Multiseat une carte graphique debian buster - Seul seat0 présent

Bonjour,
Je viens vers vous car après avoir passé plusieurs jours à écumer le web à la recherche de solution, j’en suis toujours au même point.
Je cherche donc à mettre en place une solution multiseat sur une machine équipée d’une seule carte graphique intel, de deux écrans équipés chacun d’une dalle tactile qui seront en définitive les deux seuls moyen de saisie et accessoirement de deux claviers.
J’ai suivi cette page https://wiki.debian-fr.xyz/Multiposte_avec_une_carte_graphique en adaptant évidemment les fichiers de config et en plaçant les scripts non pas dans /etc/lightdm mais dans /etc/Xephyr. La reconstruction de Xephyr est très légèrement modifiée par rapport au wiki : les options de compilations sont dans un fichier rules.flags mais sinon pas de problème.

Lorsque je boot, je me retrouve avec les deux écrans noirs. Un ps -e|grep X me montre que les sessions Xephyr ne sont pas présentes.
Je vous mets les fichiers lightdm.conf, xorg.conf et les logs :

xorg.conf
Section "Monitor"
    Identifier   "eDP1"
    Option       "PreferredMode" "1024x768"
    Option       "DPMS" "true"
    Option       "Primary" "true"
EndSection

Section "Monitor"
    Identifier   "DP1"
    Option       "PreferredMode" "1024x768"
    Option       "Position" "1024 0"
    Option       "DPMS" "true"
EndSection

Section "Device"
    Identifier  "Card0"
    Driver      "intel"
    BusID       "PCI:0:2:0"
    Option      "Monitor-eDP1" "eDP1"
    Option      "Monitor-DP1" "DP1"
EndSection

Section "Screen"
    Identifier   "Screen0"
    Device       "Card0"
    Monitor      "eDP1"
    DefaultDepth 24
    SubSection "Display"
        Depth     24
        Virtual   2048 768
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier     "dualscreen"
    Screen       0 "Screen0"
EndSection
lightdm.conf
[LightDM]
greeter-user=root
user-authority-in-system-dir=false

[Seat:*]
xserver-allow-tcp=false
greeter-hide-users=false
user-session=lightdm-xsession
session-wrapper=/etc/X11/Xsession
session-setup-script=/etc/Xephyr/session-setup-script.sh -a 3 -v 7

[Seat:seat0]
xserver-layout=dualscreen
xserver-command=nohup X -br -dpms -s 0 -novtswitch -nocursor
greeter-session=fake-greeter

[Seat:seat-1]
xserver-command=/etc/Xephyr/Xephyr-command.sh -p 1 -t 1024x768 -P evdev -s /dev/input/by-id/usb-PixArt_USB_Optical_Mouse-event-mouse -c /dev/input/by-id/usb-Logitech_USB_Keyboard-event-kbd -d /dev/input/by-id/usb-Atmel_Atmel_maXTouch_Digitizer-event-if01
greeter-setup-script=/etc/Xephyr/Xephyr-greeter-setup.sh -p 1
greeter-session=lightdm-greeter

[Seat:seat-2]
xserver-command=/etc/Xephyr/Xephyr-command.sh -p 2 -t 1024x768 -P evdev -d /dev/input/by-id/usb-Focaltech_Systems_FT5926_MultiTouch-event-if01 -c /dev/input/by-id/usb-SEM_USB_Keyboard-event-kbd
greeter-setup-script=/etc/Xephyr/Xephyr-greeter-setup.sh -p 2 -d 1024,0
greeter-session=lightdm-greeter
Xorg.0.log
[    15.377] 
X.Org X Server 1.20.4
X Protocol Version 11, Revision 0
[    15.377] Build Operating System: Linux 4.19.0-9-amd64 x86_64 Debian
[    15.377] Current Operating System: Linux debian 4.19.0-9-amd64 #1 SMP Debian 4.19.118-2+deb10u1 (2020-06-07) x86_64
[    15.377] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.19.0-9-amd64 root=/dev/sda5 ro console=ttyS0 quiet
[    15.377] Build Date: 26 June 2020  07:51:00AM
[    15.377] xorg-server 2:1.20.4-1.1 (https://www.debian.org/support) 
[    15.377] Current version of pixman: 0.36.0
[    15.377] 	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
[    15.377] Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[    15.377] (==) Log file: "/var/log/Xorg.0.log", Time: Fri Jun 26 10:19:11 2020
[    15.378] (==) Using config file: "/etc/X11/xorg.conf"
[    15.378] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[    15.379] (++) ServerLayout "dualscreen"
[    15.379] (**) |-->Screen "Screen0" (0)
[    15.379] (**) |   |-->Monitor "eDP1"
[    15.380] (**) |   |-->Device "Card0"
[    15.380] (==) Automatically adding devices
[    15.380] (==) Automatically enabling devices
[    15.380] (==) Automatically adding GPU devices
[    15.380] (==) Max clients allowed: 256, resource mask: 0x1fffff
[    15.384] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[    15.384] 	Entry deleted from font path.
[    15.385] (==) FontPath set to:
	/usr/share/fonts/X11/misc,
	/usr/share/fonts/X11/100dpi/:unscaled,
	/usr/share/fonts/X11/75dpi/:unscaled,
	/usr/share/fonts/X11/Type1,
	/usr/share/fonts/X11/100dpi,
	/usr/share/fonts/X11/75dpi,
	built-ins
[    15.385] (==) ModulePath set to "/usr/lib/xorg/modules"
[    15.385] (II) The server relies on udev to provide the list of input devices.
	If no devices become available, reconfigure udev or disable AutoAddDevices.
[    15.385] (II) Loader magic: 0x55ea88bd9e20
[    15.385] (II) Module ABI versions:
[    15.385] 	X.Org ANSI C Emulation: 0.4
[    15.385] 	X.Org Video Driver: 24.0
[    15.385] 	X.Org XInput driver : 24.1
[    15.385] 	X.Org Server Extension : 10.0
[    15.387] (++) using VT number 7

[    15.387] (II) systemd-logind: logind integration requires -keeptty and -keeptty was not provided, disabling logind integration
[    15.388] (II) xfree86: Adding drm device (/dev/dri/card0)
[    15.399] (--) PCI:*(0@0:2:0) 8086:1902:8086:2212 rev 6, Mem @ 0xde000000/16777216, 0xc0000000/268435456, I/O @ 0x0000f000/64, BIOS @ 0x????????/131072
[    15.399] (II) LoadModule: "glx"
[    15.400] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[    15.412] (II) Module glx: vendor="X.Org Foundation"
[    15.412] 	compiled for 1.20.4, module version = 1.0.0
[    15.413] 	ABI class: X.Org Server Extension, version 10.0
[    15.413] (II) LoadModule: "intel"
[    15.413] (II) Loading /usr/lib/xorg/modules/drivers/intel_drv.so
[    15.417] (II) Module intel: vendor="X.Org Foundation"
[    15.417] 	compiled for 1.20.1, module version = 2.99.917
[    15.417] 	Module class: X.Org Video Driver
[    15.417] 	ABI class: X.Org Video Driver, version 24.0
[    15.417] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets:
	i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G,
	915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM,
	Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33,
	GM45, 4 Series, G45/G43, Q45/Q43, G41, B43
[    15.418] (II) intel: Driver for Intel(R) HD Graphics
[    15.418] (II) intel: Driver for Intel(R) Iris(TM) Graphics
[    15.418] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics
[    15.434] (II) intel(0): Using Kernel Mode Setting driver: i915, version 1.6.0 20180719
[    15.434] (II) intel(0): SNA compiled: xserver-xorg-video-intel 2:2.99.917+git20180925-2 (Andreas Boll <aboll@debian.org>)
[    15.434] (II) intel(0): SNA compiled for use with valgrind
[    15.455] (--) intel(0): Integrated Graphics Chipset: Intel(R) HD Graphics 510
[    15.455] (--) intel(0): CPU: x86-64, sse2, sse3, ssse3, sse4.1, sse4.2; using a maximum of 2 threads
[    15.455] (**) intel(0): Depth 24, (--) framebuffer bpp 32
[    15.455] (==) intel(0): RGB weight 888
[    15.455] (==) intel(0): Default visual is TrueColor
[    15.456] (II) intel(0): Output eDP1 using monitor section eDP1
[    15.456] (**) intel(0): Option "PreferredMode" "1024x768"
[    15.456] (**) intel(0): Option "Primary" "true"
[    15.457] (**) intel(0): Found backlight control interface intel_backlight (type 'raw') for output eDP1
[    15.457] (II) intel(0): Enabled output eDP1
[    15.457] (II) intel(0): Output HDMI1 has no monitor section
[    15.457] (II) intel(0): Enabled output HDMI1
[    15.457] (II) intel(0): Output DP1 using monitor section DP1
[    15.457] (**) intel(0): Option "PreferredMode" "1024x768"
[    15.457] (**) intel(0): Option "Position" "1024 0"
[    15.457] (II) intel(0): Enabled output DP1
[    15.457] (--) intel(0): Using a maximum size of 256x256 for hardware cursors
[    15.458] (II) intel(0): Output VIRTUAL1 has no monitor section
[    15.458] (II) intel(0): Enabled output VIRTUAL1
[    15.459] (II) intel(0): EDID for output eDP1
[    15.459] (II) intel(0): Manufacturer: CHR  Model: 7511  Serial#: 880
[    15.459] (II) intel(0): Year: 2014  Week: 5
[    15.459] (II) intel(0): EDID Version: 1.4
[    15.459] (II) intel(0): Digital Display Input
[    15.459] (II) intel(0): 8 bits per channel
[    15.459] (II) intel(0): Digital interface is DisplayPort
[    15.459] (II) intel(0): Max Image Size [cm]: horiz.: 43  vert.: 29
[    15.459] (II) intel(0): Gamma: 2.20
[    15.459] (II) intel(0): DPMS capabilities: StandBy Suspend Off
[    15.459] (II) intel(0): Supported color encodings: RGB 4:4:4 
...
[    16.331] (II) This device may have been added with another device file.
[    16.363] (**) SEM USB Keyboard Consumer Control: Applying InputClass "libinput keyboard catchall"
[    16.363] (II) Using input driver 'libinput' for 'SEM USB Keyboard Consumer Control'
[    16.363] (**) SEM USB Keyboard Consumer Control: always reports core events
[    16.363] (**) Option "Device" "/dev/input/event8"
[    16.363] (**) Option "_source" "_driver/libinput"
[    16.364] (II) libinput: SEM USB Keyboard Consumer Control: is a virtual subdevice
[    16.364] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3:1.1/0003:1A2C:0E24.0004/input/input8/event8"
[    16.364] (II) XINPUT: Adding extended input device "SEM USB Keyboard Consumer Control" (type: KEYBOARD, id 19)
[    16.364] (**) Option "xkb_model" "pc105"
[    16.364] (**) Option "xkb_layout" "fr"
[    16.364] (**) Option "xkb_variant" "latin9"
lightdm.log
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.26.0, UID=0 PID=825
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Monitoring logind for seats
[+0.00s] DEBUG: New seat added from logind: seat0
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:seat0
[+0.00s] DEBUG: Seat seat0: Starting
[+0.00s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.01s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.01s] DEBUG: Quitting Plymouth
[+0.01s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.03s] DEBUG: Using VT 7
[+0.03s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.03s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.03s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.03s] DEBUG: XServer 0: Launching X Server
[+0.04s] DEBUG: Launching process 834: /usr/bin/nohup X -br -dpms -s 0 -novtswitch -nocursor :0 -layout dualscreen -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.04s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.04s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.04s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.05s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.05s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.08s] DEBUG: posix_spawn avoided (automatic reaping requested) (fd close requested) 
[+1.07s] DEBUG: Got signal 10 from process 834
[+1.07s] DEBUG: XServer 0: Got signal from X server :0
[+1.07s] DEBUG: XServer 0: Connecting to XServer :0
[+1.07s] DEBUG: posix_spawn avoided (fd close requested) (child_setup specified) 
[+1.07s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+1.07s] DEBUG: Session pid=868: Started with service 'lightdm-greeter', username 'root'
[+1.09s] DEBUG: Session pid=868: Authentication complete with return value 0: Success
[+1.09s] DEBUG: Seat seat0: Session authenticated, running command
[+1.09s] DEBUG: Session pid=868: Running command /usr/bin/sleep infinity
[+1.09s] DEBUG: Creating shared data directory /var/lib/lightdm/data/root
[+1.09s] DEBUG: Session pid=868: Logging to /var/log/lightdm/seat0-greeter.log
[+1.15s] DEBUG: Activating VT 7
[+1.15s] DEBUG: Activating login1 session c2
[+1.15s] DEBUG: Seat seat0 changes active session to c2
[+1.15s] DEBUG: Session c2 is already active

Je ne maitrise pas trop tout ça donc s’il manque des informations, je suis dispo pour les ajouter.

Pourquoi les seats -1 & -2 ne sont pas présent ?

Pour info, j’ai essayé d’attacher les dalles tactiles, claviers et souris aux seat-1 & 2 à coup de loginctl attach mais sans plus de succès. Idem en passant par de règles udev.

Je crois que je n’ai rien oublié.
Merci de votre aide.

Pour information, je viens de refaire le même test en repassant en Stretch avec le même résultat. Se pourrait-il qu’il y ait un problème hardware ?

Et je me répond à nouveau. Je viens de voir qu’il faut nécessairement déclarer un device en master-of-seat dans les règles udev pour s’assurer de la présence du dit seat.

@Mimoza, ça serait vraiment sympa de mettre à jour la page pour cette information importante et éviter à d’autre débutant de galérer autant. D’un autre côté, c’est vrai que du coup, j’ai appris plein de trucs :wink:

Du coup, j’ai eu mes 2 sessions Xephyr, mais affichées sur le même écran. Après déplacement de l’une des deux à la main à coup de wmctrl, je me suis aperçu que l’une des deux sessions n’avais pas son greeter… Je continue mes investigations.

D’après lightdm.log, seat-1 semble lancer Xephyr avant le lancement de X… pas cool.

lightdm.log
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.18.3, UID=0 PID=536
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Registered seat module xlocal
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.01s] DEBUG: Monitoring logind for seats
[+0.01s] DEBUG: New seat added from logind: seat-1
[+0.01s] DEBUG: Seat seat-1: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat-1: Loading properties from config section Seat:seat-1
[+0.01s] DEBUG: Seat seat-1 has property CanMultiSession=no
[+0.01s] DEBUG: Seat seat-1: Starting
[+0.01s] DEBUG: Seat seat-1: Creating greeter session
[+0.01s] DEBUG: Seat seat-1: Creating display server of type x
[+0.01s] DEBUG: Seat seat-1: Starting local X display
[+0.01s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.01s] DEBUG: DisplayServer x-0: Launching X Server
[+0.01s] DEBUG: Launching process 544: /etc/Xephyr/Xephyr-command.sh -p 1 -t 1024x768  :0 -seat seat-1 -auth /var/run/lightdm/root/:0 -nolisten tcp
[+0.01s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.01s] DEBUG: New seat added from logind: seat0
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:seat0
[+0.01s] DEBUG: Seat seat0: Starting
[+0.01s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process "plymouth" (No such file or directory)
[+0.01s] DEBUG: Using VT 7
[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.01s] DEBUG: DisplayServer x-1: Logging to /var/log/lightdm/x-1.log
[+0.01s] DEBUG: DisplayServer x-1: Writing X server authority to /var/run/lightdm/root/:1
[+0.01s] DEBUG: DisplayServer x-1: Launching X Server
[+0.01s] DEBUG: Launching process 547: /usr/bin/nohup Xorg -br -dpms -s 0 -novtswitch -nocursor -seat seat0 :1 -seat seat0 -auth /var/run/lightdm/root/:1 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: DisplayServer x-1: Waiting for ready signal from X server :1
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat1
[+0.02s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.02s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.14s] DEBUG: Seat seat-2 added from logind
[+0.14s] DEBUG: New seat added from logind: seat-2
[+0.14s] DEBUG: Seat seat-2: Loading properties from config section Seat:*
[+0.14s] DEBUG: Seat seat-2: Loading properties from config section Seat:seat-2
[+0.14s] DEBUG: Seat seat-2 has property CanMultiSession=no
[+0.14s] DEBUG: Seat seat-2: Starting
[+0.14s] DEBUG: Seat seat-2: Creating greeter session
[+0.14s] DEBUG: Seat seat-2: Creating display server of type x
[+0.14s] DEBUG: Seat seat-2: Starting local X display
[+0.14s] DEBUG: DisplayServer x-2: Logging to /var/log/lightdm/x-2.log
[+0.14s] DEBUG: DisplayServer x-2: Writing X server authority to /var/run/lightdm/root/:2
[+0.14s] DEBUG: DisplayServer x-2: Launching X Server
[+0.14s] DEBUG: Launching process 560: /etc/Xephyr/Xephyr-command.sh -p 2 -t 1024x768  :2 -seat seat-2 -auth /var/run/lightdm/root/:2 -nolisten tcp
[+0.14s] DEBUG: DisplayServer x-2: Waiting for ready signal from X server :2
[+0.14s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat2
[+0.50s] DEBUG: Got signal 10 from process 547
[+0.50s] DEBUG: DisplayServer x-1: Got signal from X server :1
[+0.50s] DEBUG: DisplayServer x-1: Connecting to XServer :1
[+0.60s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.60s] DEBUG: Session pid=575: Started with service 'lightdm-greeter', username 'root'
[+0.61s] DEBUG: Session pid=575: Authentication complete with return value 0: Success
[+0.61s] DEBUG: Seat seat0: Session authenticated, running command
[+0.61s] DEBUG: Session pid=575: Running command /bin/sleep infinity
[+0.61s] DEBUG: Creating shared data directory /var/lib/lightdm/data/root
[+0.61s] DEBUG: Session pid=575: Logging to /var/log/lightdm/seat0-greeter.log
[+0.65s] DEBUG: Activating VT 7
[+0.65s] DEBUG: Activating login1 session c1
[+0.65s] DEBUG: Seat seat0 changes active session to c1
[+0.65s] DEBUG: Session c1 is already active
[+5.05s] DEBUG: Process 544 exited with return value 1
[+5.05s] DEBUG: DisplayServer x-0: X server stopped
[+5.05s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+5.05s] DEBUG: Seat seat-1: Display server stopped
[+5.05s] DEBUG: Seat seat-1: Stopping; greeter display server failed to start
[+5.05s] DEBUG: Seat seat-1: Stopping
[+5.05s] DEBUG: Seat seat-1: Stopping session
[+5.05s] DEBUG: Seat seat-1: Session stopped
[+5.05s] DEBUG: Seat seat-1: Stopped
[+5.05s] DEBUG: Seat seat-1: Stopping session
[+5.18s] DEBUG: Process 560 exited with return value 1
[+5.18s] DEBUG: DisplayServer x-2: X server stopped
[+5.18s] DEBUG: DisplayServer x-2: Removing X server authority /var/run/lightdm/root/:2
[+5.18s] DEBUG: Seat seat-2: Display server stopped
[+5.18s] DEBUG: Seat seat-2: Stopping; greeter display server failed to start
[+5.18s] DEBUG: Seat seat-2: Stopping
[+5.18s] DEBUG: Seat seat-2: Stopping session
[+5.18s] DEBUG: Seat seat-2: Session stopped
[+5.18s] DEBUG: Seat seat-2: Stopped
[+5.18s] DEBUG: Seat seat-2: Stopping session

Salut,
La méthode a une seule carte graphique étant plus galère je trouve, je l’ai abandonné pour la méthode à 2 CG, donc il est normal que la page ne soit pas à jour.
Le wiki est ouvert aux modifications, il te suffit de faire un compte :wink:

1 J'aime

OK. Dans ce cas, dès que tout fonctionne correctement, je m’y colle.

Et je continue mes investigations. Après quelques ajustement qu’il n’est pas nécessaire de décrire pour le moment, j’arrive enfin à avoir les deux sessions Xephyr sur leurs écrans avec les greeter affiché. Youpi ? Pas vraiment. En fait c’est un peu la loterie à chaque démarrage. Un coup les deux sessions sont sur le même écran, un coup seul un greeter est affiché (soit l’un, soit l’autre) et parfois écrans noirs.
En général cela se traduit dans le log de lightdm par un ordre de chargement des seats un peu aléatoire.

Alors pour infos, ce qui à débloqué la situation, c’est d’avoir déclaré dans les règles le GPU en master-of-seat :

ATTRS{idVendor}=="8086", ATTRS{idProduct}=="1902", ENV{ID_SEAT}="seat0", TAG+="master-of-seat"

D’autre part avec ou sans xorg.conf j’ai le même résultat. Du coup, pour le moment, je laisse Xorg se débrouiller.