Answer
The Workflow Persistence is configured during the installation of Workflow Solution Server/Designer 6.5. If you would like to change the persistence method to either file or SQL after the installation, you can use one of the following options to open the tool:
"C:\Program Files\Altiris\Workflow Designer\Tools\Storage Configuration Change"
or
"C:\Program Files\Altiris\Workflow Designer\Ensemble\dbtool.exe" noensemble
Please note that the default setting in dbtool.exe is "file based" which will be displayed regardless of the current setting.
Changing the persistence method will remove any persisted data from your currently deployed projects.
To verify your existing Workflow Persistence settings refer to kb 45661.