Remote X-Windows

[mcdougrs]

Ok I was just sitting here trying to figure out a way I could get by with a second machine and only one monitor(without buying a KVM switch)...

Then it hit me I saw it in one of my classes I took in college, unfortunately I wasn't paying attention that day :'( I remember them forwarding X-Windows to another computer... so I could use, oh, KDE for an example via an X interpreter for windows. Am I making any sense here or am I jsut mumbling please let me know if this at least makes sense to someone.

Thanx

[civ1492]

hmm exporting X isnt very hard to do just ssh into the box where from where you want to get your X exported and do

export DISPLAY="192.168.1.1:0.0"

replace the 192.168.1.1 address with the pc from where you want to get X exported and then you can start any programm you want kwrite for example in the shell

kwrite &

now your kwrite gets exported to the other machine ..

[mcdougrs]

So if you ssh in then it is already using ssh right... Cuz for some reason I thought that there was something else you had to do to get it to use ssh.

Ok lets say for the sake of argument I have a 4 machines and 3 monitors... if I log onto to the box with the same user.. will it be able to tell the different sessions apart and be able to export the screen to each session?

[civ1492]

the display gets exported over the ssh connection - so it is already using ssh ..

hmm dont know what you mean .. if you are logged in with user1 via ssh and then export the screen, it is user1 who is using the applications cause you exported it for user1 - but you couldn't really tell if you are now running one texteditor as user1 or as user2 - except from the ssh session where you would see that this user has started that editor ..

[Compunuts]

[quote author=mcdougrs link=board=23;threadid=4515;start=0#45136 date=1028903672]
So if you ssh in then it is already using ssh right... Cuz for some reason I thought that there was something else you had to do to get it to use ssh.[/quote]
I'm not sure what you mean either. For you to be able to use SSH, you need OpenSSH server. You can download it from openbsd.org site.

For you to be able to view X sessions remotely, you need X servers. For Linux boxes with X server installed, there is no problem. But you need both KDE and GNOME if you want to display both X sections.

So lets say that you have one box with KDE. Another box with GNOME. But you want to view both boxes on the third machine, you need both KDE and GNOME installed on the third box, I THINK. ( I have never tried with one DE since I installed both anyway on all of my boxes ).

if I log onto to the box with the same user.. will it be able to tell the different sessions apart and be able to export the screen to each session?

It's just like SSH sessions. EACH session you log in will be of different. So if you log in three times, it will be three sessions. You will NOT be able to view the same section on three different boxes as well as you can't view the old session on one box at another box.

[quote author=Compunuts link=board=23;threadid=4515;start=0#45226 date=1028946221]
But you need both KDE and GNOME if you want to display both X sections.
[/quote]

really? i've never tried it actually but if ssh just exports the actual display, wouldn't it use all the libraries (for KDE or Gnome apps) on the machine where the application is actually running?

i always thought that if ur using X sessions over ssh that it would only export the graphical part.. the actual display of the window and that everything the application needs to run would be used on the box that is exporting the display. what's the point of running X remotely if the client pc still needs all the required libraries? cuz if it needs the libraries, it means it will use them, which means CPU usage and i always thought that running X remotely was a great way to let old boxes still be able to run X apps at the speed of which the server can process them

[Compunuts]

[quote author=Ralinx link=board=23;threadid=4515;start=0#45272 date=1028982932]
really? i've never tried it actually but if ssh just exports the actual display, wouldn't it use all the libraries (for KDE or Gnome apps) on the machine where the application is actually running? [/quote]
Yeap. You still need X packages even on Windows box if you want to display your Linux box's X session on Windows box. That software is NOT FREE.

i always thought that if ur using X sessions over ssh that it would only export the graphical part.. the actual display of the window and that everything the application needs to run would be used on the box that is exporting the display. what's the point of running X remotely if the client pc still needs all the required libraries?

It export required information to be able to display. BUT if you are to export ALL the required data including X Windowing libraries, the data needed to transfer would be so huge that it will be almost impossible to view the desktop remotely.

cuz if it needs the libraries, it means it will use them, which means CPU usage and i always thought that running X remotely was a great way to let old boxes still be able to run X apps at the speed of which the server can process them

Yeap. It's. Let's say you are running drawing application. Your drawing application still use the processing power of host machine but it will just be using the display part of it from the client machine. The host computer still process the application data with its higher CPU speed but your client is just processing the display part of it.
When we've done some school labs, what we do is we have one Quad P III Xeon machine as host box and some P 133 to P 166 boxes have minimal setup with X-windowing. That's where my appreciation for Debian comes in. ;D

[jbstew32]

wow i've never thought about doin that! Cool!

[Schotty]

It seems there may be some cunfusion as to how and what is going on.

Server has X, and is to export to a Client.

Client talks Server, and can start GDM to get a login via ssh (optimally).

Any app that is run on there, is actually being executed by Server, not the client.

There are a few ways to do remote X, but the simplest and more seecure way is via ssh. For a bit I was playing with this, and had tty7 for my local X server, and tty8 as my remote X session. It worked okay. A bit slow, bit that is due moreso to my LAN setup than anything else. I had the remote X server going thru my crummy switch, which has a habit of making all connections REALLY latent when also using my hub. In the end all I needed to do was remove the hub from the setup, and the switch was fast.... but I digress...

In what I saw here, once whoever it was setup the export variable correctly, the remote host can launch XDM and start doing all processing under the remote X session, not locally. It would be over ssh. In the SSH session, you could do a

mozilla &

and mozilla would load up. If you had setup it to pop up xterms, you could do the same thing in there, Dont believe me? Use the remote X session's xterm and do a

touch myweener

and that file would only be in the user's dir on the X server.

[Pleiades]

This isn't exactly what you're talking about (it's not done over ssh), but I'm looking into this at the moment, to breath some life into my wifes P233. Works a treat.

http://www.tldp.org/HOWTO/mini/XDM-Xterm/