multi head setup

phrakture · 2005-08-09 22:48:50

I've always been curious about this, but have yet to try it...

X has the potential to run multiple screens at the same time (display :0.0, :0.1, :0.2, etc), so I wonder, with a proper X server setup, would it be feasable to have a multi-user beast running off one box?

i.e. a whole mess of usb hubs for kbd/mice, and a bunch of PCI video cards with multiple outputs.

It'd be an interesting setup, to say the least, and would be fun for things like internet cafes and libraries, et al. The problem would be keeping stray processes from killing other's sessions, as well as system resources. However, if you set them all up as thin clients, I could see if being really useful.

Anyway, I'm looking for success stories or something... anyone?

lillwad · 2005-08-10 00:15:47

I vaguely remember reading a thread about somebody trying this, but can't remember what forum it was on. Sorry . Google came up with these guys though:

http://opensensesolutions.com/faq.html

Kern · 2005-08-10 07:47:04

Phrakture,
maybe checkout here

linked from this Archforum thread

phrakture · 2005-08-10 15:09:07

Naw, that's not what I was getting at - I know pretty much *how* to do it, assuming I had the time and extra monitors, but I'm just looking to see if anyone actually has done it... I'd like to hear some stories or something 8)

mommy, tell me a story 8)

rhfrommn · 2005-08-10 20:18:13

Check out Sun's thin client solution - the SunRay.

We use those where I work. We have one small (2x proc, 8gb ram) server supporting 30 or so clients. Each of them is its own X display just like you said. You have to figure out which screen you are on and set your DISPLAY variable appropriately to get any gui apps you run to display properly.

They are incredibly slick. And the administration is great. "Your sunray quit working? Throw it in the trash, the replacement will be in the interoffice mail tomorrow." At $300 each it is cheaper to buy a bunch of spares than worry about desktop support. And the server is extremely low maintenance once you have the initial config done.

zezaz · 2005-08-11 11:50:35

Hi phrakture,

I actually tested it (unsuccessfully) 2 years ago on a Debian Woody. I only had 1 PC at that time and i wanted to try to provide dual access to it to my wife and me. And, having used a multi-terminal platform (VT100 powered ) as student, i thought it was quite fun to give it a try!

Since i had no dualhead video card, i used 2 video cards:

- Terminal 1: PS/2 Keyboard + PS/2 Mouse + Geforce 2 MX (AGP) + 15'' screen (color)
- Terminal 2: USB Keyboard + USB Mouse + S3 Virge (PCI) + 14'' screen (mono)

Writing a correct XF86Config file was not difficult. The problems i had were with the hardware and the kernel.

First, from what i remember, i had to find a PCI card as secondary card. I don't remember precisely why, maybe it was simply by conception of the PC architecture, but you could not manage to have 2 AGP cards working at the same time.

But the main problem was to have this work on Linux. From what i understood, the terminal layer of the 2.4 kernel locked resources in such a way that could not let XFree handle more than one real terminal at the same time. In other words: one screen worked, the other did not.

The patches from http://cambuca.ldhs.cetuc.puc-rio.br/multiuser/ did not help me (the XFree version of Debian was quite different from upstream, with already many patches). From what i know the 2.5.x kernel series saw a refactoring of the terminal layer, but it happened much after i had given up.

At first i had thought that such a setup would work naturally thanks to X design, but in fact i spent much time to end up on blocking, low-level, not-so-well-documented OS problems.

The good news for me is that now i have 2 PCs at home, so i have no need to try this anymore

If you try it on your side - and manage to build a working setup, i am sure that many will be interested though!. Personnally i would be very interested to know if it works on other OSes too (esp. BSDs).

zezaz · 2005-09-03 08:45:10

Hi phrakture,

If you still want to give it a try, here is an interesting article called "The State of Linux Graphics" :

http://www.freedesktop.org/~jonsmirl/graphics.html

Of particular interest are the paragraph "Making multiuser work" and followings.

Arch Linux

#1 2005-08-09 22:48:50

multi head setup

#2 2005-08-10 00:15:47

Re: multi head setup

#3 2005-08-10 07:47:04

Re: multi head setup

#4 2005-08-10 15:09:07

Re: multi head setup

#5 2005-08-10 20:18:13

Re: multi head setup

#6 2005-08-11 11:50:35

Re: multi head setup

#7 2005-09-03 08:45:10

Re: multi head setup

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