# Where is checkpoint file written running mdrun with MPI-threads

**URL:** <https://gromacs.bioexcel.eu/t/where-is-checkpoint-file-written-running-mdrun-with-mpi-threads/3871>\
**Category:** User discussions\
**Created:** [March 22, 2022, 3:54am UTC](https://gromacs.bioexcel.eu/t/where-is-checkpoint-file-written-running-mdrun-with-mpi-threads/3871 "2022-03-22T03:54:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![bjwiley23](https://avatars.discourse-cdn.com/v4/letter/b/c6cbf5/32.png) [@bjwiley23](https://gromacs.bioexcel.eu/u/bjwiley23)\
**Post date:** [March 22, 2022, 3:54am UTC](https://gromacs.bioexcel.eu/t/where-is-checkpoint-file-written-running-mdrun-with-mpi-threads/3871/1 "2022-03-22T03:54:47Z")

</div>

GROMACS version: 2021.5  
GROMACS modification: Yes compiled with `-DGMX_THREAD_MPI=ON -DMPI_C_COMPILER=mpicc`

I am getting an error that has been seen before but to get troubleshooting help from my Cluster admins I need to know where the checkpoint files are being written/read to when running with `mpirun`. This is the error that happen when you probably do not have permissions to the folder on the cluster nodes:

```auto
Source file: src/gromacs/mdlib/mdoutf.cpp (line 463)
MPI rank: 0 (out of 16)

File input/output error:
Cannot rename checkpoint file; maybe you are out of disk space?

```

I run with in a directory on my own LSF storage so I have access here

```auto
mpirun --wdir . -np 16 /usr/local/gromacs/bin/gmx mdrun -ntmpi 16 -ntomp 6 -npme 4 -ntomp_pme 1 -deffnm md_0_1 -nb gpu

```

So my admins need to know where might mpi be reading and writing from?