You know all those DVDs and CDs that you burnt to “permanently” archive all your Dave Matthews mp3s or Hawaii pictures? People are finding that the data on them can begin to disappear after as little as 3 years. I think that short of a time period is a bit alarmist. But the whole situation should have you thinking.
First off, for all you speedreaders that just slowed down, this does not apply to commercial-grade DVDs like your daughter’s boxed set of Dora The Exploder DVDs. This applies to the media that you burn on your home PC. Certain kinds of adhesive and, much more rarely, inks from pens can leech into the delicate dye layer that all your data is written to. But even if you keep your discs pristine, the media is subject to data fading. Yikes, huh?
Time for the real world example so you know that I ain’t pullling this out of thin air. I have some data CDs that I used under 10 times about 6 to 7 years ago — proof that they worked well at one time. I burnt on name-brand CDs on a very high quality Plextor and HP burners, so this is not a matter of my usual cheapskate shortcuts (ask one of the growing number of my exes about that … actually, on a second thought, don’t … just take my word for it). I needed to install several of the applications on those discs for some application testing. When I went to install, only some of the apps completed the installation routine. I unfailingly got “cyclic redundacy errors” on the same files during install. And when I tried to copy the apps over from the disc to re-burn, I got the same error.
I tried the bad discs on different computers with similar results. Once in a while, one computer in the office could read a disc. However, it was never the same computer. So that shows there is not some badass system that can read any disc. If you have a failing disc though, you can try reading it on a few machines and maybe one will be able to read some … though you may get errors on different files.
The saving grace for me was that I had these files backed up to an old hard drive. I was able to burn new discs from that. So that is one solution. Another is to burn a second copy of your important discs and drop them into some sort of convenient bookshelf storage. I use one of those binders that holds four discs per page. On the backup disc, obviously don’t write anything (maybe a small number designation) and don’t use a label. You’ll still get errors, maybe even on both. But it would be highly unlikely that you’d get the SAME error on both discs. Down the road, you can always burn a new disc from the pair.
In closing, if you have Dave Matthews mp3s and you lose the files … well, then that is not an entirely negative thing. Some bad data is bad to begin with.