From 987c708c38fbc80855bb046b08aa46743318b451 Mon Sep 17 00:00:00 2001 From: caubet_m Date: Mon, 30 Mar 2026 07:39:14 +0200 Subject: [PATCH] Update OpenMPI --- docs/merlin7/05-Software-Support/openmpi.md | 28 +++++++++++++-------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/docs/merlin7/05-Software-Support/openmpi.md b/docs/merlin7/05-Software-Support/openmpi.md index 8fe06bcd..291c2fdc 100644 --- a/docs/merlin7/05-Software-Support/openmpi.md +++ b/docs/merlin7/05-Software-Support/openmpi.md @@ -8,22 +8,28 @@ This document outlines the supported OpenMPI versions in the Merlin7 cluster. The Merlin cluster supports OpenMPI versions across three distinct stages: stable, unstable, and deprecated. Below is an overview of each stage: -#### Stable - -Versions in the `stable` stage are fully functional, thoroughly tested, and officially supported by the Merlin administrators. +* **Stable**: Versions in the `stable` stage are fully functional, thoroughly tested, and officially supported by the Merlin administrators. These versions are available via [PModules](pmodules.md) and [Spack](spack.md), ensuring compatibility and reliability for production use. -#### Unstable - -Versions in the `unstable` stage are available for testing and early access to new OpenMPI features. +* **Unstable**: Versions in the `unstable` stage are available for testing and early access to new OpenMPI features. While these versions can be used, their compilation and configuration are subject to change before they are promoted to the `stable` stage. Administrators recommend caution when relying on `unstable` versions for critical workloads. -#### Deprecated +* **Deprecated**: Versions in the `deprecated` stage are no longer supported by the Merlin administrators. Typically, these include versions no longer supported by the official [OpenMPI](https://www.open-mpi.org/software/ompi/v5.0/) project, or problematic releases. While deprecated versions may still be available for use, their functionality cannot be guaranteed, and they will not receive updates or bug fixes. -Versions in the `deprecated` stage are no longer supported by the Merlin administrators. -Typically, these include versions no longer supported by the official [OpenMPI](https://www.open-mpi.org/software/ompi/v5.0/) project. -While deprecated versions may still be available for use, their functionality cannot be guaranteed, and they will not receive updates or bug fixes. +!!! warning + Merlin7 runs as a PSI vCluster on the HPE Cray EX-based ALPS system. The native software environment + on ALPS is generally centered around Cray MPICH and other system-integrated components. However, many + PSI applications depend on OpenMPI, so we also provide and support OpenMPI builds on Merlin7. + + Our goal is to keep these OpenMPI installations as independent as practical from site-specific system + components, so that the same software stack remains usable for longer and requires fewer rebuilds. In + practice, however, the full stack still involves several low-level components and runtime dependencies. + As a result, **occasional rebuilds with newer OpenMPI releases may still be necessary**, for example to + address compatibility issues, broken dependencies, or performance problems. + + At present, we recommend using OpenMPI **5.0.8 or newer** on Merlin7, compiled with + **libfabric/2.2.0-oss** or superior. ### Using srun in Merlin7 @@ -64,7 +70,7 @@ specific pmix plugin versions available: pmix_v5,pmix_v4,pmix_v3,pmix_v2 Important Notes: * For OpenMPI, always use `pmix` by specifying the appropriate version (`pmix_$version`). When loading an OpenMPI module (via [PModules](pmodules.md) or [Spack](spack.md)), the corresponding PMIx version will be automatically loaded. -* Users do not need to manually manage PMIx compatibility. +* Users do not need to manually manage PMIx compatibility, unless they compile their own OpenMPI release. !!! warning PMI-2 is not supported in OpenMPI 5.0.0 or later releases. Despite this,