Author Topic: Archive DVDs, 160 years  (Read 1545 times)

Offline sluka

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Offline DavidGibson

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Re: Archive DVDs, 160 years
« Reply #1 on: July 04, 2013, 03:44:24 pm »
That's very interesting, Martin.  I have been trying to find an answer to the problem of long-term data storage for some time now. Ive just posted my original question to the CREG forum at http://british-caving.org.uk/phpBB3/viewtopic.php?f=27&t=1198 and I think  the URL you've just posted might go a long way to answering it
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Offline jarvist

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Re: Archive DVDs, 160 years
« Reply #2 on: July 04, 2013, 10:39:16 pm »
I'm extremely dubious - it reads like snake oil. The 'test' certificate is a farce, and seems to suggest that extrapolating from 3 data points (off 300-10000hrs) at accelerated testing at 60/70/80C, you can then fit a simple exponential and extrapolate out to 160 years. I also don't understanding what they mean by 'metal substitutes an organic dye', I don't see how that's possible (or even desirable), I believe DVD-r technology use a Phthalocyanine dye, which can be in a metal complex but that has no direct bearing on lifetime!

There are archival quality DVD and CDR media available (from big reputable companies), I think either JVC or Sony recently released some DVD media which is compatible with standard equipment, and Kodak used to do a 'ultimate gold' CDR which was meant for 100 hrs.

Predictions of degradation time are a challenge - accelerated testing is no guarantee.

Offline timrivett

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Archive DVDs, 160 years
« Reply #3 on: July 04, 2013, 10:54:02 pm »
This the National Archives guidance on digital storage.
http://www.nationalarchives.gov.uk/documents/selecting-storage-media.pdf

I read this to be, keep multiple backups and re-write to new disks on a regular basis (or we could just revert to paper...)

Offline graham

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Re: Archive DVDs, 160 years
« Reply #4 on: July 04, 2013, 11:02:09 pm »
(or we could just revert to paper...)

Archive quality, acid-free paper of course. No medium lasts forever, accept that and produce a protocol for regular copying onto new media, of whatever form. And, to quote a very sensible IT pundit no file should be considered to exist until there are at least two separate copies.
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