Interactive access is intended for code development and short runs. To run interactive jobs on Dirac, users must request compute node resources via the batch system. The following command requests 8 cores on one node using the interactive queue (and you will run on either Tesla or Fermi nodes):
% qsub -I -V -q dirac_int -l nodes=1:ppn=8
If you want to request fermi nodes (Tesla C 2050), add the fermi option:
% qsub -I -V -q dirac_int -l nodes=1:ppn=8:fermi
If you want to request tesla nodes (Tesla C 1060), add the tesla option:
% qsub -I -V -q dirac_int -l nodes=1:ppn=8:tesla
The -I flag specifies an interactive job.
The -V flag passes the environment setting from the login nodes to the interactive session.
The -q flag specifies the name of the queue.
The -l suboptions nodes= and ppn= state the number of nodes and number of tasks per node to use, respectively.
The qsub commands above will create a new shell running in your home directory. The directory from which a job is submitted is defined in the environment variable $PBS_O_WORKDIR. If your parallel application is located in this directory, you can cd there to launch the parallel interactive application with the mpirun utility:
% cd $PBS_O_WORKDIR
% mpirun -np 8 ./my_parallel_app