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We have a small student computer lab at the university (50 users, under 10
people in lab at any time). We do need Windows systems for specific
software, but since we are engineering students there are many lab users
comfortable with UNIX (console or X). We are poor and have crappy hardware.
There is one "very powerful" x86 machine, two medium powered machines, and
many slow machines (Pentium 100 ish, little RAM).

Years ago, we had a purely NT/2000 lab but this was a disaster (server
security problem). Since then I installed a Linux-based firewall and NAT
gateway, and set up our very powerful machine running Slackware and Samba
as a NT primary domain controller (PDC). This Linux host has all the user
accounts and home directories on it. Also provides printer access.

The other Windows hosts can login using the Linux/Samba server and access
their files in their $HOME directories. This works flawlessly except for
some minor roaming profile problems I hope are corrected in Samba 3.x.

The problem is - while this setup works, it is an inefficient use of our
resources since our only very powerful machine is the dedicated Linux
server. With the remaining slow machines there is no way to have usable
Windows hosts [ NT4 sucks, tried it ]. But these slow machines are numerous
and have network capabilities, so I would really like to use them as dumb
terminals to full blown X (GNOME) environments on the Slackware server!

So my question is, what is the best way to set up these slow machines
(which have SVGA monitors) as fully graphical login terminals to the Linux
Slackware server running X.org? Ideally we want no data stored on those
dumb terminals -- I'm even hoping they can just boot off CD-ROMs. So users
would log in and see their own GNOME desktops on the Linux server, and run
all the applications remotely. If I can pull this off then those slow
machines will be convenient to use, fast graphical workstations!

--
Jem Berkes
http://www.sysdesign.ca/

Jem Berkes wrote:
> We have a small student computer lab at the university (50 users, under 10
> people in lab at any time). We do need Windows systems for specific
> software, but since we are engineering students there are many lab users
> comfortable with UNIX (console or X). We are poor and have crappy hardware.
> There is one "very powerful" x86 machine, two medium powered machines, and
> many slow machines (Pentium 100 ish, little RAM).
>
> Years ago, we had a purely NT/2000 lab but this was a disaster (server
> security problem). Since then I installed a Linux-based firewall and NAT
> gateway, and set up our very powerful machine running Slackware and Samba
> as a NT primary domain controller (PDC). This Linux host has all the user
> accounts and home directories on it. Also provides printer access.
>
> The other Windows hosts can login using the Linux/Samba server and access
> their files in their $HOME directories. This works flawlessly except for
> some minor roaming profile problems I hope are corrected in Samba 3.x.
>
> The problem is - while this setup works, it is an inefficient use of our
> resources since our only very powerful machine is the dedicated Linux
> server. With the remaining slow machines there is no way to have usable
> Windows hosts [ NT4 sucks, tried it ]. But these slow machines are numerous
> and have network capabilities, so I would really like to use them as dumb
> terminals to full blown X (GNOME) environments on the Slackware server!
>
> So my question is, what is the best way to set up these slow machines
> (which have SVGA monitors) as fully graphical login terminals to the Linux
> Slackware server running X.org? Ideally we want no data stored on those
> dumb terminals -- I'm even hoping they can just boot off CD-ROMs. So users
> would log in and see their own GNOME desktops on the Linux server, and run
> all the applications remotely. If I can pull this off then those slow
> machines will be convenient to use, fast graphical workstations!
>

It's very do-able.
Read up a bit on XDMCP

This should get you started...

http://www.tldp.org/HOWTO/XDMCP-HOWTO/

--
Tom Wilson
What the large print giveth, the small print taketh away.

Tom Wilson wrote:

>> So my question is, what is the best way to set up these slow machines
>> (which have SVGA monitors) as fully graphical login terminals to the
>> Linux Slackware server running X.org?

>
> It's very do-able.
> Read up a bit on XDMCP

You might also give this a gander:

http://www.linuxgazette.com/issue27/kaszeta.html

"This page describes how to convert low-end 386/486 PC's into standalone
X Window Systems terminals which can serve as graphical terminals to
your existing Linux/Unix workstations."

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In alt.os.linux.slackware, Jem Berkes dared to utter,
> So my question is, what is the best way to set up these slow machines
> (which have SVGA monitors) as fully graphical login terminals to the Linux
> Slackware server running X.org?

What you're trying to do has been done by people much better than
anyone here at doing that. It's called the Linux Terminal Server
Project and I can vouche that it's good stuff so long as you don't
require any apps that must run in Windows.

http://ltsp.org/

- --
It is better to hear the rebuke of the wise,
Than for a man to hear the song of fools.
Ecclesiastes 7:5
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"Jem Berkes" <jb@users.pc9.org> wrote in message
news:Xns954ED331E48A8jbuserspc9org@205.200.16.73.. .

> So my question is, what is the best way to set up these slow machines
> (which have SVGA monitors) as fully graphical login terminals to the Linux
> Slackware server running X.org? Ideally we want no data stored on those
> dumb terminals -- I'm even hoping they can just boot off CD-ROMs. So users
> would log in and see their own GNOME desktops on the Linux server, and run
> all the applications remotely. If I can pull this off then those slow
> machines will be convenient to use, fast graphical workstations!

Define "slow machines". A 500 MHz machine is plenty to run a decent Linux
X-server and network clients for LDAP, SMB, NFS, email, and other basic
protocols, and can do comfortable local compilation. A 500 MHZ machine
running Windows is fairly burdened, especially by Win2000 and even moreso by
WinXP.

I don't recomment running Windows on less than 1 GHz these days, but happily
hand people 500 MHz Linux boxes as local compilation and work machines and
expect them to get work done.

Nico Kadel-Garcia wrote:

> Define "slow machines". A 500 MHz machine is plenty to run a decent
> Linux X-server and network clients for LDAP, SMB, NFS, email,

Only problem is that the computers in question were described as Pentium
100 ish, making a lot slower than a 500 MHz computer.

In comp.os.linux.setup Jem Berkes <jb@users.pc9.org> wrote:
> So my question is, what is the best way to set up these slow machines
> (which have SVGA monitors) as fully graphical login terminals to the Linux
> Slackware server running X.org? Ideally we want no data stored on those

No - the P100s are quite capable of running the X serverm and should do
so. Yes, you may wish to run the window managers on the main server
instead of on the P100s, but I'd hope to run them on the P100s too.
Experiment.

> dumb terminals -- I'm even hoping they can just boot off CD-ROMs. So users

There's no point. They have disks of at least 1.2GB, no? That's miles
better than a cdrom. And if you were determined to go diskless (why?
What's wrong with local swap?) you'd boot them via bootp on a remote
nfs root from a remote kernel, thus avoiding a cdrom.

> would log in and see their own GNOME desktops on the Linux server, and run
> all the applications remotely.

Yes, this was my main point - sure, the apps should be run on the
server, which implies login to the server from the xdm screen, which
really implies that xdm is running on the server and controlling
a remote display. But you don't have to have it that way - you can run
xdm on the clients and arrange that all the logins include a
passwordless (rsa -authenticated) ssh login to the server in their
GiveConsole sequence. That's what I'd do.

> If I can pull this off then those slow
> machines will be convenient to use, fast graphical workstations!

Check oit th Linux Terminal Server Project pages on the web.

Peter

> No - the P100s are quite capable of running the X serverm and should
> do so. Yes, you may wish to run the window managers on the main
> server instead of on the P100s, but I'd hope to run them on the P100s
> too. Experiment.

I have definitely tried it. These machines have around 16 MBytes of RAM and
the disks (if there are one) are about 1 gigabyte. Everything is awfully
slow to load off the disk. Performance is awful!

> There's no point. They have disks of at least 1.2GB, no?

No And we have too few hard drives any way.

> And if you were determined to go diskless (why?
> What's wrong with local swap?) you'd boot them via bootp on a remote
> nfs root from a remote kernel, thus avoiding a cdrom.

I'm not absolutely bent on it, but going diskless is good because we have
very few hard drives. Booting up using an nfs root sounds like a good idea,
actually!

> Yes, this was my main point - sure, the apps should be run on the
> server, which implies login to the server from the xdm screen, which
> really implies that xdm is running on the server and controlling
> a remote display. But you don't have to have it that way - you can run
> xdm on the clients and arrange that all the logins include a
> passwordless (rsa -authenticated) ssh login to the server in their
> GiveConsole sequence. That's what I'd do.

I tried a quick test using XDMCP (GDM on the server) and the results from
the 'slow machine' using Knoppix to access xdm was very encouraging!

--
Jem Berkes
http://www.sysdesign.ca/

>> So my question is, what is the best way to set up these slow machines
>> (which have SVGA monitors) as fully graphical login terminals to the
>> Linux Slackware server running X.org? Ideally we want no data stored
>> on those dumb terminals -- I'm even hoping they can just boot off
>> CD-ROMs. So users would log in and see their own GNOME desktops on
>> the Linux server, and run all the applications remotely. If I can
>> pull this off then those slow machines will be convenient to use,
>> fast graphical workstations!
>>
>
> It's very do-able.
> Read up a bit on XDMCP
>
> This should get you started...
>
> http://www.tldp.org/HOWTO/XDMCP-HOWTO/

Thanks for this tip, also for Linux Terminal Server Project pointer.

I decided to try the XDMCP tonight because it seemed simpler. I was
pleasantly surprised! On the server running Slackware 10, this is all I
had to do (documented here for anyone else who wants to try it).

1. Edit /etc/inittab to make default runlevel 4 (X display manager)
Declare display manager in rc.4

2. Assuming GDM, edit /etc/X11/gdm/gdm.conf and under [xdmcp]
Enable = true

3. Edit /etc/rc.d/rc.local to enable the X font server
/usr/X11R6/bin/xfs -daemon -droppriv

4. Edit /usr/X11R6/lib/X11/fs/config and define font paths in
catalogue = (list of FontPath's from xorg.conf, step 5)

5. Edit /etc/X11/xorg.conf and remove the FontPath entries that went to
xfs's catalogue (step 4). Instead only have
FontPath "tcp/localhost:7100"

6. Start the xfs as per step 3, verify with
fslsfonts -server "tcp/localhost:7100"

Surprisingly simple. I used a knoppix CD to boot to a console and ran
X -query 192.168.0.50

That was it, display manager came up beautifully. Everything (login
prompt, desktop session, exit) worked exactly as if I was local.
Fantastic!

--
Jem Berkes
http://www.sysdesign.ca/

In comp.os.linux.setup Jem Berkes <jb@users.pc9.org> wrote:
> > No - the P100s are quite capable of running the X serverm and should
> > do so. Yes, you may wish to run the window managers on the main
> > server instead of on the P100s, but I'd hope to run them on the P100s
> > too. Experiment.
>
> I have definitely tried it. These machines have around 16 MBytes of RAM and

The ram is the killer - I run a P100 with X and kde under debian quite
happily, but it has 48MB ram. I use another P100 as the departmental
incoming mail hub and name server, and another as the main web server,
but these have considerable (96MB) of ram.

> the disks (if there are one) are about 1 gigabyte. Everything is awfully
> slow to load off the disk. Performance is awful!
>
> > There's no point. They have disks of at least 1.2GB, no?
>
> No And we have too few hard drives any way.

Well, if it is ~ 1GB, I would have expected it to be 1.2GB, from the
platter size in use then.

> I tried a quick test using XDMCP (GDM on the server) and the results from
> the 'slow machine' using Knoppix to access xdm was very encouraging!

Good!

Peter