If you believe the information found on DVD packaging, you shouldn’t have any concerns about placing your wedding video, important business documents, family archive photos, etc. on DVDs that use gold as their reflective layer or are a little more expensive and sold under the label, “archive DVD” (a bit of an oxymoron really… keep reading). You wouldn’t have any concerns about using such DVDs for long-term storage since their packages are emblazoned with claims of ten, twenty, fifty and even one-hundred -year life expectancy. You’d sleep well knowing your fondest, most important memories and information are securely preserved.

So why are people who make a living from storing crucial, one-of-a-kind digital data not following your lead? What’s keeping librarians, archivists, photographers and genealogists from running down the same path for their long-term storage needs? The best answer may be found in a presentation prepared by the Memory of the World Programme’s Sub-Committee on Technology. This provides detailed guidance on assessing the risks associated with storing archival data on recordable CDs and DVDs.

Here are some of the warnings from the document that consumers will be well-advised to heed as they run contrary to what manufacturers and marketers of recordable DVDs have been telling us:

1. (Preface) Around [the year] 2000 … Concerns about the reliability of recordable CDs and DVDs were also supported by an increasing number of reports of discs failing at the time of their production.
2. (Preface) … and while several products have been marketed since which attempt to optimise their longevity, the principle problem remained unsolved.
3. (Introduction) Even though subsequent technological development has improved on many of the early manufacturing faults no credible claim can be made to permanence.
4. (Introduction) Recordable CDs and DVDs are often chosen as archival carriers, however, the risk of failure of a storage system based on this type technology is high when compared to other approaches.
5. (Page 10) Error measurement is a critical part of producing reliable data on a recordable disc. The fact that the data is able to be read, as assessed by “verification”, is not sufficient indication on its own because a disc with a high level of errors can sometimes still be read, but is very likely to fail soon after.
6. (Page 10) Dye type, though significant, is only one of the factors determining the life of the media. The variation in the amount of dye used in the dye layer, a result of the manufacturers’ race for even higher recording speeds and higher density recording, is a contributing factor in the long term failure of recordable optical media.
7. (Page 10 ) It should be noted that discs optimised for high speed recording use less dye, which may indicate a shorter life expectancy. DVD-R uses less dye as a matter of course, as the data rate when writing to a recordable DVD is much higher than for CD-R.
8. (Page 11) Many discs that appear to be reputable brands may turn out to have been manufactured by a second party and repackaged for sale.
9. (Page 13) The error correction capability of most replay equipment will mask the effects of degradation until the errors are well into the uncorrectable region. When this point is reached, all subsequent copies are irreversibly flawed.
10. (Page 15) The use of recordable and rewritable CD/DVDs as archival carriers cannot be advocated unless a strict testing and monitoring program is set up. It should be noted that testing and analysing, though absolutely necessary, will be time consuming, adding long-term costs to the archival solution. When planning an archival strategy, these costs should be included.
11. (Conclusion) Recordable CDs and more recently DVDs are very popular storage media. Because of the relative simplicity of their production, their easy availability and their financial affordability they have been very frequently used in projects to preserve and make accessible cultural and scientific documents of all kinds. As they were never intended for use as reliable media for long term preservation and have been developed primarily as a consumer product for the mass market their use in critical archival and preservation contexts constitutes a significant risk.

This document was revisited by the Sub-Committee in 2008 and found to continue to be relevant and useful.

CD/DVD experiential life expectancy is 2 to 5 years even though published life expectancies are often cited as 10 years, 25 years, or longer. However, a variety of factors discussed in the sources cited in FAQ 15, below, may result in a much shorter life span for CDs/DVDs. Life expectancies are statistically based; any specific medium may experience a critical failure before its life expectancy is reached. Additionally, the quality of your storage environment may increase or decrease the life expectancy of the media. We recommend testing your media at least every two years to assure your records are still readable.

From The U.S. National Archives and Records Administration Web site (Item 6 in the FAQs)

Who knew? Certainly I didn’t. For some time now, DVDR manufacturers have been leading us to believe that by replacing the silver reflective layer with gold, they have somehow increased the life-span of your data on their DVDR discs. Most of us really don’t have the time to dig into the technology behind optical storage media to know if that premise makes sense. The discs cost more, come with a claim of preserving your files for 80 to 100 years so what’s there to doubt?

Unfortunately, there are many things about DVDRs that can be considered weak points in the design. Any one of these weak points can easily and silently put your important files in jeopardy. Most notably:

1. when silver was used as the reflective layer, it was prone to oxidizing which defeated its ability to reflect. This problem was solved for conventional disc design by replacing silver with gold.
2. your data is stored on a layer of organic dye as it reacts to the laser beam when the disc is burned. This dye, being of an organic nature, breaks down even in the best of conditions. It is very susceptable to exposure to light and temperature.
3. the beam used to burn the data onto the dye layer is also used to read the data back, causing additional degradation of the data layer every time the disc is read.

Recently, people have begun going to their DVDR archives to access their important files and are discovering this unexpected data loss. A writer for the New York Times told of his experience and people commented in droves about their experiences as well.

Feel free to share your experiences in the comments here.

What happens to a picture with data loss.

It was late 2005 and I had just finished a meal with Jeff Barr at what used to be one of my favorite restaurants in Bellingham, the Big Fat Fish Company.  Why that establishment used to be my favorite is a topic for an entirely different blog post.

As we were leaving I asked Jeff what kind of digital camera he used. What I’d hoped would be a quick recommendation for a replacement camera turned out to be an eye opening experience.  Jeff said he didn’t like the concept of digital pictures and digital video because he didn’t know of any viable way to store digital files for the long term.

What?  Nobody told me that. I’d been using a digital camera for years. Was he saying that all of my pictures were in jeopardy?  Turns out that’s exactly what he was saying. Jeff works for Amazon as a technology evangelist and is a pretty credible guy in my book.  I paid close attention and felt compelled to do some research of my own.

I already had a sense that hard drives were problematic since I’d experienced several platter collapses or other hard drive failures in my life.  I also knew that hard drives had the additional problem of being a magnetic media. (Those of us who can remember cassette tapes and VHS know how poor magnetic media is for long term storage and playback.)  I learned that USB drives and memory cards only had a limited number of read/write cycles.

What about online storage?  In theory, storing files across the internet on redundant systems seems like a good idea, and until recently it appeared to be the only real solution for long-term storage. The problems associated with online storage is fodder for a future post. Let’s just say it did not meet my criteria for permanent storage.

My search led to a solution that will outlast my requirements, perhaps keeping my information safe for centuries. I understand that I probably don’t need my files to last that long, but I do need them to hold out until another viable permanent solution is available.

The answer came from a smart group of professors at Brigham Young University in Provo, Utah (more on this later), and I ultimately invested in the company that licensed the technology from BYU. Right from the beginning I could see that the company was hyper-focused on the enterprise and government markets.

But I wanted access to this for the public’s personal use.  My company, Humanicity, operating under the name “Cranberry,” has since secured the exclusive rights to this new technology for the consumer marketplace. Now, people like you and I can use this state-of-the-art digital media storage.

And it all started with a simple question over dinner with a friend.

Need more information?  Stay tuned to this blog or the Cranberry Web site for more details as we get closer to our public release of the Cranberry DiamonDisc™.