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DC DSL
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reply to pandora

Re: What happend to 2.88MB Floppy Disk's

said by pandora:

said by DC DSL:

You clearly did not understand what I was talking about. *Permanently unmodifiable* does not have anything do with longevity of the medium.

I assume if previously readable data becomes unreadable, it has been modified.

You're treading dangerously close to troll territory there.
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2 edits
said by DC DSL:

said by pandora:

said by DC DSL:

You clearly did not understand what I was talking about. *Permanently unmodifiable* does not have anything do with longevity of the medium.

I assume if previously readable data becomes unreadable, it has been modified.

You're treading dangerously close to troll territory there.

Media degradation modifies content. I don't think there is a dispute about this. When I searched, burned DVD's may have a readable life of between 2-5 years depending on the products used and storage.

I would not assume burned DVD's are secure to hold data for 7 to 10 years, mostly due to degradation of the media. It is true a USB device is easy to modify, but my belief is degradation also modifies data. The intent is to point out at a consumer level, we don't have very good choices.

There is no trolling here. Just pointing out that we can't assume long term viability of just about any PC storage media.

I would point you here »www.pcworld.com/article/124312/article.html -

"Unlike pressed original CDs, burned CDs have a relatively short life span of between two to five years, depending on the quality of the CD," Gerecke says. "There are a few things you can do to extend the life of a burned CD, like keeping the disc in a cool, dark space, but not a whole lot more."

The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam.

"Many of the cheap burnable CDs available at discount stores have a life span of around two years," Gerecke says. "Some of the better-quality discs offer a longer life span, of a maximum of five years."

Distinguishing high-quality burnable CDs from low-quality discs is difficult, he says, because few vendors use life span as a selling point.

As to editing a read only drive ... I assume somewhere someone is able to modify firmware / software to try and modify data on a burnable (writeable via laser on a CD / DVD burner) closed disk marked as read only. Assuming the existing media is write only, I wonder if data destruction of supposed read only DVD's isn't possible. It's never been anything of a concern to me, but to assume someone couldn't write all one's to existing disk would seem to be a bit optimistic. Not that the data itself would be modified, just new data added to the existing could render the media unreadable.

Doing a quick search, I came across this - »www.ehow.com/how_7442372_erase-c···d_r.html

DVD-R or DVD-RAM discs work well for storing large files such as movies and backup files. Unlike rewritable DVD discs, DVD-R discs typically are suitable for burning information a single time. However, you may be able to delete items from a DVD-R disc, if necessary. Check the product specifications supplied with the disc before performing these steps to determine if erasing files will render the disc unusable.

Read more: How to Erase a DVD-R Disc | eHow.com »www.ehow.com/how_7271603_erase-d···FKB0RFi4

We may just have different perspectives about the long term viability of any storage media. I started with IT when punched cards and very large tapes were used to store data. A punched card reader would be hard to find, as would the old 360 era tape drive readers. Connecting an old tape drive using the IBM channel bus, could be problematic as well. Each tape drive required a controller. My experience with computers runs over 40 years. I've seen a lot of change.

Edit: Thinking about it, my first experience with data storage was on something called a Friden Flexowriter which used long strips of paper that was punched then later read. This was prior to my use of punch cards in college. Imagine trying to find a reader for that data today?
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DC DSL
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Just give up. You went off on a tangent that had NOTHING to do with the point I made. Media degradation is not the point. If you knew anything of the subject I referred to, you would know that there are requirements for ensuring perpetuity of certain types of historical data. Instead, you want to ignore the fact that you contributed nothing relevant and hope that you can bamboozle everyone else into believing it as well. No. You do not get to do that.
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rolfp

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reply to pandora
said by pandora:

When I searched, burned DVD's may have a readable life of between 2-5 years depending on the products used and storage.

Maybe something new:

said by berserken, here :

I've never trusted optical media for long-term storage.

There's something new (to me, at least) that promises long life in an optical disk.

M-DISK




Overview
The M-DISC utilizes chemically stable and heat-resistant materials that are not used in any other DVD or optical disc! These materials cannot be overwritten, erased, or corrupted by natural processes. Data is stored on the M-DISC by physically altering the data layer and creating permanent voids or holes. This new method of burning data is specifically designed to make your data endure the next 1000 years.


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reply to DC DSL
said by DC DSL:

Just give up.

No tangent. Just a different point of view. No need to insult anyone. We have no viable long term data storage technology imo for PC's at this time as the hardware the media requires tends to not live longer than 20 years, and the a lot of the media used (particularly burned DVD / CD's ) may not have a shelf life as long as the hardware used to burn it.

Please stop insulting me personally. Thanks.

As to 2.88 mb floppy drives, the expression a day late and a dollar short comes to mind. »idioms.thefreedictionary.com/day···ar+short
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"


Cheese
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reply to pandora
According to the "Care and Handling Guide for the Preservation of CDs and DVDs - A joint Council on Library and Information Resources (CLIR) and NIST project" guide,

"Among the manufacturers that have done testing, there is consensus that, under recommended storage conditions, CD-R, DVD-R, and DVD+R discs should have a life expectancy of 100 to 200 years or more; CD-RW, DVD-RW, DVD+RW, and DVD-RAM discs should have a life expectancy of 25 years or more. Little information is available for CD-ROM and DVD-ROM discs (including audio and video), resulting in an increased level of uncertainty for their life expectancy. Expectations vary from 20 to 100 years for these discs.

"Few, if any, life expectancy reports for these discs have been published
by independent laboratories. An accelerated aging study at NIST estimated the life expectancy of one type of DVD-R for authoring disc to be 30 years if stored at 25°C (77°F) and 50% relative humidity. This testing for R discs is in the preliminary stages, and much more needs to be done."

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reply to rolfp
THAT is interesting, thanks. For long term storage, any user, particularly companies, hospitals or government has to think not only about the media itself, and media storage (not too hot, not too cold, etc) but also the viability of long term devices to read media.
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"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"


urbanriot
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I store my archival discs vertically, as recommended, in the appropriate environmental conditions and my archived discs from the 90's are starting to degrade. Most of my discs from 1994, created with Kodak 'lifetime' discs, are exhibiting media read errors.

Many of my no-name discs from the late 90's and early 00's are a complete write-off (but I knew that buying them at the time).

I've had good luck with Verbatim DVD+R's standing the (limited) test of time I've been using them, since the mid 00's.

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2 edits
reply to Cheese
Hi,
As best I can determine, the 100 and 200 year life expectancy of CD and DVD media report by NIST was published as NIST Special Publication 500-263 a PDF summary is online here - »www.nist.gov/customcf/get_pdf.cf···d=150372

There were a half dozen methodologies used to produce rapid aging, and about 10 test methodologies to test the consequence of aging. The project detail indicates all work stopped after 2006, and the results were not only incomplete but there were breakdowns of equipment and many assumptions made about the failure and its effect on the analysis being performed.

IMO the report is incomplete, testing stopped in 2006, and was never resumed. Several testing machines broke, how that affected testing wasn't investigated. Looking at the NIST spreadsheet data, there seem more questions than answers regarding the production of the report or why testing was never finished (which is unanswered to the best of my searching).

Media longevity tests by the optical media industry (and at least one of the NIST tests) seem to assume temperature as the only stress on media over time. The assumption also is made that temperature range can be controlled over the 100 to 200 year period within a few degrees. The 200 year mark can be hit using BLock Error Rate (BLER) test. Other tests produce different results. Even the 2006 NIST tests indicated very wide / unpredictable variation for the limited testing that was in progress before the plug was pulled on the project.

The international standards organization (ISO) has defined two methods of determining longevity of CD and DVD media. They are ISO 18921:2000 for CD-ROM media and ISO 18927:2002 for CD-R media.

The latter standard involves a 2 year test. How often does the same media, stay on the market, unmodified for 2 years? Production changes occur regularly. A sku may remain constant, but the dye, manufacturing process, and substrate materials may all change a lot over 2 years. At time of purchase without testing, we don't really have a "good" guess as to longevity of any particular media. We hope it'll last a long time, but we can't be certain.

A organization called Optical Disc Archive Test Committee (»www.odat.org ) was created to assess optical data longevity. They discuss the problems introduced in this thread in considerable detail. The problem for current optical, is not very different from the problem with 2.88 MB floppy technology.

The technology moves, and changes, not only the media, but the interfaces and write / read technology. Compatibility with legacy technology is not guaranteed or in many cases even practical.

Another issue brought up by a poster, regarding estimated longevity of data on media at 100 or 200 years, is the difference between a backup and an archive.

A backup, is for intermediate retrieval of something lost. An archive is for long term storage of data. Sarbanes-Oxley requires data be archived for 20 years, GLBA (aka the Gramm-Leach-Bliley Act) requires 10 years, the Patriot Act requires an archive for 20 years, HIPAA requires a 10 year archive.

Finally, I wind up at »www.archives.gov/records-mgmt/in···faq.html this is the part of our government which defines appropriate practices for data archives.

From that site I see the following -

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.

Every 2 to 5 years (the limit determined by archive.gov), data must be migrated from old CD or DVD media to new and verified, to be within the definition the government archives suggests for best practices. These standards are likely important to any company or agency that may experience litigation and be required to produce digitally archived data.

This was an interesting thread. It brought up a number of issues to think about, starting with the 2.88 mb floppy.
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reply to urbanriot
said by urbanriot:

I've had good luck with Verbatim DVD+R's standing the (limited) test of time I've been using them, since the mid 00's.

I had some circa 1995 / 1996 Microsoft pressed (not burned) CD's and was cleaning the house. Prior to tossing them, checked to see if they seemed readable. A complete test was not done as these are 1x media, but the files seemed to be there on a quick check.

I've had mixed results with some older burned DVD's, one was left out in light for a few months, and needed data recovery (it was about 6 years old). Most of the pictures stored on it were recovered, but not all. So far, that was my only bad experience with an older (6 years old) burned DVD. I do not recall the maker. At the moment I'm using Philips DVD-R.
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"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"