I am looking for a good solution for redundancy backup with external drives. What would be the best way to achieve this? (1) Raid 1, mirror external drive 8tb (4tb mirror raid) (1) 4TB external drive I would like to store all my work on the raid 1 mirror drive but have an exact duplicate copy of all the data on a separate external drive. -What is the best way to mirror both drives? -Instead of copy and pasting the data is there a software that can check for duplicate files and copy only new data?