When LSF runs a job, the LSB_HOSTS variable is set to the names of the hosts running the batch job. For a parallel batch job, LSB_HOSTS contains the complete list of hosts that LSF has allocated to that job.
LSF starts one controlling process for the parallel batch job on the first host in the host list. It is up to your parallel application to read the LSB_HOSTS environment variable to get the list of hosts, and start the parallel job components on all the other allocated hosts.
For running large parallel jobs, use LSB_MCPU_HOSTS. The format for this parameter is LSB_MCPU_HOSTS="host_nameA num_processors1 host_nameB num_processors2..."
LSF provides a generic interface to parallel programming packages so that any parallel package can be supported by writing shell scripts or wrapper programs.