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:

  1. 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