How Long Will a CD or DVD Last?

As with any backup medium (floppy disk, tape, CDROM, etc.) the lifetime of the data is an important consideration. Kodak has done extensive accelerated aging tests which indicate that their Infoguard CD-R should last 200 years. TDK say that their discs will last "about 100 years". Others tell horror stories that no-name CDs which they have burned are no longer readable after a few months.

Optical disk manufacturers advise that storing your backup disks in a cool, dry environment will help to prolong data life, while direct sunlight and fingerprints may cause damage to a CD or DVD. A good rule of thumb (no pun intended) seems to be to buy a brand-name disk, treat it as per the guidelines above, but don't expect it to last more than five years.

But even if your CDROM data remains intact for 50 years, will we still have CD and DVD readers commonly available then? Technology changes rapidly. When was the last time you saw a computer with a 5.25 inch floppy drive? Even the 3.5 inch floppy is an endangered species, now that most computers are sold without them. In a few decades, the CDROM may be outmoded.

I suggest you revisit your backup strategy every few years, and re-copy all critical data to new media on the same basis. Now that portable USB flash drives are getting cheaper, you might consider using them instead of optical disks.

Repairing a Damaged CD-ROM

Even if you're careful, CDs can get scratched and become unreliable or unreadable. A few years ago, I read about the Toothpaste Cure. It sounds a bit hokey, but I can tell you it has brought some CDROM disks back to life when I thought they were goners. Here's how it works:

First clean the disk with warm water and mild soap to remove any oils from fingerprints or other sources. Dry it with a clean, lint-free towel and see if the disk will work now. If not, bring on the Crest!

Rub the disk gently with toothpaste (the pasty kind, not a gel) in a RADIAL (not circular) motion from the center of the disk to the outside edge. Wash and dry it again and see if it's readable.

Some people report success when using car polish, silver polish, or Rain-X instead of toothpaste. The idea is that small scratches are buffed out, and some of the polishing agent remains on the disk to fill in any irregularities on the optical surface. Due to the chance that the filler may fall out over time and gum up your CDROM drive, you should make a copy of the repaired disk and discard the original.

It doesn't always work, but it's worth a try when the only alternative is to throw away the disk. Some commercial products that may be useful are Wipe Out! and Discwasher.

Reprinted from: http://www.askbobrankin.com/lifetime_of_a_cdrom_disk.html

BOB RANKIN... is a tech writer and computer programmer who enjoys exploring the Internet and sharing the fruit of his experience with others. His work has appeared in ComputerWorld, NetGuide, and NY Newsday. Bob is publisher of the Internet TOURBUS newsletter, author of several computer books, and creator of the http://LowfatLinux.com website. Visit Bob Rankin's website for more helpful articles and free tech support.