Re: Real multi-user linux

Re: Real multi-user linux

[John Bradford]

> is it possible to use several logical terminals
> (tupels of monitor, keyboard and mouse) directly
> connected to _one_ system? I mean there is no problem
> to connect two keyboards, two mice and two graphic
> cards/monitors...
>
> But is there a possibility to group these to allow two
> users work simultanously on the same machine without
> having to go via serial console or network?
>
> I just can't imagine that no one has thougt about this
> before...

This idea has come up before, have a look at:

http://marc.theaimsgroup.com/?l=linux-kernel&m=101854006027152&w=2

http://marc.theaimsgroup.com/?l=linux-kernel&m=104353298205473&w=2

John.

Re: Real multi-user linux

[Terje Fåberg]

John Bradford <john@grabjohn.com> skrev:

> This idea has come up before, have a look at:
>  http://marc.theaimsgroup.com/?.....

Thank you for providing these references.  Especially
the first thread discusses some thoughts I had, too. 

To summarize: People have thought about of one linux
box directly supporting multiple (X-)consoles before.
But this is not possible as of now, because X would
have to be told to stop switching consoles and because
the kernel cannot activate more than one console at
one time. Additionately, multiple video cards may
require mappings into the same memory area for certain
functions. Some people have started to work on  a
solution, but these projects were orphaned. 

My motivation is simply a private one.  I have a
P3-866 with 1.5G RAM and a scsi raid here which serves
its own console and an old P133 as X terminal.
Although this machine is already some kind of
outdated, it has plenty of power to serve two users
with one KDE session each. 

I started to think about this, because the P133 died
away due to a failing processor fan. Although
replacing the whole machine with a similar one
probably is cheaper than a good usb keyboard and
mouse, it is also a question of comfort. No waiting
for the terminal to boot up, no double administration,
less power consumption, less space needed and so on. 

Although I have some C/C++ expirience, I have
absolutely no clues about kernel and or X internals,
so I guess I have to forget this for now. 

Regards, 
Terje


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Re: Real multi-user linux

[Gerhard Mack]

On Fri, 13 Jun 2003, Terje Fåberg wrote:
> John Bradford <john@grabjohn.com> skrev:
>
> > This idea has come up before, have a look at:
> >  http://marc.theaimsgroup.com/?.....
>
> Thank you for providing these references.  Especially
> the first thread discusses some thoughts I had, too.
>
> To summarize: People have thought about of one linux
> box directly supporting multiple (X-)consoles before.
> But this is not possible as of now, because X would
> have to be told to stop switching consoles and because
> the kernel cannot activate more than one console at
> one time. Additionately, multiple video cards may
> require mappings into the same memory area for certain
> functions. Some people have started to work on  a
> solution, but these projects were orphaned.
>
> My motivation is simply a private one.  I have a
> P3-866 with 1.5G RAM and a scsi raid here which serves
> its own console and an old P133 as X terminal.
> Although this machine is already some kind of
> outdated, it has plenty of power to serve two users
> with one KDE session each.
>
> I started to think about this, because the P133 died
> away due to a failing processor fan. Although
> replacing the whole machine with a similar one
> probably is cheaper than a good usb keyboard and
> mouse, it is also a question of comfort. No waiting
> for the terminal to boot up, no double administration,
> less power consumption, less space needed and so on.
>
> Although I have some C/C++ expirience, I have
> absolutely no clues about kernel and or X internals,
> so I guess I have to forget this for now.

You can gain most of those advantages by using the machine as a terminal
server.  http://neoware.com has solid state(fanless) clients.   So you
still get the lower admin costs and a nice quiet office.  Hopefully
someone else will reply with an even cheaper thin client.

	Gerhard



--
Gerhard Mack

gmack@innerfire.net

<>< As a computer I find your faith in technology amusing.

Re: Real multi-user linux

[Alan Cox]

On Gwe, 2003-06-13 at 16:19, Gerhard Mack wrote:
> You can gain most of those advantages by using the machine as a terminal
> server.  http://neoware.com has solid state(fanless) clients.   So you
> still get the lower admin costs and a nice quiet office.  Hopefully
> someone else will reply with an even cheaper thin client.

Cheapest off the shelf set up I know is a VIA EPIA and a cubid case with
the disk fan disabled since you have no disk. Also in the very small
category are the Lex-Lite (see http://www.linitx.co.uk)

Re: Real multi-user linux

[James Simmons]

> John Bradford <john@grabjohn.com> skrev:
> 
> > This idea has come up before, have a look at:
> >  http://marc.theaimsgroup.com/?.....
> 
> Thank you for providing these references.  Especially
> the first thread discusses some thoughts I had, too. 
> 
> To summarize: People have thought about of one linux
> box directly supporting multiple (X-)consoles before.
> But this is not possible as of now, because X would
> have to be told to stop switching consoles and because
> the kernel cannot activate more than one console at
> one time. Additionately, multiple video cards may
> require mappings into the same memory area for certain
> functions. Some people have started to work on  a
> solution, but these projects were orphaned. 

Not true. Your project has just finished it first stable 
release. Its just we are going commerical with this product.
We even have a modified distro to handle such a system. 
Yes you have to do special modifications to make 
multi-desktop systems work. 

> My motivation is simply a private one.  I have a
> P3-866 with 1.5G RAM and a scsi raid here which serves
> its own console and an old P133 as X terminal.
> Although this machine is already some kind of
> outdated, it has plenty of power to serve two users
> with one KDE session each. 
> 
> I started to think about this, because the P133 died
> away due to a failing processor fan. Although
> replacing the whole machine with a similar one
> probably is cheaper than a good usb keyboard and
> mouse, it is also a question of comfort. No waiting
> for the terminal to boot up, no double administration,
> less power consumption, less space needed and so on. 
> 
> Although I have some C/C++ expirience, I have
> absolutely no clues about kernel and or X internals,
> so I guess I have to forget this for now. 

   It has been done. I have a system at home running a 
multi-desktop system. I have a 2 user system and my 
partner in code developement, Aivil, has a 3 person
multi-desktop system working. 
   Now that we have a working product we can go to the 
next stage. Finding customers to sell it to. This weekend
I'm getting together with a few sales guys to discuss this.
   As for the potential of this. Its large. With Gnome/KDE
and OpenOffice running for 3,4 or more people at the same
time out of one box will be a enormous cost reducer for 
any business. You coudl even do Wine to run MS apps but I 
don't know what the legal ramifactions of that would be.
As a business we wouldn't do it out of fear of being sued.
    The next stage will be non PC boards supporting more than
one graphics display output. Every now and then you see such a
board. I seen a 8 graphics chip board with 8 video outputs. 
Embedded devices that open like a wallet with a display on each 
side. Multiuser game consoles would be really cool. Its going to 
be a fun future.
 

Re: Real multi-user linux

[Bernd Eckenfels]

In article <Pine.LNX.4.44.0306131713340.29353-100000@phoenix.infradead.org> you wrote:
>   As for the potential of this. Its large. With Gnome/KDE
> and OpenOffice running for 3,4 or more people at the same
> time out of one box will be a enormous cost reducer for 
> any business.

Just out of curiosity. How much is this reduction for hardware? How many do
you have to pay for a 3-place box compared to a 3-cheapthin-client+server
solution? Especially if you consider the cabling limitations?

Greetings
Bernd
-- 
eckes privat - http://www.eckes.org/
Project Freefire - http://www.freefire.org/

Re: Real multi-user linux

[Aivils.Stoss]

Hi, Terje
>is it possible to use several logical terminals
>(=tupels of monitor, keyboard and mouse) directly
>connected to _one_ system? I mean there is no problem
>to connect two keyboards, two mice and two graphic
>cards/monitors...
>
>But is there a possibility to group these to allow two
>users work simultanously on the same machine without
>having to go via serial console or network?

Yes.
You can read documentation un download paches from
http://startx.times.lv
or
http://www.schuldei.org/aivils

I have got working real multiple local X servers.
Main idea is from James Simmons.
/dev/tty1-63 is splited. Now we have a multiple
ranges of /dev/tty's
/dev/tty1-7 bounded with 1-st keyboard
/dev/tty8-16 bounded with 2-nd keyboard
and so on.
Also XFree86 server has a parameter vtXX , where
XX is a number of /dev/ttyXX. Now we can choose
right keyboard for right X sever.

Normal X server during initialization search all
video adapters and then disable these all and after
init enable one necessary video adapter. This feature
must be disabled. If You tell xf86 to use /proc
interface for PCI configuration, then is possible
filter xf86 PCI-steering commands with kernel.

In my case patching of XFree86 is not necessary.
Kernel do not allow disable innocent video adapters
and multiple XFree86 servers runs without interference.

Another trouble is with bunch of USB input devices.
After boot USB assing device files randomly - same
mouse may have a various /dev/input/mouseX device file,
because init 1-st 2-nd 3-rd . I use
/etc/hotplug/input.agent
This agent make symbolic links depends from mouse physicaly
location. So i do not use straight /dev/input/mouse0 but
input.agent created /dev/Amouse0 - symlink to right
mouse device file.

Another troble is with sound. Any programm under Linux
will use hers own sound interface. If You have multiple
sound cards, then any starting script must be patched.
Some programms are unconfigurable or i do not know how
to doe it (SUN java plugin for Netscape). My home users
well know this and configure popular apps (xmms) as they
like and create additional chaos.

Zero trobles with GLX hardware acceleration! This is true
for closed source Nvidia drivers :)

IMHO this solution is very usable for home computers with
restricted budget. I never do cost calculations, because i
will not 2-nd box in my home.

Aivils Stoss

Re: Real multi-user linux

[John Bradford]

> > So, instead of trying to add more and more terminals to a single box,
> > you could stick with four-headed X servers, which would probably be
> > more scalable.

> The biggest limitation is the PCI bus. Only so many cards can go in. I
> guess you could fill the machine up with graphics cards and go with
> external USB audio and TV tuner cards. One to match each graphics card.

No need:

A single machine can support four displays, keyboards, and mice easily.  We
can use such machines as X servers for four people.  Each one can be connected
via Ethernet to the Linux supercomputer.  That way you get the cost advantages
of the multi-headed setup, with the scalability of the X server setup.  I think
you could scale to 64 or 128 users like that.

John.

Re: Real multi-user linux

[James Simmons]

> > > So, instead of trying to add more and more terminals to a single box,
> > > you could stick with four-headed X servers, which would probably be
> > > more scalable.
> 
> > The biggest limitation is the PCI bus. Only so many cards can go in. I
> > guess you could fill the machine up with graphics cards and go with
> > external USB audio and TV tuner cards. One to match each graphics card.
> 
> No need:
> 
> A single machine can support four displays, keyboards, and mice easily.  We
> can use such machines as X servers for four people.  Each one can be connected
> via Ethernet to the Linux supercomputer.  That way you get the cost advantages
> of the multi-headed setup, with the scalability of the X server setup.  I think
> you could scale to 64 or 128 users like that.

  Basically you are describing a thin client kind of model. I like to 
create 
high end thin clients but I don't have any funding. Currently thin 
clients don't have the power to do multi-media as well as PCs. 
  I did everything so far with my own money and time. I don't think we 
need a supercomputer. Here is a idea but it would require a good amount 
of work. Create a X server that runs on one remote server and it programs 
the hardware remotely. Now that would save enormously. I started to work on 
this but didn't have time. Just some ideas to throw at you.

Re: Real multi-user linux

[John Bradford]

> > As the number of terminals increases you might want to investigate the
> > possibility of terminal driving units connected to the main box, like
> > this:

> Why. You can get 4 port S3 video cards for UKP 7 each on ebay now and
> then. That'll take you to more heads per box than you can sanely cable

Exactly - the sanely cable bit alone is a good reason to do it.

I've got an old mainframe terminal here that was used on a similar system,
(although obviously it's not in use here :-) ).

John.

Re: Real multi-user linux

[John Bradford]

> >     The next stage will be non PC boards supporting more than
> > one graphics display output. Every now and then you see such a
> > board. I seen a 8 graphics chip board with 8 video outputs.

> As the number of terminals increases you might want to investigate the
> possibility of terminal driving units connected to the main box, like
> this:

[snip diagram]

Of course, those terminal driving units could actually then just be
replaced with multiple-display-and-keyboard-enabled X servers.

So, instead of trying to add more and more terminals to a single box,
you could stick with four-headed X servers, which would probably be
more scalable.

John.

Re: Real multi-user linux

[James Simmons]

> > >     The next stage will be non PC boards supporting more than
> > > one graphics display output. Every now and then you see such a
> > > board. I seen a 8 graphics chip board with 8 video outputs.
> 
> > As the number of terminals increases you might want to investigate the
> > possibility of terminal driving units connected to the main box, like
> > this:
> 
> [snip diagram]
> 
> Of course, those terminal driving units could actually then just be
> replaced with multiple-display-and-keyboard-enabled X servers.
> 
> So, instead of trying to add more and more terminals to a single box,
> you could stick with four-headed X servers, which would probably be
> more scalable.

The biggest limitation is the PCI bus. Only so many cards can go in. I 
guess you could fill the machine up with graphics cards and go with 
external USB audio and TV tuner cards. One to match each graphics card.

Re: Real multi-user linux

[John Bradford]

>     The next stage will be non PC boards supporting more than
> one graphics display output. Every now and then you see such a
> board. I seen a 8 graphics chip board with 8 video outputs.

As the number of terminals increases you might want to investigate the
possibility of terminal driving units connected to the main box, like
this:

-----   -----   -----   -----   -----   -----
| T |   | T |   | T |   | T |   | T |   | T |   
-----   -----   -----   -----   -----   -----
  |______ | ______|       |______ | ______|
        | | |                   | | |
        -----                   -----
        | D |                   | D |
        -----                   -----
          |_______________________|
                      |
                    -----
                    | L |
                    -----

T=Terminal
D=Terminal driving unit
L=Linux box

John.

Re: Real multi-user linux

[Alan Cox]

On Gwe, 2003-06-13 at 18:34, John Bradford wrote:
> >     The next stage will be non PC boards supporting more than
> > one graphics display output. Every now and then you see such a
> > board. I seen a 8 graphics chip board with 8 video outputs.
> 
> As the number of terminals increases you might want to investigate the
> possibility of terminal driving units connected to the main box, like
> this:

Why. You can get 4 port S3 video cards for UKP 7 each on ebay now and
then. That'll take you to more heads per box than you can sanely cable

Re: Real multi-user linux

[James Simmons]

> > >     The next stage will be non PC boards supporting more than
> > > one graphics display output. Every now and then you see such a
> > > board. I seen a 8 graphics chip board with 8 video outputs.
> > 
> > As the number of terminals increases you might want to investigate the
> > possibility of terminal driving units connected to the main box, like
> > this:
> 
> Why. You can get 4 port S3 video cards for UKP 7 each on ebay now and
> then. That'll take you to more heads per box than you can sanely cable

Appian as well if you want high end video cards. S3 have been tested to 
see if they behave good with other cards. They are pretty good for this.

Real multi-user linux

[Terje Fåberg]

Hello, 

is it possible to use several logical terminals
(=tupels of monitor, keyboard and mouse) directly
connected to _one_ system? I mean there is no problem
to connect two keyboards, two mice and two graphic
cards/monitors...

But is there a possibility to group these to allow two
users work simultanously on the same machine without
having to go via serial console or network?

I just can't imagine that no one has thougt about this
before...

Regards, 
Terje

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Re: Real multi-user linux

[Bernd Eckenfels]

In article <20030612231942.78086.qmail@web12905.mail.yahoo.com> you wrote:
> is it possible to use several logical terminals
> (=tupels of monitor, keyboard and mouse) directly
> connected to _one_ system?

Yes sure.

> But is there a possibility to group these to allow two
> users work simultanously on the same machine without
> having to go via serial console or network?

the main problem is the hardware. It is most often easier to have a diskless
terminal connected via network, than to have a VGA cable to two workplaces.

Linux supports multiple XServers (on multiple cards or cards with multiple
ports), can you can configure them for multiple serial ports or usb ports
for the mouse. For the keyboard you can have one ps2 and multiple usb ports
(under x). I am not sure how the console handles multiple usb keyboards.

Greetings
Bernd
-- 
eckes privat - http://www.eckes.org/
Project Freefire - http://www.freefire.org/

Re: Real multi-user linux

[James Simmons]

> > is it possible to use several logical terminals
> > (=tupels of monitor, keyboard and mouse) directly
> > connected to _one_ system?
> 
> Yes sure.

Yes but it requires massive surgery to the kernel.

> > But is there a possibility to group these to allow two
> > users work simultanously on the same machine without
> > having to go via serial console or network?
> 
> the main problem is the hardware. It is most often easier to have a diskless
> terminal connected via network, than to have a VGA cable to two workplaces.
> 
> Linux supports multiple XServers (on multiple cards or cards with multiple
> ports), can you can configure them for multiple serial ports or usb ports
> for the mouse. For the keyboard you can have one ps2 and multiple usb ports
> (under x). I am not sure how the console handles multiple usb keyboards.

Its flaky. The XServers need some patches to make it behave correctly. We 
have working X servers that do this. Alot of configuring has to be done 
to. This also has been solved. We also had it working with multiple sound 
cards.
  BTW this is what the company I'm creating right now does. I just wanted 
to have a actually working product before I formed a company.

Re: Real multi-user linux

[Alan Cox]

On Gwe, 2003-06-13 at 18:00, James Simmons wrote:
>   BTW this is what the company I'm creating right now does. I just wanted 
> to have a actually working product before I formed a company.

Novel approach to business 8). You might want to have a chat with EMC UK
once you have stuff to sell. They were asking a lot about 2/4 users per
PC stuff when I met the boss a couple of years ago . I believe because
they do call centres (www.emcuk.com)