6 Oct
2007
6 Oct
'07
8:10 a.m.
"Barry Watzman" <Watzman at neo.rr.com> wrote:
The subject of optical media longevity is one of
considerable debate. All
studies by the media makers suggest a life of several decades to centuries,
but some skeptics insist on saying less than 10 years. I have optical CD
media that is now 12 years old that I can still read just fine.
While I like to pontificate on the subject too, in my experience
scratches that damage the reflective layer are clearly (no pun intended)
responsible for 95% of CD failures I've witnessed. I too have CD-R
disks in the 10-12-14 year old range that read just fine. I have torture
tested by exposure to direct sunlight at elevated temperatures for
several years at a time and it still reads just fine (I know, not the
same as a real BER test, ...)
I think
that some of your practices are excessively conservative (such as only
applying power when the drives are being used), but will do no harm.
I have found that CD-R burners rarely last more than 3 years. Actually
the latest one I have is on its fourth year... maybe they fixed something
in the past couple of years, or maybe I'm just lucky! (Probably just
lucky because other ones in the farms at work die after 2 or 3 years.)
Many OS's are not happy about IDE or SCSI drives connecting/disconnecting
without a reboot, although I know some tricks for Linux.
The
biggest risk, I think, is burning with a marginal burner (low laser power
and/or bad or just dirty optics). Reading the media with a variety of
drives other than the one used for burning is certainly not a bad idea, but
for most users is unacceptably time consuming.
I think it's wise to do at least spot-checks.
Tim.