Checkpoint / Restart

ERF has a standard sort of checkpointing and restarting capability and uses the native AMReX format for reading and writing checkpoints. In the inputs file, the following options control the generation of checkpoint files (which are really directories):

Writing the Checkpoint “Files”

List of Parameters

Parameter	Definition	Acceptable Values	Default
erf.check_file	prefix for restart files	String	“chk”
erf.check_int	how often (by level-0 time steps) to write restart files	Integer \(> 0\)	-1
erf.check_per	how often in simulation time to write restart files	Real \(> 0\)	-1.0

Restarting

Parameter	Definition	Acceptable Values	Default
erf.restart	name of the file (directory) from which to restart files	String	not used if not set

Examples of Usage

• erf.check_file = chk_run

• erf.check_int = 10

  means that restart files (really directories) starting with the prefix “chk_run” will be generated every 10 level-0 time steps. The directory names will be chk_run00000, chk_run00010, chk_run00020, etc.

• erf.check_per = 5.0

  means that restart files (really directories) starting with the prefix “chk_run” will be generated whenever the simulation time passes a multiple of 5.0. The directory names will reflect the integer number of steps which have elapsed.

To restart from chk_run00061,for example, then set

• amr.restart = chk_run00061