Running an interactive job
Jobs usually run in batch mode. It is then impossible to interact with the job and the script must require no humain action. For debugging and testing purposes, it is often useful to be able to interact with the program. Instead of launching the program on a login node, we recommend to run an interactive job. This is done through the -I flag at job submission.
For example, with Torque, the following command:
[name@server $] qsub -I -l nodes=3:ppn=8 -l walltime=3:00:00 [other options]
will give you 3 dedicated compute nodes and will start a shell on the master node. With Moab, you will instead use
[name@server $] msub -I -l nodes=3:ppn=8 -l walltime=3:00:00 [other options]
To run a job with an X Window graphical interface on the compute nodes, add option -X together with -I when using Torque. Beforehand, make sure that you can use X Window from the submission node, otherwise graphical display will fail miserably.