# Start Long Running Programs/Simulations with `mpirun`

If you want to start a program with `mpirun` or based on `mpirun` in a shell session and to exit after, then `nohup`, `screen` or `tmux` are not sufficient. On exit you might get an error like
```
mpirun noticed that process rank 0 with PID 26312 on node lcth31 exited on signal 0 (Unknown signal 0).
```

To avoid this, use `disown`:

```
nohup [command] & disown
```