HP XC System 3.x Software manual HP XCCompute Node Resource Support

Serial jobs are allocated a single CPU on a shared node with minimal capacities that satisfies other allocation criteria. LSF-HPC always tries to run multiple serial jobs on the same node, one CPU per job. Parallel jobs and serial jobs cannot run on the same node.

Pseudo-parallel job	A job that requests only one slot but specifies any of these constraints:
	•	mem
	•	tmp
	•	nodes=1
	•	mincpus > 1
	Pseudo-parallel jobs are allocated one node for their exclusive use.
	NOTE Do NOT rely on this feature to provide node-level allocation for
	small jobs in job scripts. Use the SLURM[nodes] specification instead,
	along with mem, tmp, mincpus allocation options.
	LSF-HPC considers this job type as a parallel job because the job requests
	explicit node resources. LSF-HPC does not monitor these additional
	resources, so it cannot schedule any other jobs to the node without risking
	resource contention. Therefore LSF-HPC allocates the appropriate whole
	node for exclusive use by the serial job in the same manner as it does for
	parallel jobs, hence the name “pseudo-parallel”.
Parallel job	A job that requests more than one slot, regardless of any other constraints.
	Parallel jobs are allocated up to the maximum number of nodes specified
	by the following specifications:
	• SLURM[nodes=min-max](if specified)
	• SLURM[nodelist=node_list] (if specified)
	•	bsub -n
	Parallel jobs and serial jobs cannot run on the same node.
Small job	A parallel job that can potentially fit into a single node, and does not
	explicitly request more than one node (SLURM[nodes] or
	SLURM[node_list] specification). LSF-HPC tries to allocate a single node
	for a small job.

HP XCCompute Node Resource Support

The LSF host options enable you to identify an HP XC system "host" within a larger LSF cluster. After the HP XC system is selected, LSF-HPC's external SLURM scheduler provides the additional flexibility to request specific resources within the HP XC system

You can use the LSF-HPC external scheduler functionality within the bsub command and in LSF-HPC queue configurations. See the LSF bqueues(1) command for more information on determining how the available queues are configured on HP XC systems. The format of the LSF bsub command with the external SLURM scheduler option is:

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

The slurm-argumentsparameter can be one or more of the following srun options, separated by semicolons:

•nodes=min [-max]

•mincpus= ncpus

•mem=value in Megabytes

•tmp=value in Megabytes

•constraint='feature'

•nodelist= list-of-nodes

Using LSF-HPC 71