My organization currently stores, serves, and backs up about 4 TB of data. Now, out of necessity, we are converting all of our microfilm to PDF files. A vendor is doing that part, and they estimate that once converted, there will be 100TB of PDF files. I don't even know where to begin with managing that much data.
The backup medium should have a long shelf life. Otherwise, we'll be constantly re-backing up the data as the expected shelf life of the media approaches.