keep mpirun going

user-guide/mpirun.md

@@ -0,0 +1,13 @@
+# 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
+```
+