Xterm issues

kris.c · 01-03-2008, 04:22 AM

Hi,
I am trying to debug an MPI program by launching the job on two machines and tracing through the library on both sides. For this, I need to have xterm spawn two debug windows, one for my node and one more for the remote node. I am passwordless-ly ssh-ing into the other node by using the -X switch and this is where I am now,

Code:

   
 mpirun --prefix /usr/local -hostfile machines -np 2 xterm -e gdb peruse_ex1
xterm Xt error: Can't open display:
xterm:  DISPLAY is not set

However, on doing :

Code:

 mpirun --prefix /usr/local -hostfile machines -x DISPLAY -x PATH -np 2 xterm -e gdb peruse_ex1

I am able to spawn a debug window but it is being displayed on the remote node and not on my screen . I have set the DISPLAY variable on both the nodes to be 0.0. Please let me know what I can do to have the window displayed on my node.

Thanks

mackdav · 01-03-2008, 09:02 PM

You can check this quickly:

Just ssh -X @remotesystem, then echo $DISPLAY. It should be something like localhost:10.0 If it isn't set, you can try ssh -Y user@remotesystem and echo $DISPLAY. If it works, then use -Y in your command

If it still isn't set, then there's the possibility that remotesystem is set up to deny X forwarding (look in /etc/ssh/sshd_config for X11Forwarding no (you'll need to be root to do that).

If there are no firewalls between localsystem and remotesystem, you can do this:

localsystem$ xhost + remotesystem

remotesystem$ export DISPLAY=remotesystem:0.0
remotesystem$ mpirun ...

...however the X data will not be tunneled if you do it that way.