Hello all,

This is also addressed in the chat:

https://matrix.to/#/%21mYSgqyShRCoThqmUmY%3Agitter.im/%24GoGyO7PMmaXQPBip5Jj...

where the most recent issue is

--8<-- /home/jorge/simulations/ProcaStar6/SIMFACTORY/exe/cactus_sim -L 3 /home/jorge/simulations/ProcaStar6/output-0000/ProcaStar.par cactus_sim: /home/jorge/Einstein-Toolkit/Cactus/arrangements/Carpet/CarpetLib/src/th.hh:70: CCTK_REAL8 CarpetLib::th::get_time(int, int, int) const: Assertion `tl >= 0 and tl < timelevels' failed. Rank 0 with PID 57937 received signal 6 --8<--

Yours, Roland

[CAUTION: Non-UBC Email]

Dear Einstein Toolkit users,

I am currently working with the Einstein Toolkit and trying to use checkpoint/restart functionality to recover simulations.

I understand the parameters that must be included in the parameter file, but I am not sure how I should correctly restart a simulation from existing checkpoint data.

So far, I have been launching simulations with commands such as

./simfactory/bin/sim run ProcaStar -workstation-parfile=par/ProcaStar.par

and the simulation runs correctly and generates checkpoint files. However, when I try to restart from the checkpoint data, I am unsure what the correct procedure should be. I do not know whether I should use a different SimFactory command, modify the submission procedure, or provide additional options.

The checkpoint-related parameters in my parameter file are:

CarpetIOHDF5::checkpoint = yes IOUtil::checkpoint_every_walltime_hours = 0.1 IOUtil::checkpoint_dir = "checkpoints_prueba" IOUtil::checkpoint_keep = 1 IOUtil::checkpoint_ID = no IOUtil::checkpoint_on_terminate = yes IOUtil::recover = "autoprobe" IOUtil::recover_dir = "checkpoints_prueba" IOUtil::abort_on_io_errors = yes CarpetIOHDF5::open_one_input_file_at_a_time = yes

Could someone please clarify the recommended procedure for restarting a simulation from existing checkpoint files? In particular:

Which SimFactory command should be used to restart a simulation? 2.

Is it necessary to create a new run or continue the existing one? 3.

Are there any additional parameters or directory requirements for recovery to work correctly?

My environment is: Einstein Toolkit version: ET_2025_05 Operating system: Linux Ubuntu 22.04.5 LTS Cluster/machine: Local

Thank you very much for your help.

Best regards, Yahir Mio