A partial-node MPI job failed to start using Intel MPI mpiexec
A partial-node MPI job may fail to start using mpiexec from intelmpi/2019.3 and intelmpi/2019.7 with error messages like
OSC internal network problems 25 Sept. 2020
OSC is currently experiencing problems with its internal network. Interactive sessions may be slow or unresponsive, but running jobs should not be affected.
OpenMPI job stopped at 'There are not enough slots available in the system to satisfy the slots'
Users would encounter a MPI job failed with openmpi/3.1.0-hpcx on Owens and Pitzer. The job would stop with the error like "There are not enough slots available in the system to satisfy the slots". Please switch to openmpi/3.1.4-hpcx. The buggy version openmpi/3.1.0-hpcx will be removed on August 18 2020.
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Resolved: We removed openmpi/3.1.0-hpcx on August 18 2020.
cuda-gdb segmentation fault on startup
The CUDA debugger, cuda-gdb, can raise a segmentation fault immediately upon execution. A workaround before executing cuda-gdb is to unload the xalt module, e.g.:
module unload xalt
This issue affects most cuda modules on Pitzer and Owens.
Error 'libim_client.so: undefined reference to uuid@' with MVAPICH2 in Conda environment
Users may encoutner an error like 'libim_client.so: undefined reference to `uuid_unparse@UUID_1.0' while compiling MPI applications with mvapich2 in some Conda enivronments. We found pre-installed libuuid package from Conda conflicting with system libuuid libraries. The affected Conda packages are python/2.7-conda5.2, python/3.6-conda5.2 and python/3.7-2019.10.
Incorrect MPI launcher and compiler wrappers with Conda environments python/2.7-conda5.2 and python/3.6-conda5.2
Users may encounter under-performing MPI jobs or failures of compiling MPI applications if you are using Conda from system. We found pre-installed mpich2 package in some Conda environments overrides default MPI path. The affected Conda packages are python/2.7-conda5.2 and python/3.6-conda5.2. If users experience these issues, please re-load MPI module, e.g. module load mvapich2/2.3.2 after setting up your Conda environment.
Jobs reports 'excessive memory usage' message
A batch job output may contain warnings about excessive memory usage.
Rolling reboot of Owens and Pitzer starting from February 3, 2020
We will have rolling reboots of Owens and Pitzer clusters including login and compute nodes, starting from Monday, February 3, 2020
Large MPI job startup hang with mvapich2/2.3 and mvapich2/2.3.1
We have found that large MPI jobs may hang at startup with mvapich2/2.3 and mvapich/2.3.1 (on any compiler dependency) due to a known bug that has been fixed in release 2.3.2. If users experience this issue, please switch to mvapich2/2.3.2.
Rolling reboot of Owens starting from Oct 10, 2019
We are having rolling reboots of Owens cluster including login and compute nodes, starting from October 10, 2019.