Chapter 11. Frequently Asked Questions (FAQ)

Table of Contents
What are the directories and files in my case directory?
What are CESM1 env variables and env xml files?
How do I modify the value of CESM env variables?
Why aren't my env variable changes working?
Why is there file locking and how does it work?
How do I change processor counts and component layouts on processors?
What is pio?
How do I use pnetcdf?
Is there more information about the coupler/driver implementation?
How do I create my own compset?
How do I add a new grid?
What calendars are supported in CESM?
How do I add a new component model to CESM?
How are cice and pop decompositions set and how do I override them?
How do I change history file output frequency and content for CAM and CLM during a run?

What are the directories and files in my case directory?

The following describes many of the files and directories in the $CASEROOT directory.


is the directory where the buildnml and buildexe component scripts are generated by configure. The input_data_list files are also generated by configure or the buildnml scripts and copied here.


is a directory where copies of the latest namelist/text input files from the $RUNDIR are stored. These exist only to help document the case setup and run.


is the directory that holds copies of the locked files.


is a directory where previous case configurations are stored. In other words, when configure -clean is run, the current configured scripts are copied into this directory, so when configure -case is subsequently run, there is an opportunity to review and compare previous setups.


is the Makefile Macros file for the current configuration. The Makefile is located in the Tools directory and is identical on all machines. The Macros file is a machine and compiler dependent file. This file is locked during the build step.

provides a summary of the commands used to generate this case.


contains directories for each component where case specific source code modifications can be included. The source files in these directories will always be used in preference to the source code in CCSMROOT. This feature allows users to modify CESM source code on a case by case basis if that preferable over making modifications in the CCSMROOT sandbox.


is the script that is run interactively to build the CESM model.


is the script that cleans the CESM build.


is the script that is submitted to the batch queue to archive CESM data to the long-term archive disk, like an hpss or mass storage system.


is the script that is submitted to the batch queue to run a CESM job. This script could also be run interactively if resources allow.


is a tool that checks for missing input datasets and provides a capability for exporting them to local disk.


is the script that is run to generate files in Buildconf and the build and run scripts for a case.


is a tool that generates an exact restart test in a separate directory based on the current case.

env_*.xml files

contain variables used to setup, configure, build, and run CESM.


is a directory that contains a copy of the component log files from successful case runs.


is a directory that contains timing output from each successful case run.


is a script that supports changing xml variables in the env files.


contains many scripts that are used to setup and configure the CESM model as well as run it. Some of particular note are