When working with a dedicated HPC server for open-source FEM and DEM simulations, one of the first practical challenges is not computational power, but the reliable management of long-running jobs.
Solvers such as OpenFOAM, CalculiX, Code_Aster, and OpenRadioss may run for hours or even days, while SSH sessions can be interrupted by network problems, laptop shutdowns, or simply by moving between different locations and devices. This makes a persistent terminal environment an essential part of the daily workflow.
This is where tmux, a terminal multiplexer, becomes particularly useful. It allows computational jobs, monitoring tools, logs, and interactive shells to remain active on the server independently of the SSH connection. The user can disconnect, reconnect later even from a different computer or a mobile device and resume exactly where they left off.

For both single-node workstations and larger HPC or cloud-based computing environments, tmux provides a lightweight and flexible foundation for managing interactive computational workflows. Combined with SSH, shell scripting, job-management tools, and appropriate monitoring solutions, it can become an effective component of a robust and convenient environment for everyday open-source FEM/DEM computational work.
With just a few simple commands, it is possible to create persistent sessions and even complete terminal layouts dedicated to monitoring running simulations. These environments can be tailored to the specific workflow, keeping shells, solver output, logs, and monitoring tools organized and immediately available. Moreover, dedicated scripts can be created for each individual use case, allowing entire simulation environments to be set up consistently and launched with a single command.