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Non-GUI Interactive

Obtaining interactive resources for non-GUI interactive applications

This page will help you to run the queuing system commands to obtain an interactive allocation.

Log in to the headnode

First of all, log in to the cluster headnode.

Request an interactive allocation

If you don't have a Project Code, see here.

Request an allocation of 1 node with the 'salloc' command, giving the following parameters:

-N 1Request 1 physical node.
-p computeRequest the 'compute' partition.
--reservation=applicationRequest the 'application' reservation.
-t 4:00:00Request 4 hours of time.
[neil@lonsdale01 ~]$ salloc -N 1 -p compute --reservation=application -t 4:00:00
salloc: Job is in held state, pending scheduler release
salloc: Pending job allocation 10077
salloc: job 10077 queued and waiting for resources
salloc: job 10077 has been allocated resources
salloc: Granted job allocation 10077
<<JOB #10077>> [neil@lonsdale01 ~]$

You have now been allocated a single node. This has been placed in the $SLURM_NODELIST environment variable.

Note that the prompt changes, to include the job id.

You can check which node(s) have been allocated:

<<JOB #10077>> [neil@lonsdale01 ~]$ echo $SLURM_NODELIST
<<JOB #10077>> [neil@lonsdale01 ~]$

You can now ssh to the allocated node.

<<JOB #10077>> [neil@lonsdale01 ~]$ ssh $SLURM_NODELIST
Last login: Thu Jul 16 13:36:43 2009 from
[neil@lonsdale-n016 ~]$

Again, note that the prompt changes, this time to reflect that you are now logged into your allocated node, rather than just being logged into the cluster headnode.

Run your GUI application. (e.g. octave)

[neil@lonsdale-n016 ~]$ module load apps octave
[neil@lonsdale-n016 ~]$ octave

Log out or job time-out

Once you have finished running your application, you should log out of the allocated node (type exit), and then finish the allocation (again type exit).

This will free up the resources again for other users of the system.

[neil@lonsdale-n016 ~]$ exit
Connection to lonsdale-n016 closed.
<<JOB #10077>> [neil@lonsdale01 ~]$ 
<<JOB #10077>> [neil@lonsdale01 ~]$ exit
salloc: Relinquishing job allocation 10077
salloc: Job allocation 10077 has been revoked.
[neil@lonsdale01 ~]$ 
[neil@lonsdale01 ~]$ 

Finally, you are back to a normal prompt on the cluster headnode, with no job id.

Note that if you run out of your allocated time, then the job will be killed automatically, leaving you back on the cluster headnode.