Data Rot

“Whenever I think of the past, it brings back so many memories.” - Steven Wright

Although we live in an information age, the information we take for granted is surprising fragile. Sometimes data erasure is deliberate as when Enron is shredding documents & erasing email. Sometimes data is changed to influence public opinion as is frequent on Wikipedia (see http://www.nolanchart.com/article6235.html) Sometimes data just rots.

What is data rot? Over time, things like temperature, humidity, exposure to light, being stored in poor locations like moldy basements, make physical media very difficult to read. Do you recall when machines ate cassette tapes and videotapes? Vinyl albums that became scratched over time with hiss, crackles and track jumping? Old scratchy home movies on reels? Today’s kids laugh at the old technology and take pride in the “permanence” of CDs and DVDs.

My wife and I save money by watching movies on DVDs borrowed from the library. About one in five of these DVDs have been scratched badly enough that the player locks up. Sometimes we can skip past the bad region, sometimes not. We never saw most of “Bee Movie”; the DVD was in such poor shape.

Suppose you take great care of your DVD; how long will it last? Perhaps 100 years but also perhaps as little as Ten to Twenty years. If you have images you want to keep forever (like home movies and photos), experts recommend you make a copy of your DVD every 10 years. Unlike vinyl records, you don’t want to use the copy and keep the original unused for future copies. Cosmic rays can alter digital data and heat can warp the disc. That pristine but old DVD may become unreadable. So with DVDs use the old disc and keep the new copy in a safe place.

Bottom Line
To date there is no perfect long-term storage medium. Can you still play 8-track tapes? Does your PC have a floppy disc drive? Some have suggested the Internet as the ultimate backup. But data hosting companies go out of business or change policies. Kodak used to host photos for free but now wants to charge $5 per month. The best you can hope for a shell game where you keep moving your data to the newest technologies, trying to stay ahead of obsolescence and rot. And just like your money – DO NOT trust all your precious memories to a single storage medium. Use DVDs and multiple free websites.