By "stage", I think you mean a "run" command. The doc page for the
restart command states:
"Restart files are written on timesteps that are a multiple of N and
on the last timestep of a simulation."
So if you do a series of 10000-step runs, you will get a restart
file at the end of each one. I think this did change in some recent
version. Note that they are not identical files, though they
may be the same size.