Storage expert warns of short life span for burned CDs - Computerworld:
And don't count on hard disk drives for long-term storage, either
News Story by John Blau
JANUARY 10, 2006 (COMPUTERWORLD) - Although opinions vary on how to preserve data on digital storage media, such as optical CDs and DVDs, Kurt Gerecke, a physicist and storage expert at IBM Deutschland GmbH, takes this view: If you want to avoid having to burn new CDs every few years, use magnetic tapes to store all your pictures, videos and songs for a lifetime.
'Unlike pressed original CDs, burned CDs have a relatively short life span of between two to five years, depending on the quality of the CD,' Gerecke said in an interview this week. 'There are a few things you can do to extend the life of a burned CD, like keeping the disc in a cool, dark space, but not a whole lot more.'
The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data 'shifting' on the surface and thus becoming unreadable to the laser beam.
'Many of the cheap burnable CDs available at discount stores have a life span of around two years,' Gerecke said. 'Some of the better-quality discs offer a longer life span, of a maximum of five years.'
Distinguishing high-quality burnable CDs from low-quality discs is difficult, he said, because few vendors use life span as a selling point.
Hard-drive disks also have their limitations, according to Gerecke. The problem with hard drives, he said, is not so much the disk itself as it is the disk bearing, which "