The basic synopsis of the bsub command is:

bsub [ bsub_options] jobname [ job_options]

The HP XC system has several features that make it optimal for running parallel applications, particularly (but not exclusively) MPI applications. You can use the bsub command’s -nto request more than one CPU for a job. This option, coupled with the external SLURM scheduler, discussed in Section 7.4.2, gives you much flexibility in selecting resources and shaping how the job is executed on those resources.

LSF-HPC, like standard LSF, reserves the requested number of nodes and executes one instance of the job on the first reserved node, when you request multiple nodes. Use the srun command or the mpirun command with the -srunoption in your jobs to launch parallel applications.

The -sruncan be set implicitly for the mpirun command; see Section 7.4.5 for more information on using the mpirun -sruncommand.

Most parallel applications rely on rsh or ssh to "launch" remote tasks. The ssh utility is installed on the HP XC system by default. If you configured the ssh keys to allow unprompted access to other nodes in the HP XC system, the parallel applications can use ssh.

7.4.1 Summary of the LSF bsub Command Format

This section provides a summary of the format LSF bsub command on the HP XC system. The bsub command can have the following formats:

bsub

When you invoke the bsub command without any arguments, you are prompted for a command from standard input.

bsub [bsub-options] [srun ] jobname [job-arguments]

This is the bsub command format to submit a serial job. The srun command is required to run parallel jobs on the allocated compute node. Refer to Section 7.4.3.

bsub -nnum-procs [bsub-options]jobname [job-arguments]

This is the standard bsub command format to submit a parallel job to LSF execution host. The jobname parameter can be name of an executable or a batch script. If jobname is executable, job is launched on LSF execution host node. If jobname is batch script (containing srun commands), job is launched on LSF node allocation (compute nodes). LSF node allocation is created by -nnum-procsparameter, which specifies the number of processors the job requests. Refer to Section 7.4.4 for information about running jobs. Refer to Section 7.4.6 for information about running scripts.

bsub -nnum-procs [bsub-options]srun [srun-options]jobname [job-arguments]

This is the bsub command format to submit a parallel job to LSF node allocation (compute nodes). LSF node allocation is created by -nnum-procsparameter, which specifies the number of processors the job requests. srun command is required to run jobs on LSF node allocation. Refer to Section 7.4.4.

bsub -nnum-procs [bsub-options]mpirun [mpirun-options]-srun[srun-options]mpi-jobname [job-options]

This is the bsub command format to submit an HP-MPI job. The -srunoption is required. Refer to Section 7.4.5.

bsub -nnum-procs -ext"SLURM[slurm-arguments]"[bsub-options] [srun [srun-options]]jobname [job-options]

This is the bsub command format to submit a parallel job to LSF node allocation (compute nodes) using the external scheduler option. The external scheduler option provides

7-10Using LSF