To disable metadata gathering for backups, stop the backup service, then add the metadata key that is to be filtered out to the a5backup.properties file, e.g. 'extra.data.key.filter=WIN32_SECURITY_DESCRIPTOR'. Note that only one key can be specified.
Restart the service and test a backup. A warning should be logged to indicate that the metadata is being filtered, e.g. "Filtering out extra data with key 'WIN32_SECURITY_DESCRIPTOR' from files in backup'".