External hard drives are an option.Make certain you have at least two separate back up hard drives, as each can fail. Also, it'd be good to know whatever interface connection they provide will be around in two years when you'll have to transfer your files to the next generation of storage drives. Remember the scuzzy? Wasn't that long ago...
Gretsch6120 (Threads | Answers)
I recall buying a Syquest drive many years ago after doing a lot of research. It was the most reliable and popular external drive at the time. I backed up my files diligently. Two years later, the interface was outdated, my Syquest drive became a doorstop and the storage media became coasters.
Computer audio brings it's own set of unique problems to the hobby.