Interactive Jobs

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.
Other optional Torque keywords including other queues and account name can be passed as arguments.

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