# Trying to restart my simulation from last checkpoint

**URL:** <https://gromacs.bioexcel.eu/t/trying-to-restart-my-simulation-from-last-checkpoint/6873>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [July 24, 2023, 5:26am UTC](https://gromacs.bioexcel.eu/t/trying-to-restart-my-simulation-from-last-checkpoint/6873 "2023-07-24T05:26:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![parul](https://avatars.discourse-cdn.com/v4/letter/p/5fc32e/32.png) [@parul](https://gromacs.bioexcel.eu/u/parul)\
**Post date:** [July 24, 2023, 5:26am UTC](https://gromacs.bioexcel.eu/t/trying-to-restart-my-simulation-from-last-checkpoint/6873/1 "2023-07-24T05:26:49Z")

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GROMACS version:  
GROMACS modification: Yes/No  
Here Post your question: I am trying to restart my simulation from the last checkpoint, which is at 122 ns. I want to rerun it up to 200 ns, but when I give the following command, it’s not happening :

**gmx mdrun -v -s pull.tpr -cpi pull.cpt -append -deffnm pull**

Output file appending has been requested,  
but some output files listed in the checkpoint file pull.cpt  
are not present or not named as the output files by the current program:  
Expect output files present:  
pull.log  
pull.xtc  
pull.trr  
pull.edr

Expected output files not present or named differently:  
pull\_pullx.xvg  
pull\_pullf.xvg

* * *

Program: gmx mdrun, version 2018  
Source file: src/gromacs/mdrunutility/handlerestart.cpp (line 179)

Fatal error:  
File appending requested, but 2 of the 6 output files are not present or are  
named differently. For safety reasons, GROMACS-2016 and later only allows file  
appending to be used when all files have the same names as they had in the  
original run. Checkpointing is merely intended for plain continuation of runs.  
For safety reasons you must specify all file names (e.g. with -deffnm), and  
all these files must match the names used in the run prior to checkpointing  
since we will append to them by default. If you used -deffnm and the files  
listed above as not present are in fact present, try explicitly specifying  
them in respective mdrun options. If the files are not available, you can add  
the -noappend flag to mdrun and write separate new parts. For mere  
concatenation of files, you should use the gmx trjcat tool instead.

For more information and tips for troubleshooting, please check the GROMACS  
website at [Common Errors — GROMACS webpage https://www.gromacs.org documentation](http://www.gromacs.org/Documentation/Errors)

Can u pls look into tell me why it is not running?

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**Author:** ![alevilla](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/alevilla/32/439_2.png) [@alevilla](https://gromacs.bioexcel.eu/u/alevilla)\
**Post date:** [July 24, 2023, 6:27am UTC](https://gromacs.bioexcel.eu/t/trying-to-restart-my-simulation-from-last-checkpoint/6873/2 "2023-07-24T06:27:08Z")

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Hi,  
the application is excepting to find to the following files in the working directory

pull\_pullx.xvg  
pull\_pullf.xvg

since it did not find them, it gave an error.  
You could check if the files are in the working directory and have the excepted name.

Best regards  
Alessandra

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<div class="post-metadata">

**Author:** ![parul](https://avatars.discourse-cdn.com/v4/letter/p/5fc32e/32.png) [@parul](https://gromacs.bioexcel.eu/u/parul)\
**Post date:** [July 24, 2023, 10:13am UTC](https://gromacs.bioexcel.eu/t/trying-to-restart-my-simulation-from-last-checkpoint/6873/3 "2023-07-24T10:13:42Z")

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yeah alevilla, the files are there I added the name of the files after deffnm in the command now it’s working