There is a fairly important distinction between Write Once (-R) and Read/Write (R/W) CDs that the article does not cover (in case you were about to rush out and buy yourself a DLT).

On a CD-R the data layer sits below the reflective layer and it is the one that is burned permanently. CD-R/W discs have a metallic layer which is just heated at different rates to produce different spots that can be interpreted by a laser as being a 0 or a 1.

In feedback on this article, someone complained that ComputerWorld was unfairly comparing the permanent process of a CD-R with the rather less permanent one of a CD-R/W. To confuse things even more, the situation is reversed with DVDs. Read-Write DVDs apparently last longer than the write-once variety, because of the metal alloys used.

What about the environment? Well this office is certainly a cool, dark, place, so no worries there. Perhaps I could just move everything onto hard drives? Not so fast, cautions Gerecke. Hard drives are not perfect either. If the disk bearing is an el cheapo, then your precious data is also at risk. The most reliable back-up medium seems to be magnetic tape, which has a life span of 30 to 100 years if kept properly.

All of this is somewhat worrying. To be sure, I have no back-up and storage problems now, but I am concerned that, in the next three to five years, I will have to make sure that tape back-up is used for practically everything here.