I have in my personal google drive, well over 100GB of documents, manuals, instructions, and other material that could potentially be valuable if we ever found ourselves without the internet long term. The cheap and easy path is to use USB thumb drives. But how long do those last? I know that CD-R discs degrade over time (I was one of those geeks burning audio and MP3 CDs in the mid 1990s.) Most still work, but some are starting to fade already.
I know the old school folks would say to print and bind it, but seriously that would cost me several hundreds of dollars and I'd need book shelves on 3 walls of a bedroom to stack it all. I'd like to stay happily married and don't feel like renting a storage unit to house a SHTF library.
I'm not paranoid about EMP, though something robust in that regard is a bonus. I'm thinking an external HDD might be practical. Keep it unplugged and in a safe place.
Also, how long is "long"? Is USB guaranteed to be an available interface a decade or longer from today? In my life we've gone from PCs with no HDD, 5.25" floppy, 3.5" floppy, CD-ROM, now the newest laptops don't have any removable media except via USB ports. Most are designed to leverage cloud storage. More than I view times I've come across an shoe box filled with floppy disks containing old projects. Point is, it may not seem that we'll outlive our present digital mediums of choice, but we likely will.
Thoughts, ideas, concerns?