I have wondered about how to manage a 100 spool of DVDs as long term cold storage of the most important data. Would need some way of splitting the data up automatically and building a straightforward burning workflow, with redundancy incase a disk is destroyed, and a way to find a given file.

Seems like a lot of work for 400-ish Gb, but 1. Its very cheap, 2. Archival disks could last a lot longer in cold storage than anything else affordable, and 3. Anyone could recover it in the future because DVD drives have been manufactured by the billion and are still being put in some office PCs. 100gb blurays are also an option but that means sourcing a burner and at least a few drives capable of reading them to store alongside.

Edit: at first blush, plain files to make recouvery easier plus par2 files scattered across enough disks to be able to lose a whole disk or have many damaged disks seems like the right format. Some sort of index would need to be built and left on every/most disks or maybe printed on paper. Its mainly the workflow to do it that would be a PITA. Then maybe vacuum seal the spool with some moisture and oxygen absorbers and put in a lightproof container. Good for decades later? Maybe.