How to best use scratch

From ALICE Documentation

How to best use local scratch

In general, the best way to use the local scratch file system on /scratchdata is to copy your input files from your directory on /home or /data to the local scratch at the start of a job, create all temporary files needed by your job on the local scratch (assuming they don't need to be shared with other nodes) and copy all output files at the end of a job back to your /home or /data directory.

There are two things to note:

  • On the node that your job is running on, a directory will be created for you upon the start of a job. The directory name is /scratchdata/${SLURM_JOB_USER}/${SLURM_JOB_ID} where SLURM_JOB_USER is your ALICE username and SLURM_JOB_ID is the id of the job. You do not have to define these two variables yourself. They will be available for your to use in your job script.
  • Do not forget to copy your results back to /home or /data! The local scratch space will be cleaned and the directory will be removed after your job finishes and your results will be lost if you forget this step.