Monday, January 28, 2008

Coming soon: Multiseat in Ubuntu 8.04

In three months the guys of canonical are releasing the next Ubuntu version. As they did with the 6.06, the 8.04 is a LTS (Long Term Support) version. That ensures three years of support (updates, security fixes, etc), so these versions are ideal for sites intended to be working for a very long period of time with a minimal maintenance (i.e. no intentions to do major version upgrades but only keeping up to date the original version).



There are several changes that affect to the current multiseat configuration. The goal is just the same as it was in our fist multiseat configuration (using Ubuntu 6.06): To obtain two seats using just one graphic card with two video outputs.

The Ubuntu 8.04 release includes xorg 7.3 with some important changes compared to previous versions. The main advantage of that version is that the xserver-xephyr package includes support for evdev input events. We finally can obtain a full multiseat computer just doing some modifications in configuration files, and with no need of external patches. That eases the setup of the system as well as it avoids problems in the process of package updating.

Another relevant change is the use of xrandr instead of xinerama to manage the multiple outputs of a video card. At the begining that was a problem until we found a way to obtain the same as we did on the previous version: Showing a xephyr session on every screen.

We have been doing several tests with Ubuntu 8.04 alfa 2 and alfa 3. The result is a working prototype but we are still having some issues to fix. The fact of working with alfa and prerelease versions means to deal with additional problems, but we are confident in obtaining an easy to follow step by step tutorial to create a two seat computer when the final 8.04 version will be released.

10 comments:

serrs said...

Was there a reason you skipped over Gutsy? I've heard that GDM is broken?

Back 2-3 years ago I was doing backstreet ruby patches on Gentoo. That worked. It should be so much easier now. Maybe I should start testing 8.04, since I get keyboard/mouse lockup on gdm start with 7.10.

(I've done userful, inbetween times... it worked but I want 3d acceleration without the Xephyr nesting)

josean said...

We did several tests with Ubuntu 7.10, but without achieving the main goal: To avoid the need of installation of external patched files.

Ubuntu 7.10 includes xorg 7.2. The xserver-xephyr of that release had still not support of evdev input events. We had also additional problems due to the change from xinerama to xrandr.

Definitely, that version implied more problems and no advantages, so we did not publish an entry about it in the blog.

Ramesh said...

I am trying out multiterminal on Ubuntu 8.04 using xephyr. Some problems remain: 1. my mouse scroll wheel is not recognised
2. my multimedia keys are not recognised

My configuration i as below:

-keybd evdev,,device=/dev/input/event1,xkblayout=gb,xkbmodel=evdev
-mouse evdev,5,device=/dev/input/event2

If I use -keybd evdev,,device=/dev/input/event2
my multimedia keys work, but I get spurious 'q','w'and 'e' everytime I click any of the mouse buttons.

Anonymous said...

can you publish the testconfiguration

DeNNiS said...

i can't wait for this, keep up the good work!

i'm trying to setup a Four-Seater at this moment with Gutsy, hope it works.

serrs said...

Thanks for your additional info on (Gutsy) 7.10.

I have it almost working. My desire is two separate cards, as I believe Xephyr won't adequate OpenGL performance for my kids.

It (multiseat and GDM) works on Gentoo. But Ubuntu 7.10's seems to be a problem. I have no keyboard on either seat to login. If I "startx --" I can use the keyboard just fine.

I may post how I mangle GDM. Too bad 8.04 is not 8.02 :)

Anonymous said...

I just want to say, thanks for your site. I've tried Setting up the multiseat using 6.06, but it's failing miserably. I'm gong to wait for 8.04, which will hopefully add the support so I dont have to mess areound with patches, etc.

Thanks for your site, I will be checking it when 8.04 comes out for a guide, and hopefully more succes.

Motin said...

I wrote an HOWTO on achieving multiseat on-the-fly (no change of configuration files and no restart of X) using Gutsy - I believe it works with Hardy as well: http://ubuntuforums.org/showthread.php?t=707796

Anonymous said...

Am preparing to build a multiseat system to support 10 users using dual head vga cards(preferably ATI),am looking for a script to automate the said setup, i would really appreciate if someone has one ready and is will to share.

Thanks.

Anders said...

MDM / Multi Seat Display Manager / Multiseat Display Manager is available: http://www.phoronix.com/scan.php?page=news_item&px=NjczMg

This is a HUGE step forward!

.deb Packages for Hardy available here! http://wiki.c3sl.ufpr.br/multiseat/index.php/Installing

See also http://brainstorm.ubuntu.com/idea/3442/