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High Performance Computing in Luxembourg

FAQ: X11 Forwarding Not Working With Slurm

Due to an issue on iris, the X11 forwarding option is not working:

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$> ssh -Y iris-cluster
(access)$> scontrol show config |grep -i PrologFlags     
PrologFlags             = Alloc,Contain,X11                      # Embedded module is indeed enabled
(access)$> printenv DISPLAY     # OK
localhost:69.0
(access)$> xeyes    # OK
(access)$> si --x11
svarrette@iris-001(iris-cluster) ~(81548 1N/1T/1CN)> printenv DISPLAY     # as expected
localhost:69.0
svarrette@iris-001(iris-cluster) ~(81548 1N/1T/1CN)> xterm     # FAILED
xterm: Xt error: Can't open display: localhost:69.0

You will need a specific script to reverse a node with X11 forwarding. You can clone this script on jbornschein srunx11 repo on Github.

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$> # Connect to iris using the X11 forwarding
$> ssh -X iris-cluster    # OR ssh -Y iris-cluster
(access)$> git clone https://github.com/jbornschein/srun.x11.git
(access)$> # Reserve an node interactively
(access)$> ./srun.x11/srun.x11  -p interactive