You stated what you backup to a 1TB HDD. What is the size of the Synology NAS. I do not use any backup software for my Western Digital 12TB Raid5 DX4000 NAS. I copied the music files directly to 3 4TB USB My Books external drives ($139.00 each) and store them away from my house. I do not compress my music library. This way if things change like a different Raid controller or playback system all will be compatible. It takes more time but well worth it.
