DiskStation uses a multimedia database to keep track of multimedia files and log entries stored on the media source (shared folders created on your external storage devices, such as usbshare1).
Important: If you want DSM's multimedia services (such as Media Server, iTunes, Audio Station, and Download Station) to access multimedia files stored on the external storage devices connected to the USB port of your DiskStation, or if you want to enable DSM's log services and see the log records at Main Menu > System Information > Log, the multimedia database has to be enabled first. Otherwise, all related services will be deactivated.
Warning: To prevent the database from being corrupted, make sure you have ejected its storage device at Main Menu > Control Panel > External Devices before removing it from DiskStation.
Multimedia files and log records in the selected shared folders will be indexed, and the indexed information will be added to the multimedia database.
Note: If a large portion of data in the multimedia database is no longer used (for example, you disconnect a USB disk which will never be used with DiskStation again, resulting in redundant indexed information in the database), refreshing the multimedia database can help you clear all unused data or downsize the database. However, doing so requires repetitive disk reading and writing, which might consume system resources and result in shortened disk lifespan. Please use this function with discretion.