Article on data rot on CD's

From: Antonio Carlini <a.carlini_at_ntlworld.com>
Date: Wed Aug 4 13:20:53 2004

> the lightest fire) in an A/C office environment. One of
> five had an error. On the other hand, I probably didn't
> check the original for read errors after I made it.

I wonder how many reported errors are actually
write failures rather than media failures?

When I came across my first error, I started
to make sure that I always (where possible)
added some sort of CRC checksum when burning
*and* checking it after burning (and after
labelling with a marker pen) immediately
afterwards.

That used to catch a 5% failure rate back
in the days when I was using a 486 and
then a K6-233 to do the burning.

These days I don't see any burn errors any more.
I've no idea whether that's down to the faster
machine, the newer CD (now DVD) burner, the
burn-proof technology or better media.

Since then I've only had one verifiable
failure - a DVD-R that had failed within
the first year. Not good, but the overall
failure rate doesn't seem too bad. I still
write anything important to two discs though
(they're now cheap enough that anything else
seems foolish).

When disks become cheap enough I'll go back
and image all the existing CDs and DVDs.
Then I'll have both an accurate failure
rate to report and a further source of
backup data :-)

Antonio

-- 
---------------
Antonio Carlini arcarlini_at_iee.org
 
Received on Wed Aug 04 2004 - 13:20:53 BST

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