OpenPBS vs Slurm Workload Manager

OpenPBS schedules jobs and manages workloads in high-performance computing environments, including clusters, clouds, and supercomputers. Its policy-driven scheduling balances job turnaround time and system utilization while selecting job placements. The system is designed for millions of cores and has been tested beyond 50,000 nodes. A plugin framework provides administration visibility and supports customized extensions. Health checks monitor faults and can mitigate them automatically; the fail-over architecture is designed to avoid a single point of failure and keep jobs running through failures. OpenPBS is self-hosted and free under the AGPL 3.0 open-source license, while PBS Pro is also dual licensed commercially. Public-sector organizations such as academic and research facilities generally choose the open-source license. Community help comes through a volunteer forum, without a guarantee of answers or bug fixes. OpenPBS is integrated into the OpenHPC software stack. The installation guide states that SELinux is not supported, and critical and high security fixes are delivered in the next major release.

Slurm Workload Manager is free, open-source software for allocating compute resources and scheduling work across Linux clusters. It starts and monitors jobs on allocated nodes and manages queues of pending work. Optional plugins add accounting, advanced reservations, gang and backfill scheduling, topology-aware resource selection, resource limits, and multifactor job prioritization. The system uses a central slurmctld manager and slurmd daemons on compute nodes; accounting and REST components are optional. GPU plugins support NVIDIA, AMD, Intel, AWS Trainium, and AWS Inferentia accelerators, along with NVIDIA MPS and GPU sharing. Accounting can use MySQL or MariaDB and can record data in a text file, directly in a database, or through slurmdbd for multiple clusters. Slurmrestd provides REST access, but the API is not designed for direct internet exposure and supports only unencrypted HTTP. Linux is thoroughly tested on arm64, ppc64, and x86_64; FreeBSD and NetBSD support is limited, and macOS is unsupported. Deployment is self-hosted.