Originally posted by Rondec I guess between hard drive crashes, DVD failures, etc, I am not convinced that people will be able to access their photos in the long run. I know people who had all a years worth of snaps on a couple of memory cards only to have one of them go bad, thereby losing a large percentage of their photos. Probably folks on the forum are a lot more compulsive about backing photos up in multiple ways (hard drives, cloud, blue ray disks), but in general, I think technology has tended to make people's photos more tenuous.
That's what Amazon Glacier is for, honestly. They dump your upload to cold storage (some kind of tape, I suspect) in multiple locations. As long as you keep paying the bill you're pretty much safe in practical terms. And it's 1/3 the price of space on their live servers ($0.01 per gb per month). It's still too expensive to store all 3000 of your rejected photos, but if you only upload after you've selected the keepers it's not too bad.
It's even cheaper than putting it on tapes yourself. Even ignoring the $2500 for the drive, 2.5TB tapes are $50 a pop so you're looking at $0.02 per GB.
I've experienced bitrot in my DVD backups. As the density increases (eg Bluray) the odds get even higher. Nowadays I burn a DVDisaster error recovery file to the next disc. Costs me 15% of my disc capacity but I stand at least a chance of recovering data. I also no longer use sharpies - the solvent can penetrate through the plastic over time and damage the reflective data layer. Get an archival pen at your local photo store. Also, burn as slow as you can - the faster you burn, the faster the disc spins, the shorter the exposure time. That translates into less energy is directed into each pit, which means a "less contrasty" data track that is more susceptible to bit-rot.
Also yeah, RAID is good too, for your hot storage.