# Simulation not saving trajectory or moving forward

**URL:** https://gromacs.bioexcel.eu/t/simulation-not-saving-trajectory-or-moving-forward/8526
**Category:** User discussions
**Created:** [March 6, 2024, 6:38am UTC](https://gromacs.bioexcel.eu/t/simulation-not-saving-trajectory-or-moving-forward/8526 "2024-03-06T06:38:16Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![alexmathew](https://avatars.discourse-cdn.com/v4/letter/a/f4b2a3/32.png) [@alexmathew](https://gromacs.bioexcel.eu/u/alexmathew)
#### Post date: [March 6, 2024, 6:38am UTC](https://gromacs.bioexcel.eu/t/simulation-not-saving-trajectory-or-moving-forward/8526/1 "2024-03-06T06:38:16Z")

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GROMACS version:2023  
GROMACS modification: Yes/No  
Here post your question  
Im running a small peptide simulation in water, peptide is a random coil. After 93 ns simulation is not updating, i checked both log files and xtc files and found that even after running for 24 hrs it is not going further. (mdp is set for 1000 ns.)

i have restarted the simulation with bigger box size, still same issue

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<div class="post-metadata">

### Author: ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)
#### Post date: [March 6, 2024, 8:00am UTC](https://gromacs.bioexcel.eu/t/simulation-not-saving-trajectory-or-moving-forward/8526/2 "2024-03-06T08:00:48Z")

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What are the last lines in the log file and stdout and stderr?

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<div class="post-metadata">

### Author: ![alexmathew](https://avatars.discourse-cdn.com/v4/letter/a/f4b2a3/32.png) [@alexmathew](https://gromacs.bioexcel.eu/u/alexmathew)
#### Post date: [March 6, 2024, 4:54pm UTC](https://gromacs.bioexcel.eu/t/simulation-not-saving-trajectory-or-moving-forward/8526/3 "2024-03-06T16:54:49Z")

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it shows :step 22490600, will finish Tue Mar 12 12:58:42 2024  
step 22490700, will finish Tue Mar 12 12:58:42 2024imb F 6% pme/F 0.80  
step 22490800, will finish Tue Mar 12 12:58:42 2024  
step 22490900, will finish Tue Mar 12 12:58:42 2024imb F 6% pme/F 0.80  
step 22491000, will finish Tue Mar 12 12:58:42 2024  
step 22491100, will finish Tue Mar 12 12:58:42 2024imb F 7% pme/F 0.79  
step 22491200, will finish Tue Mar 12 12:58:42 2024  
step 22491300, will finish Tue Mar 12 12:58:42 2024imb F 5% pme/F 0.79

I have restart the simulation with -cpi flag it continues. but why it occur?