Hi @asho,
Those two files (.mdf and .ldf) act as backups for Sample Tracking that occurs during a run. Sample Tracking manages a lot of data (barcodes, volumes, transfers, etc.), which may need to be referred to in the future, so creating backup files helps prevent loss of this data if issues with the SQL Server/Database arise.
To expand on this, the SQL Server that is installed alongside VENUS has a maximum capacity of 10GB, which can get filled up quickly with regular instrument usage. As such, when a run starts, a unique Database is attached to the Server, which stores the Sample Tracking information. When the run ends, those backup files are generated and the unique Database is detached from the Server to open room for future runs. If the backup files were not generated, then the Sample Tracking data would be lost when the Database is detached.
Thank you,
Dan