My 2 year old can ruin a CD/DVD after about 2 handles...not in 2 year..in
about 2 days. One tiny scratch on a Cd/DVD and it won't play. Hopefully he
continues to ruin the Barney set:-))
As someone in the commercial media services businesses almost no companies
use Cd/DVD media to archive data. They all use tape. If you have something
valuable to keep tape can be migrated to other formats if it has been stored
properly.
Michael Marchand
VeriTrust
On 12/6/06, Ronald W. Frazier <[log in to unmask]> wrote:
>
> Hello all,
>
> I've just come across a document I wanted to pass along. Please excuse
> cross postings. Although I'm a fan of using gold CD's and DVD's for
> storage purposes, as opposed to other types of CD's and DVD's, I have to
> admit that they are not suitable for all projects and all purposes. I
> also
> have to admit that using them has its own set of challenges and
> problems. My mission is to work with people to come up with viable
> solutions to their unique data preservation needs. I found the document
> below from a link in the Association for Recorded Sound discussion
> list. It talks about the risks and implications of using CD's and DVD's
> for long term storage. It discusses the need for testing of discs before
> and after use, for maintaining redundant copies of data, testing error
> levels on an ongoing basis, and migrating to new media. Overall, it's a
> very well written document. Worth checking out.
>
> MEMORY OF THE WORLD
> PROGRAMME
> Sub-Committee on Technology
>
> Risks Associated with the Use of Recordable CDs and DVDs as
> Reliable Storage Media in Archival Collections - Strategies and
> Alternatives
>
> http://unesdoc.unesco.org/images/0014/001477/147782E.pdf
>
> This got me to thinking on a couple of points, and I'd like your opinion
> on
> them. This could apply to other media as well.
>
> First, redundant data. He recommends a strategy of keeping a Master copy,
> a Working copy, and a Safety copy. The Safety copy is stored offsite. He
> also recommends that the Master and Safety copies be from different
> manufacturers if possible to mitigate potential problems with a particular
> formulation.
>
> In other reading I've done, I've heard a slightly different strategy. I
> believe this comes from the video environment, although I can't remember
> for sure. In this case, you have the Master, Copy Master, and Access
> Copy. The Master is only used to make duplicate Copy Masters. The Copy
> Masters are used to make duplicate Access copies. The Access copies are
> the same as the Working copies above. Thus, the Master is only rarely
> accessed, only when a new Copy Master must be made. The Copy Masters are
> used as often as necessary to make Access copies for general use. If we
> add the Safety master from the above paragraph, that will mean 4 discs are
> needed to make each 1 disc of data for the archive.
>
> For those of you that are responsible for collections of digital media of
> any type, do you use or recommend a system similar to this? If not, what
> would you recommend instead?
>
> The second thing I started thinking about was migration. This has been
> discussed on the list before. At some point, either the media will expire
> or the technology will change, so the data has to be migrated. Now, the
> article above indicates a general need to migrate data within 5-10
> years. Do you agree that this would be necessary in so short a time,
> assuming the media doesn't fail? How do you plan a budget and logistics
> for that? If you are building a new archive, do you start doing
> migrations
> as soon as you finish the original conversions, and just keep working on
> it
> forever, always migrating? That's the way they paint the golden gate
> bridge. They start painting. It takes a year to finish. Then they start
> again.
>
> Here's something else that occurred to me about migration. I'll make an
> analogy from car maintenance (bear with me). I have an SUV. Each tire
> costs $180 or so to replace. When they all wear out at about the same
> time, that's a $720 repair bill. Ouch! Now, consider a media archive of
> 10,000 tapes, discs, or whatever. The number is arbitrary. I'm assuming
> technological change is somewhat predictable. However, what about the
> expiration of the media? Suppose the error rate found during testing on
> the media exceeds a safe threshold in 7 years, even though the storage
> technology is still viable. It's likely that all the media will start
> approaching failure around the same time, just like my tires. Suppose you
> had to suddenly migrate 10,000 pieces of media when you didn't expect
> to. How do you plan for that as well?
>
> Finally, the article talks about Digital Mass Storage Systems as an
> alternative to CD's and DVD's. What has been your experience with such
> systems, if you use them? Can anyone recommend specific systems or
> features?
>
> Sincerely,
>
> Ron
>
> ------------------------------
> Ron Frazier -- P.O. Box 2284 -- Cumming, GA 30028 -- 770-205-9422
> (O) -- 404-431-5472 (C)
> Email: rwfrazier AT macdatasecurity DOT com (replace the AT and DOT by
> hand)
> I am an independent consultant interested in exploring ways to archive
> data
> over long periods of time.
> Recordable DVD's & CD's can fail in 2-5 years. Don't let that happen to
> YOUR data.
> Get your GOLD Archival Grade DVD's & CD's from
> http://macdatasecurity.com/ today!
> http://c3energy.com/ --- http://c3energy.com/alt_energy/
> http://c3energy.com/computersecurity/ --- http://c3energy.com/health/
>
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