How to set up multiseat on Centos 7

[rjt69]

Wonder if you oughta change that WindowManger value mentioned earlier to Applications as that appears to be what Sun workstations do.

From https://wiki.gnome.org/Projects/Session ... omeSession
Once it has the final list of applications, the session manager starts them in 5 phases: Initialization, WindowManager, Panel, Desktop, and Applications.

"Initialization" is low-level stuff like gnome-settings-daemon, at-spi-registryd, that need to be running very early (before any windows are displayed)
Apps in this phase can make use of a D-Bus interface to set environment variables in gnome-session's environment. This can be used for things like $GTK_MODULES, $GNOME_KEYRING_SOCKET, etc
"WindowManager" includes window managers and compositing managers, and anything else that has to be running before any windows are mapped
"Panel" includes anything that permanently takes up screen real estate (via EWMH struts)
"Desktop" includes anything that draws on the desktop (eg, nautilus).
"Applications" is everything else


late night carnage ahead ... look in gdm's home folder for a /seat/ subfolder ....
ls -latr `cat /etc/passwd | grep gdm | cut -d: -f6`

[charlie101]

The desktop seems useless, but does ALT+F2 --> gnome-terminal work?
or gnome-session-properties to turn off autostarting apps.

Yes I can fire up a terminal.

Haven't tried gnome-session-properties .

Charlie101

[charlie101]

gdm and ConsoleKit log files should be spitting out something as well:
/var/log/gdm/

Code: Select all

(EE) 
(EE) Backtrace:
(EE) 0: /usr/bin/X (xorg_backtrace+0x55) [0x5917f5]
(EE) 1: /usr/bin/X (0x400000+0x195899) [0x595899]
(EE) 2: /lib64/libc.so.6 (0x7f4532390000+0x35a00) [0x7f45323c5a00]
(EE) 3: /usr/bin/X (mieqProcessDeviceEvent+0x125) [0x573375]
(EE) 4: /usr/bin/X (mieqProcessInputEvents+0xf7) [0x573537]
(EE) 5: /usr/bin/X (0x400000+0x618a0) [0x4618a0]
(EE) 6: /usr/bin/X (DisableDevice+0xb9) [0x430129]
(EE) 7: /usr/bin/X (0x400000+0x306c0) [0x4306c0]
(EE) 8: /usr/bin/X (0x400000+0x3c1d5) [0x43c1d5]
(EE) 9: /lib64/libc.so.6 (__libc_start_main+0xf5) [0x7f45323b1af5]
(EE) 10: /usr/bin/X (0x400000+0x26731) [0x426731]
(EE) 
(EE) Segmentation fault at address 0x118
(EE) Fatal server error:
(EE) Caught signal 11 (Segmentation fault). Server aborting
(EE) 
(EE) 
Please consult the The X.Org Foundation support  at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/var/log/Xorg.1.log" for additional information.
(EE) (II) AIGLX: Suspending AIGLX clients for VT switch
(EE) Server terminated with error (1). Closing log file.

/var/log/ConsoleKit/[/b][/tt]

No Colsolekit present. I assume this is s a systemd thing.


Charlie101

[charlie101]

Wonder if you oughta change that WindowManger value mentioned earlier to Applications as that appears to be what Sun workstations do.

When changed to 'Applications' I can login but have desktop only. Not panel, menu, taskbar or window manager.

late night carnage ahead ... look in gdm's home folder for a /seat/ subfolder ....
ls -latr `cat /etc/passwd | grep gdm | cut -d: -f6`

The only sub directories are:

Code: Select all

.  ..  .config  .ICEauthority  .local  .pulse

The complete file list is:

Code: Select all

./
./.pulse
./.pulse/default.pa
./.pulse/bf9aee4b5348480aae4afa06390b1197-device-volumes.tdb
./.pulse/bf9aee4b5348480aae4afa06390b1197-card-database.tdb
./.pulse/bf9aee4b5348480aae4afa06390b1197-default-sink
./.pulse/bf9aee4b5348480aae4afa06390b1197-default-source
./.ICEauthority
./.config
./.config/gnome-session
./.config/gnome-session/saved-session
./.config/pulse
./.config/pulse/cookie
./.config/dconf
./.config/dconf/user
./.config/ibus
./.config/ibus/bus
./.config/ibus/bus/bf9aee4b5348480aae4afa06390b1197-unix-0
./.config/ibus/bus/bf9aee4b5348480aae4afa06390b1197-unix-1
./.config/goa-1.0
./.local
./.local/share
./.local/share/sounds
./.local/share/gnome-shell
./.local/share/icc
./.local/share/icc/edid-589250a654ea92203590a8deee93f4df.icc
./.local/share/icc/edid-59bfe70cdba09e6f757329f940ff414b.icc
./.local/share/telepathy
./.local/share/telepathy/mission-control
./.local/share/telepathy/mission-control/accounts.cfg
./.local/share/telepathy/mission-control/accounts-goa.cfg
./.local/share/keyrings

charlie101

[charlie101]

QUESTION?

So does anyone know if gdm3 even works with multiseat?

Postings I've seen on the gnome.org say that gdm 2.2 upwards and early gdm 3 did not support multi-seat.
Apparently they were hoping to get it working by gdm 3.4. I emailed the developer list but haven't heard back yet.

I tried this same setup with Debian wheezy and it didn't work.
There clearly seemed to be issues around gdm, systemd, Xorg integration.
This seemed too big an issue for me to wait for and without the specific skills to help I moved on.

Ubuntu 14.10 worked pretty much out of the box. I simply had to setup some udev rules and that was it.
Interestingly though they use lightdm not gdm.

Charlie101

[rjt69]

i also "heard" gnome is not the WM to use for MultiSeat. Hopefully, RedHat steps up and makes it a priority as a sales rep said recently that Gome is their baby. Even Microsoft does a better job at MultiSeat even though it was in Unix over a decade ago.

[charlie101]

I can't spend forever on this and it appears to be a deep seated problem; probably related to the same gdm/systemd issues that Debian has.

I wanted to use this build for (Oracle) database training servers in a classroom, hence Centos.

It's crazy buying per seat hardware just to connect to the server (except for Plugable).

Now I'm going to have to go back to lightdm and Ubuntu even though it doesn't play with Oracle nearly as nicely as Centos.

Thanks for your help rjt69 and good luck with your efforts.

Charlie101

[TrevorH]

The nux-dextop repo has lightdm available for CentOS 7. Would that fix whatever issue you're having?

[charlie101]

Hi TrevorH

Thanks for your reply

The nux-dextop repo has lightdm available for CentOS 7. Would that fix whatever issue you're having?

I did look around for a way to install lightdm on Centos and couldn't find one. I obviously didn't look hard enough.
However, their webpage does say:

'These repos may or may not be up to date; use them at your OWN RISK#'

If I have to jump through too many non-tested, 'non-supported' hoops I tend to think why bother, isn't there a better way?
There are a number of hacks out there to get Debian working with multiseat but because they are not part of the official distribution you obviously could have all sorts of problems when it comes to updates etc.

As mentioned above I previously tested Ubuntu 14.10. I installed the server and then added Gnome to it. It worked well but used lightdm rather than gdm. I've now re-installed Ubuntu 14.10 but this time using the official Gnome flavour which is using gdm 3.10.0.1.

So whatever problems there might be with gdm/Xorg/systemd the Ubuntu 'multiseat team' seem to have solved them.
But then I guess 'multiseat team' says it all really.

Of course this is open source and the multiseat team web pages look like a useful resource for anyone seriously wanting to get this working on another distribution:

https://wiki.ubuntu.com/MultiseatTeam/Status, https://wiki.ubuntu.com/MultiseatTeam/Instructions


Charlie101