Keep two copies of my music files in sync

[Geoff_Coupe]

In which case, you might want to read this thread…

Backup of music files

So far I am backing up my music files per drag and drop from the main HDD to the backup-drives. Is there any software you would recommend for this task? I can run it on Windows, Mac and Raspberry. Or do you have any links which might be of interest regarding this topic?