These files record the progress of data transfer and display errors:
errors.log—Describes errors. You can configure this file to display warning and debug messages.
failedRecords.log—Contains an entry for each record that fails to load, the record number, and if possible, the name of the object the record represents.
successfulRecords.log—Contains an entry for each loaded record. Because it will be large, modify the configuration file to generate this file.