Cloning a case (Experts only)

This is an advanced feature provided for expert users. If you are a new user, skip this section.

If you have access to the run you want to clone, the create_clone command will create a new case while also preserving local modifications to the case that you want to clone. You can run the utility create_clone either from $CCSMROOT or from the directory where you want the new case to be created. It has the following arguments:


The name or path of the new case.


The full pathname of the case to be cloned.


Enables silent mode. Only fatal messages will be issued.


Echoes all settings.


Prints usage instructions.

Here is the simplest example of using create_clone:

> cd $CCSMROOT/scripts
> create_clone -case $CASEROOT -clone $CLONEROOT 

When invoking create_clone, the following files are cloned in the new $CLONEROOT case directory. Note that the new case directory will be identical to the cloned case directory except for the original cloned scripts $CASEROOT.$, $CASEROOT.$MACH.clean_build, $CASEROOT.$, and $CASEROOT.$MACH.l_archive, which will have new names in the new case.

Important:: Do not change anything in the env_case.xml file. In addition, if you want to modify env_conf.xml, the new case will no longer be a clone, and you will need to configure -cleanall, which removes all files associated with all previous invocations of the configure script. The $CASEROOT/ directory will now appear as if create_newcase had just been run -- with the exception that local modifications to the env_* files are preserved. The Buildconf/ directory will be removed, however. As a result, any changes to the namelist generation scripts in Buildconf/ will not be preserved. Before invoking this command, make backup copies of your "resolved" component namelists in the Buildconf/ directory if modifications to the generated scripts were made.

Another approach to duplicating a case is to use the information in that case's file to create a new case. Note that this approach will not preserve any local modifications that were made to the original case, such as source-code or build-script modifications; you will need to import those changes manually.