BwUniCluster3.0/Slurm

Slurm HPC Workload Manager

Specification

Slurm is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for large and small Linux clusters. Slurm requires no kernel modifications for its operation and is relatively self-contained. As a cluster workload manager, Slurm has three key functions. First, it allocates exclusive and/or non-exclusive access to resources (compute nodes) to users for some duration of time so they can perform work. Second, it provides a framework for starting, executing, and monitoring work (normally a parallel job) on the set of allocated nodes. Finally, it arbitrates contention for resources by managing a queue of pending work.

Any kind of calculation on the compute nodes of bwUniCluster 2.0 requires the user to define calculations as a sequence of commands or single command together with required run time, number of CPU cores and main memory and submit all, i.e., the batch job, to a resource and workload managing software. bwUniCluster 2.0 has installed the workload managing software Slurm. Therefore any job submission by the user is to be executed by commands of the Slurm software. Slurm queues and runs user jobs based on fair sharing policies.

Slurm Commands (excerpt)

Important Slurm commands for non-administrators working on bwUniCluster 3.0.

Slurm commands	Brief explanation
sbatch	Submits a job and puts it into the queue [sbatch]
salloc	Requests resources for an interactive Job [salloc]
scontrol show job	Displays detailed job state information [scontrol]
squeue	Displays information about active, eligible, blocked, and/or recently completed jobs [squeue]
squeue --start	Returns start time of submitted job [squeue]
sinfo_t_idle	Shows what resources are available for immediate use [sinfo]
scancel	Cancels a job [scancel]

• Slurm Tutorials
• Slurm command/option summary (2 pages)
• Slurm Commands