X forwarding via ssh - relocating a still running program?

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Negated Void · Post by **Negated Void** » Sat Mar 04, 2006 6:33 pm

Hello!
I'm new to using linux in a true unix network, so things like X forwarding over ssh are looking awesome to me (actually, just got that setup, and i love it to death). Is it possible for me to have a program running on my desktop (letsay... my copy of gaim) and then somehow pull it onto another computer (instead of just openening a new instance of gaim)?

Thanks in advance,
--Murph

pyxel · Post by **pyxel** » Sat Mar 04, 2006 6:50 pm

I'm interessed too.
Gaim running in screen on server, look good :p

widremann · Post by **widremann** » Sat Mar 04, 2006 7:01 pm

Use VNC to do this. Even though X technically supports (or rather, has mechanisms that allow) programs switching X servers, in practice, no programs actually can do this. VNC cheats by having an X server on the remote machine that you can view using a remote vnc viewer on the local computer. You can always reattach the view, giving the appearance that you can move programs around. But in reality, they are still running on the same dummy X server on the remote machine.

Negated Void · Post by **Negated Void** » Sun Mar 05, 2006 8:36 am

Sounds neat - can you do that with just a single program? (I'd heard that VNC was more like remote desktop).

RoundsToZero · Post by **RoundsToZero** » Sun Mar 05, 2006 12:55 pm

xmove is the name of the program that does this. It is limited and buggy, though it seems that work is progressing slowly on a 2.0 version, for which there are betas.

One limitation is that, like VNC, you have to have the application initially connect to a special xmove virtual X server (like :1). Then xmove immediately forwards the application to your default display (like :0.0). At this point, however, you can theoretically have xmove move the window to another display (localhost:10.0 in the case of SSH forwarding).

Of course with any of these things, the machine that you originally started the application on can't be rebooted or shut down, since that is where the application is running, even if it's being displayed somewhere else. However, the X server on the machine can be shut down without the applications skipping a beat, because the applications are really connected to the xmove virtual X server. In fact if I remember one of the features of xmove, you can move all windows to "nowhere" which means they are connected to the xmove virtual X server but xmove isn't forwarding them to any real display. Then you can restart your X server and tell xmove to move everything back to the real display. This way you can preserve your running windows across X server restarts. It's like session saving, except with session saving, applications are shut all the way down and started back from scratch, which takes longer.

Abraxa · Post by **Abraxa** » Sun Mar 05, 2006 10:50 pm

Thanks a ton for the hint, RoundsToZero, xmove is EXACTLY what I was looking for!

-Soeren

truc · Post by **truc** » Sun Mar 05, 2006 10:58 pm

wow xmove sounds interesting to me too, thx, I've been looking for something like this for a while!

Mad Merlin · Post by **Mad Merlin** » Mon Mar 06, 2006 8:25 am

I looked for something like this before, and stumbled upon xmove, unfortunately they've been stuck at v2 beta2 for a good 7 years now, and the only repository that seems to have it is Debian's. I never actually got around to trying it, but it seemed to be pretty limited, and my reason for wanting it mostly went away anyways.

HTS · Post by **HTS** » Thu Mar 16, 2006 7:42 pm

Any news on this? I am currently running apps from the server of the university using X11Forwarding. But I can't install anything on this server... Do you know a way of briging to my display an already running app? Is Xmove the only way to go? I Obviously can't install a vnc server on the machine...