Xorg automatically, either from a virtual console at login, or from a display manager.

Multiple monitors

See main article Multihead for general information.

See also GPU-specific instructions:

More than one graphics card

You must define the correct driver to use and put the bus ID of your graphic cards.

Section "Device"
    Identifier             "Screen0"
    Driver                 "nouveau"
    BusID                  "PCI:0:12:0"
EndSection

Section "Device"
    Identifier             "Screen1"
    Driver                 "radeon"
    BusID                  "PCI:1:0:0"
EndSection

To get your bus ID:

$ lspci | grep VGA
01:00.0 VGA compatible controller: nVidia Corporation G96 [GeForce 9600M GT] (rev a1)

The bus ID here is 1:0:0.

Display size and DPI

Tango-inaccurate.pngThe factual accuracy of this article or section is disputed.Tango-inaccurate.png

Reason: Xorg always sets dpi to 96. See this, this and finally this. (Discuss in Talk:Xorg#)

The DPI of the X server is determined in the following manner:

  1. The -dpi command line option has highest priority.
  2. If this is not used, the DisplaySize setting in the X config file is used to derive the DPI, given the screen resolution.
  3. If no DisplaySize is given, the monitor size values from DDC are used to derive the DPI, given the screen resolution.
  4. If DDC does not specify a size, 75 DPI is used by default.

In order to get correct dots per inch (DPI) set, the display size must be recognized or set. Having the correct DPI is especially necessary where fine detail is required (like font rendering). Previously, manufacturers tried to create a standard for 96 DPI (a 10.3" diagonal monitor would be 800x600, a 13.2" monitor 1024x768). These days, screen DPIs vary and may not be equal horizontally and vertically. For example, a 19" widescreen LCD at 1440x900 may have a DPI of 89x87. To be able to set the DPI, the Xorg server attempts to auto-detect your monitor's physical screen size through the graphic card with DDC. When the Xorg server knows the physical screen size, it will be able to set the correct DPI depending on resolution size.

To see if your display size and DPI are detected/calculated correctly:

$ xdpyinfo | grep -B2 resolution

Check that the dimensions match your display size. If the Xorg server is not able to correctly calculate the screen size, it will default to 75x75 DPI and you will have to calculate it yourself.

If you have specifications on the physical size of the screen, they can be entered in the Xorg configuration file so that the proper DPI is calculated:

Section "Monitor"
    Identifier             "Monitor0"
    DisplaySize             286 179    # In millimeters
EndSection

If you only want to enter the specification of your monitor without creating a full xorg.conf create a new config file. For example (/etc/X11/xorg.conf.d/90-monitor.conf):

Section "Monitor"
    Identifier             "<default monitor>"
    DisplaySize            286 179    # In millimeters
EndSection

If you do not have specifications for physical screen width and height (most specifications these days only list by diagonal size), you can use the monitor's native resolution (or aspect ratio) and diagonal length to calculate the horizontal and vertical physical dimensions. Using the Pythagorean theorem on a 13.3" diagonal length screen with a 1280x800 native resolution (or 16:10 aspect ratio):

$ echo 'scale=5;sqrt(1280^2+800^2)' | bc  # 1509.43698

This will give the pixel diagonal length and with this value you can discover the physical horizontal and vertical lengths (and convert them to millimeters):

$ echo 'scale=5;(13.3/1509)*1280*25.4' | bc  # 286.43072
$ echo 'scale=5;(13.3/1509)*800*25.4'  | bc  # 179.01920
Note: This calculation works for monitors with square pixels; however, there is the seldom monitor that may compress aspect ratio (e.g 16:10 aspect resolution to a 16:9 monitor). If this is the case, you should measure your screen size manually.

Setting DPI manually

Note: While you can set any dpi you like and applications using Qt and GTK will scale accordingly, it's recommended to set it to 96, 120 (25% higher), 144 (50% higher), 168 (75% higher), 192 (100% higher) etc., to reduce scaling artifacts to GUI that use bitmaps. Reducing it below 96 dpi may not reduce size of graphical elements of GUI as typically the lowest dpi the icons are made for is 96.

For RandR compliant drivers (for example the open source ATI driver), you can set it by:

$ xrandr --dpi 144
Note: Applications that comply with the setting will not change immediately. You have to start them anew.

See Execute commands after X start to make it permanent.

Proprietary NVIDIA driver

DPI can be set manually if you only plan to use one resolution (DPI calculator):

Section "Monitor"
    Identifier             "Monitor0"
    Option                 "DPI" "96 x 96"
EndSection

You can manually set the DPI adding the options below on /etc/X11/xorg.conf.d/20-nvidia.conf (inside Device section):

Option              "UseEdidDpi" "False"
Option              "DPI" "96 x 96"

DPMS

DPMS (Display Power Management Signaling) is a technology that allows power saving behaviour of monitors when the computer is not in use. This will allow you to have your monitors automatically go into standby after a predefined period of time. See: DPMS

Composite

The Composite extension for X causes an entire sub-tree of the window hierarchy to be rendered to an off-screen buffer. Applications can then take the contents of that buffer and do whatever they like. The off-screen buffer can be automatically merged into the parent window or merged by external programs, called compositing managers. See the following article for more information: compositing window manager

Some window managers (e.g. Compiz, Enlightenment, KWin, Marco, Metacity, Muffin, Mutter, Xfwm) do compositing on their own. For other window managers, a standalone composite manager can be used.

List of composite managers

http://cairo-compmgr.tuxfamily.org/ || cairo-compmgr-gitAUR
  • Compton — Compositor (a fork of xcompmgr-dana)
https://github.com/chjj/compton || compton
  • Xcompmgr — Composite window-effects manager
http://cgit.freedesktop.org/xorg/app/xcompmgr/ || xcompmgr
  • Unagi — Modular compositing manager which aims written in C and based on XCB
http://projects.mini-dweeb.org/projects/unagi || unagiAUR

Tips and tricks

X startup tweaking (startx)

Tango-inaccurate.pngThe factual accuracy of this article or section is disputed.Tango-inaccurate.png

Reason: /usr/bin/startx should not be modified, startx recognises the options as command line arguments (Discuss in Talk:Xorg#)

For X's option reference see:

$ man Xserver

The following options have to be appended to the variable "defaultserverargs" in the /usr/bin/startx file:

  • Enable deferred glyph loading for 16 bit fonts:
-deferglyphs 16
Note: If you start X with kdm, the startx script does not seem to be executed. X options must be appended to the variable ServerArgsLocal in the /usr/share/config/kdm/kdmrc file.

Nested X session

Tango-view-fullscreen.pngThis article or section needs expansion.Tango-view-fullscreen.png

Reason: mention xephyr (Discuss in Talk:Xorg#)

To run a nested session of another desktop environment:

$ /usr/bin/Xnest :1 -geometry 1024x768+0+0 -ac -name Windowmaker & wmaker -display :1

This will launch a Window Maker session in a 1024 by 768 window within your current X session.

This needs the package xorg-server-xnest to be installed.

Starting GUI programs remotely

See main article: SSH#X11 forwarding.

On-demand disabling and enabling of input sources

With the help of xinput you can temporarily disable or enable input sources. This might be useful, for example, on systems that have more than one mouse, such as the ThinkPads and you would rather use just one to avoid unwanted mouse clicks.

Install the xorg-xinput package from the official repositories.

Find the name or ID of the device you want to disable:

$ xinput

For example in a Lenovo ThinkPad T500, the output looks like this:

$ xinput
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ TPPS/2 IBM TrackPoint                     id=11   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=10   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Sleep Button                              id=8    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=9    [slave  keyboard (3)]
    ↳ ThinkPad Extra Buttons                    id=12   [slave  keyboard (3)]

Disable the device with xinput --disable device, where device is the device ID or name of the device you want to disable. In this example we will disable the Synaptics Touchpad, with the ID 10:

$ xinput --disable 10

To re-enable the device, just issue the opposite command:

$ xinput --enable 10

Alternatively using the device name, the command to disable the touchpad would be:

$ xinput --disable "SynPS/2 Synaptics TouchPad"

Killing application with hotkey

Run script on hotkey:

#!/bin/bash
windowFocus=$(xdotool getwindowfocus);
pid=$(xprop -id $windowFocus | grep PID);
kill -9 $pid

Deps: xorg-xprop, xdotool

Troubleshooting

General

If a problem occurs, view the log stored in either /var/log/ or, for the rootless X default since v1.16, in ~/.local/share/xorg/. GDM users should check the systemd journal. [3]

The logfiles are of the form Xorg.n.log with n being the display number. For a single user machine with default configuration the applicable log is frequently Xorg.0.log, but otherwise it may vary. To make sure to pick the right file it may help to look at the timestamp of the X server session start and from which console it was started. For example:

$ grep -e Log -e tty Xorg.0.log
[    40.623] (==) Log file: "/home/archuser/.local/share/xorg/Xorg.0.log", Time: Thu Aug 28 12:36:44 2014
[    40.704] (--) controlling tty is VT number 1, auto-enabling KeepTty
  • In the logfile then be on the lookout for any lines beginning with (EE), which represent errors, and also (WW), which are warnings that could indicate other issues.
  • If there is an empty .xinitrc file in your $HOME, either delete or edit it in order for X to start properly. If you do not do this X will show a blank screen with what appears to be no errors in your Xorg.0.log. Simply deleting it will get it running with a default X environment.
  • If the screen goes black, you may still attempt to switch to a different virtual console (e.g. Ctrl+Alt+F2), and blindly log in as root. You can do this by typing root (press Enter after typing it) and entering the root password (again, press Enter after typing it).
You may also attempt to kill the X server with:
# pkill X
If this does not work, reboot blindly with:
# reboot

Black screen, No protocol specified.., Resource temporarily unavailable for all or some users

X creates configuration and temporary files in current user's home directory. Make sure there is free disk space available on the partition your home directory resides in. Unfortunately, X server does not provide any more obvious information about lack of disk space in this case.

CTRL right key does not work with oss keymap

Tango-inaccurate.pngThe factual accuracy of this article or section is disputed.Tango-inaccurate.png

Reason: The file will be overwritten on xkeyboard-config update; for such simple task should be used Xmodmap. (Discuss in Talk:Xorg#)

Edit as root /usr/share/X11/xkb/symbols/fr, and change the line:

include "level5(rctrl_switch)"

to

// include "level5(rctrl_switch)"

Then restart X, reboot or run

setxkbmap fr oss

DRI with Matrox cards stops working

If you use a Matrox card and DRI stops working after upgrading to Xorg, try adding the line:

Option "OldDmaInit" "On"

to the Device section that references the video card in xorg.conf.

Frame-buffer mode problems

If X fails to start with the following log messages,

(WW) Falling back to old probe method for fbdev
(II) Loading sub module "fbdevhw"
(II) LoadModule: "fbdevhw"
(II) Loading /usr/lib/xorg/modules/linux//libfbdevhw.so
(II) Module fbdevhw: vendor="X.Org Foundation"
       compiled for 1.6.1, module version=0.0.2
       ABI class: X.Org Video Driver, version 5.0
(II) FBDEV(1): using default device

Fatal server error:
Cannot run in framebuffer mode. Please specify busIDs for all framebuffer devices

Uninstall the xf86-video-fbdev package.

Launching multiple X sessions with proprietary NVIDIA on Xorg 1.16

When attempting to launch X sessions in multiple ttys on Xorg 1.16, you may be rejected with a log indicating that no drivers were found. I found that a workaround for this was to specifically tell X that we'd like to use the 'nvidia' driver.

/etc/X11/xorg.conf.d/20-nvidia.conf

Section "Device"
    Identifier "Device0"
    Driver     "nvidia"
    VendorName "NVIDIA Corporation"
    Option     "NoLogo" "True"
EndSection

Program requests "font '(null)'"

  • Error message: "unable to load font `(null)'."

Some programs only work with bitmap fonts. Two major packages with bitmap fonts are available, xorg-fonts-75dpi and xorg-fonts-100dpi. You do not need both; one should be enough. To find out which one would be better in your case, try this:

$ xdpyinfo | grep resolution

and use what is closer to the shown value.

Recovery: disabling Xorg before GUI login

If Xorg is set to boot up automatically and for some reason you need to prevent it from starting up before the login/display manager appears (if the system is wrongly configured and Xorg does not recognize your mouse or keyboard input, for instance), you can accomplish this task with two methods.

  • Change default target to rescue.target. See systemd#Change default target to boot into.
  • If you have not only a faulty system that makes Xorg unusable, but you have also set the GRUB menu wait time to zero, or cannot otherwise use GRUB to prevent Xorg from booting, you can use the Arch Linux live CD. Follow the installation guide about how to mount and chroot into the installed Arch Linux. Alternatively try to switch into another tty with Ctrl+Alt + function key (usually from F1 to F7 depending on which is not used by X), login as root and follow steps below.

Depending on setup, you will need to do one or more of these steps:

X clients started with "su" fail

If you are getting "Client is not authorized to connect to server", try adding the line:

session        optional        pam_xauth.so

to /etc/pam.d/su. pam_xauth will then properly set environment variables and handle xauth keys.

X failed to start: Keyboard initialization failed

If your hard disk is full, startx will fail. /var/log/Xorg.0.log will end with:

(EE) Error compiling keymap (server-0)
(EE) XKB: Could not compile keymap
(EE) XKB: Failed to load keymap. Loading default keymap instead.
(EE) Error compiling keymap (server-0)
(EE) XKB: Could not compile keymap
XKB: Failed to compile keymap
Keyboard initialization failed. This could be a missing or incorrect setup of xkeyboard-config.
Fatal server error:
Failed to activate core devices.
Please consult the The X.Org Foundation support at http://wiki.x.org
for help.
Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(II) AIGLX: Suspending AIGLX clients for VT switch

Make some free space on your root partition and X will start.

Rootless Xorg (v1.16)

As of version 1.16 [4], Xorg may run with standard user privileges with the help of logind. The requirements for this are:

  • systemd; version >=216 for multiple instances
  • Starting X via xinit; display managers are not supported
  • Kernel mode setting; implementations in proprietary display drivers fail auto-detection and require manually setting needs_root_rights = no in /etc/X11/Xwrapper.config.

If you do not fit these requirements, re-enable root rights in /etc/X11/Xwrapper.config:

needs_root_rights = yes

See also Xorg.wrap(1) and Systemd/User#Xorg as a systemd user service.

Broken redirection

While user Xorg logs are stored in ~/.local/share/xorg/Xorg.log, they do not include the output from the X session. To re-enable redirection, start X with the -keeptty flag:

exec startx -- -keeptty -nolisten tcp > ~/.xorg.log 2>&1

Or copy /etc/X11/xinit/xserverrc to ~/.xserverrc, and append -keeptty. See [5].

Why do I get a green screen whenever I try to watch a video?

Your color depth is set wrong. It may need to be 24 instead of 16, for example.

SocketCreateListener error

If X terminates with error message "SocketCreateListener() failed", you may need to delete socket files in /tmp/.X11-unix. This may happen if you have previously run Xorg as root (e.g. to generate an xorg.conf).