Thanks for the link, Paul. Its always worth reviewing the archival
media questions.
The superiority of Phthalocyanine dye on a gold and silver discs has
been confirmed by several tests made around 2005 like the one you
link. If anyone has come across more recent tests, I'd love to know
about them.
As long as one can work work the 700mb limit of CDR's, the "Gold +
Phthalocyanine dye" discs that Mitsui and Kodak make might be the
"best bet" archival media at this point (approx $1.60USD each ). A
number of the studies I read stressed the importance of using a
quality burner, running "bleer" tests to confirm that it is working
up to spec and storing a same model burner/reader with the media.
Archival DVD-R's are more complicated. Some sources are now reporting
that the DVD recording lasers can't burn the Phthalocyanine dye at
the higher speed necessary for writing to DVD's. Both Mitsui and
Taiyo Yuden don't specify the dye they use in their DVD-R discs--
including the newest gold media and the older silver base discs (both
rated at 100+ years). It stands to logic that neither dye is as
stable as Phthalocyanine dye but there's no way to be certain.
Mitsui now makes a DVD Gold "Archival" disc (dye unspecified) that
goes for around $2.60USD each that is rated with an "expected
lifetime of well over 100 years." If one has around 100GB of data to
worry about, might be worth burning 25 of these discs as another
back-up.
I've not experienced data loss on discs like Scott reports. I've used
almost entirely Mitsui and Taiyo Yuden media and burn my discs with a
tested burner.
Its interesting to read that folks are using redundant drives as a
primary storage medium. Maybe drive hardware, stored under the right
conditions will work fine in 30-50 years. It might be faster to
convert data from a drive to the improved media that come along than
from optical disks. However, it could also become a headache to mount
current drives or a disc reader on a computers made even 15 years
from now. Certainly, both drives and optical discs will look ancient
in 100 years. Consider the challenge of mounting a SCSI drive on a
computer produced in 2009.
I'm burning lots of DVD-R discs but also placing "select" material on
redundant drives. It would already be a quite a task to place my
disc material on drives and the amount grows daily. It will take a
lot of effort to access our recordings in 50-100 years no matter what
medium we use if its not upgraded long before then. I'm gambling that
I'll still be able to cope with the number of discs I have when a
much better option surfaces. Rob D.
=3D =3D =3D =3D
At 9:04 AM +1000 9/29/09, Paul Jacobson wrote:
>
>
>There is a study on the stability of optical media on the American
>Institute for Conservation website that is well worth reading.
>
><http://cool.conservation-us.org/coolaic/sg/emg/library/pdf/iraci/relative=
StabilitiesOpticalDiscs.pdf>http://cool.conservation-us.org/coolaic/sg/emg/=
library/pdf/iraci/relativeStabilitiesOpticalDiscs.pdf
>
>cheers
>Paul
>
>On 29/09/2009, at 1:15 AM, Scott Fraser wrote:
>
>> <<I've just re-checked my oldest CDR, from 1995. It's fine.>>
>>
>> OTOH both versions of a music client's album multitrack data back up
>> on mid-market (TDK, Sony or Maxell, I forget,) DVDs from only 4 years
>> ago have failed to read in 3 different DVD-ROM drives, thus rendering
>> a remix impossible. Both copies were verified at the time they were
>> burned. I remain skeptical due to this rather unpleasant
>> unprofessional experience. What can you tell clients? "Your album
>> files have been backed up, redundantly, yet they still may be lost
>> forever as soon as I wipe my work drive"?
>>
> > Scott Fraser
>>
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