Hi Brigitte, On Thu, Sep 28, 2017 at 02:51:53AM -0600, Selch, Brigitte (FIDF) wrote: > We have a cluster with one headnodes and x computenodes. > Scratch Filesystems are locally attached to the headnode, so the MPI task > which makes I/O should run on headnode. > But how can I determine, which node will be the batchhost? > > So far I only defined in my sbatch-script: > #SBATCH --ntasks=120
you can try with: #SBATCH -w headnode --ntasks=120 Where headnode is the hostname of your headnode. This should ensure that at least one task runs on the headnode. If this task doesn't have id 0 in your mpi prgram you can always change your code by checking the MPI_Get_processor_name in all your tasks and changing the I/O task id from 0 to the first task matching the headnode hostname on all your nodes. I hope I made myself clear. Best regards -- Gennaro Oliva
