I don't even try to use optical any more. The image of cast-in-bronze was emotionally appealing 10 years ago, but a big part of successful archiving is being able to move a lot of data regularly, and the 8.5 GB limitation of a DVD-DL makes that too cumbersome. Therefore, I find using SATA drives as backups and then storing them offline (unconnected and unpowered) is a good way of storing up to 2 TB on a single medium. Another part of the trick is to regularly upgrade your on-line drives in size so that data is regularly copied onto newer and larger media. Migrating all your data every year or two to a new device might seem like a gigantic pain, but it "stirs the bits" and keeps them alive. As an added benefit, you have a defacto backup on your old retired drive.
(Not an I.T. guy) -rei On 06/02/2010 01:37 PM, Snoopy wrote:
Indeed - I have about 800 CDs and of those three ave started to get "bit-decay". You can see the coating flaking off INSIDE the CD. I always kept them away from sunlight etc. I am aware of diefferent processes: that's why I thoght the "pressed" ones wold last longer as they are not chemically recorded but the pits are actual physical dimples. But then there were also some pens marketed for "Cd marking" whose ink ate through the top protective layer and destroyed the coatng within. Bad news. Thats why a lot of archives now record digital data as dots on microfiche...and store the films in huge salt stocks under Nitrogen etc. Love, Snoopy Tim Daneliuk wrote:On 6/2/2010 10:54 AM, Dana Myers wrote:On 6/2/2010 1:48 AM, Snoopy wrote:Recently German TV showed a documentary about the Central Music Archives in Berlin which has problems with storing music CDs etc. They report a life span of about 5 years and copy everything all over the place to make sure they do not lose things.As an aside: That's hardly representative of the permanence of CDs. I was a fairly early adopter of music CD in 1985, I have over 100 CDs that are well over 20 years old with no apparent deterioration. I do nothing special to store them. With that said, relying on the integrity of a single piece of media for long-term retention is not a good idea - the ability to produce exact duplicates with no loss of quality is critical to a long-term archival strategy. Cheers, DanaI too have 20+ yo CDs that are just fine. However, and for the record, it should be noted that factory produced music CDs use a somewhat different process than the dye-based burn used on your PC. I'm not suggesting one is better than the other, merely that their archival behavior will be different in all probability.
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