Archival storage for RAW video
If your system has external SAS, you can either buy an older LTO Tape Drive System, such as an LTO-5, or rent one. Or go for an LTO-6 or 7 drive. 

Linear tape really is the best choice for a number of production environments which is why so many post houses have adopted it for footage back up. 

The tapes have large capacity, are enterprise secure, have built in fault tolerance, are fairly easy to use, and it's the CHEAPEST way to archive. 

An LTO-6 Tape will hold 2.5TB uncompressed content (raw video), will write at speeds of roughly 140mb/s and the tape will cost you about $20. 

A 2TB HDD Bare Spinning Drive is far most costly than that and will not run/be locked/greased up if you try to use it 50 years from now. 

They are archival for 30-50 years. 

It's what the National Archives uses.