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CDs, DVDs Eyed For Long-Term Archival Use
Alien54 writes "Computer scientists at the National Institute of Standards and Technology (NIST) are launching an effort to develop specifications for 'archival quality' CD and DVD media that agencies could use to ensure the procurement of sufficiently robust media for their long-term archiving needs (i.e., 50 years and longer). See the press release at the NIST site." The research involves "...enclosed chambers that use temperature and humidity changes to artificially age the media some 20 years in only six weeks."
Age 20 years in 3 months.
That's what waking up at 3:00 in the morning every day to take care of the kid does to you.
A link to where volunteers can submit Celine Dion, Westlife and New Kids On The Block cds to be included for testing would be greatly appreciated
Wenn ist das Nunstueck git und Slotermeyer? Ja! Beiherhund das Oder die Flipperwaldt gersput.
Are they still working?
Honestly,
I've got CDs that I burned just 2 years ago, and my CD drive has trouble reading them - no scratches, it just appears that they age waaaay to quick. I know a lot of people who keep photos on CD, I hope they realise that it's not so permanent.
Maybe something good would come of this. I'd actually be willing to pay out $5 to $10 to get a CD that once burned would stick around for a while.
tom-george.comBecause geeks rate higher t
...enclosed chambers that use temperature and humidity changes to artificially age the media some 20 years in only six weeks.
Temperature and humidity are definitely not the worst enemies of my CDs. My friends are.
It's cool to create media that can hold information for an extended period of time. But - do not forget that you need to have a device that can read the media. I've saved some of my earliest work from the 70's on a paper strip with holes in it, and from the 80's on a 12" floppy disk. Both look like mint condition, and I'm sure they work. But - I haven't got any hardware that can read them.
So - if you plan to store digital information for decades, you need to store the player as well. That means, you need to make hardware that will work after, say, 100 years. This makes me think if we should strive after something that's human readable (microfilm or plain old paper) instead of something that require a computer. This is by far an easy problem to solve. My humble suggestion is to save information on todays media and prepare to copy it to a new media every 10 years.
For this, WORM's have been invented. Currently at 9.2 GB per media, put larger versions are in the pipeline. They are still readable 10 years after, and have been guaranteed to be readable for 100 years, given the software exists.
Just you can't burn them with your run-of-the-mill software, you need some professional software for the whole document and jukebox managment as well, else you'll have some problems to find you archived data in a decade or so when the audit comes.
Sounds like my brother's record collection just before he moved out of the basement. I could lend him a CD for a week and, if I ever saw it again, it had mysteriously accumulated a decade's worth of wear and tear.
The only sure way to archive data is to keep it on a network-attached device - and migrate it regularly with changes in technology. No removable media is foolproof as hardware can break down at a time when it can't be repaired or replaced. Ask anyone with a Betamax video collection or, more relevantly, the BBC, who had great trouble reading their not-very-old Domesday archive on laserdisc. BTW, that's not a really small computer in the photo, it's a really big CD!
When I am king, you will be first against the wall.
50 years is not long, 500 years is what we should be talking about.
Books, if looked after properly, last for centuries. OK: many modern paperbacks are printed on paper that has not been properly stabilised (still contain acid), but there are plenty of very old books.
In case you think that I am over the top: have you never looked at an old family album with pictures going back to the start of the last century? What will future generations think of us if none of that sort of material survives because we had the lack of foresight to put it onto good media?
Ok that method will take care of the plastic, but what about the embeded data layer? Will that get the effects of the increased ageing?
Always going forward, 'cause we can't find reverse.
There's a number of CDs which have already experienced 10 years of mistreatements, I wonder if any mass producing company has already learned something valuable and if they modified their production accordingly. Polycarbonate-eating fungi were already mentioned here and on Nature as well. Add the aluminum layer oxidation problem and my trust on cd-r as long term storage is reaching zero. I also own a couple of 10+ years old CDs (original, shush RIAA) that don't show any surface problem, but no player I have tried can play it anymore.
Humidity? Temperature? How lame. :)
Just get the CDs to spin fast enough to make their edges reach near c speed and store the data near that edges and you're safe about aging - a year for such data will last ages for us
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
We just had a baby girl (yes, even geeks need to reproduce). So people ask "what can we bring the little gorgeous thing?" (they don't have to sit through nights of "woaAAAHHH!") I've figured that the best thing would be presents that she can open when she's old enough to appreciate them, like on her 18th birthday.
DVD players may still be around in 2021, after all I can still read 3.5" floppies. But DVD media has a shelf life of 5-7 years AFAICT, several older DVDs I've tried recently don't work anymore. CDs may be less delicate, resist better.
But if you wanted to give someone a digital present (say a bunch of their baby photos) for 18 years hence, how would you go about it?
This was going to be an Ask Slashdot, but (a) I'm too tired, and (b) the whole "what can I give a gurgling baby" thing is not really stuff that interests geeks.
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Discs in fact are way better method of storage than traditional tape storage due to ease of accessiblity. However, in order replace tape for long term archiving, more has to be done than making durable discs.
:). I do not know exactly how but they must have something to charge us enoromous amount of money for recovery. :)
The other major fact is Recoverability. It's not unusual to find defective tapes before their end-of-life and we must send them to experts for retrieval of important data in them. They've technologies to recover the data, like baking the tape(yeah, bake them in oven, but please don't do it with your kitchen oven
I'm not sure if existing technology could effectively recover data from aged, defective discs. That's something we must consider before they could replace traditional tape storage for long term archiving.
What I meant to say, is:
You write to whatever media is in vogue, and then periodically you read it back, checksum it to make sure it's not corrupted, then write it back again to a new media. Repeat ad nauseum.
Now imagine you've got to do this for whole applications and infrastructures to support those applications, and have them instantly viewable by the FDA at any point over a 25 year period.
This is what working in pharamceutical IS is like.
It shows that digital still has a long way to go compared to the current UK practice of printing on vellum... in other words goats skin !!!
Quote: "... we compare longevity of 250 or 500 years [of long-life paper] with the 1,500 years of vellum"
---- The Open Source Record Label : : LOCARECORDS.COM
They tested 30 different brands of CD that had been recorded only 20 months earlier. Here is a picture of one of the CDs.
The red area can no longer be read.
This is pretty hideous.
I use CDs for archival storage.
It looks like it will become necessary to copy everything to new media every year or so, lest it become lost, forever lost, never to be seen again by the eys of mortal man.
It's very annoying.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
For a start.
A typical backup tape will handle 120Gb to 200Gb these days.
Then you have the problem with getting hardware which will read the disks in 20 years or 50 years.
The real solution to archiving is the ability to move to new formats as they appear and become cheaper than the existing technology, it's an ongoing process, not a product. The hardware itself should be irrelevant.
Government of the people, by corporate executives, for corporate profits.
Yes I still have some CD's and a few of them are from the 80's.
I couldn't tell you if they work or not, because all the music I play is in MP3 format.
Why look for a 50 year solution, when in 20 years the archives will be stored on more efficient media, just like mp3's.
thank God the internet isn't a human right.
I understand that removable media always run a much greater risk of going bad as they're exhibited to all sorts of possibly harmful effects. However, I'd really like to see "CD-like" discs that last at least for around 20 years to give us plenty of time to at least transfer them to more modern media when they arrive. The problem right now is pretty bad since the media degrades much quicker than new technology arrives, with CD's already becoming unreadable when we haven't even fully made the switch to DVD's yet. I'm sure there are other perhaps more reliable removable media available, but they aren't as widely accepted, and I find the problem actually rather silly since reliability on removable media should come as a top priority, with those often being used exactly for storing old data not immediately needed on a hard drive -- as an archival media.
:-P
If this test will lead to an insight in making more reliable CD's or DVD's, where those can be somehow certified with a special "Archival Quality" tag, I'm sure they would sell a lot even to a greater price. I'd completely switch to them at least, since I burn CD's to make them last for a longer time than a year or two. Switching to tapes or something like that isn't very useful, since everyone I might bring my CD's to would need a tape drive.
Beware: In C++, your friends can see your privates!
If you're a sysadmin, this problem has already been solved. RAIDed hard drives, always on, read occasionally to check for errors, and drives replaced as they fail. Replace the drives with new models every so often (or as they fail perhaps). Replace the controller and system it is attached to as necessary.
That is to say, that no digital storage that exists outside of a lab is suitable for long-term archival. Luckily, digital data being so easily copied (how easily people forget this!) makes this an easy problem to ignore. If you're developing new types of media, great. Otherwise, there is only one practical solution.
Yes, "my" solution - the solution used by anyone who has digital data they want to store long-term - requires someone to babysit the data. Sorry, most things in this world need some kind of human maintenance.
If you're storing the data on hard drives attached to a working computer, you can mirror the data on the other side of the world to protect it against any catastrophe that humans will survive.
If you don't care about a practical solution that has by far the highest chances of success, feel free to speculate about how long CDs will last based on completely invalid lab testing. (Accelerated aging? Hah! How can they possibly account for every variable?) If you truly care about your data, keep it online and make sure someone is around to maintain the system. If you want something less, it's because you don't actually care about the data that much.
Kodak did some accelerated longevity tests on CD-Rs and found that many disks degraded rapidly when exposed to sunlight, due to the UV components of sunlight.
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It looks like it will become necessary to copy everything to new media every year or so...
A common mistake is that archives (digital or otherwise) require no maintenance. In the case of digital archives you should be checking them, on an annual basis, not just for physical degradation.
A more common problem is that the applications used to create the data and/or their documentation do not exist any more, rendering the data as useless as if the physical media had been destroyed.
--
This sig is inoffensive.
On the other hand, I'm also a bit concerned with privacy, and the idea of these huge intrusive databases, or archival of all traffic over key gateways of the net bother me. But when I consider the difficulty that I have with huge amounts of data that are just a drop in the bucket conpared with this sort of thing, I breathe a little easier... Unfortunately, duplication and propogation appear to be the surest way to go, and unfortunately there is often a tendency for those who would invade our privacy to share their data for profit or reasons of control...
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Magnetic tapes leak, don't they? I have a pack of cassettes recorded with old stuff I wrote for a C64, 20-odd years ago, and even ten years ago they were already unreadable. This was not even high-density recording, just normal screeching. My understanding is that each layer of tape has a small effect on its neighbours, and after some time the entire tape is reprogrammed to noise. Presmably if the tapes are played and rewound the effect is less dramatic.
But magnetic tapes do not strike me as particularly stable. Hard disks may be more stable than tapes.
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This effectively exists already. Recordable CD/DVD longevity is largely a function of dye stability. Over-generalizing, modern media support higher-speed writing because the dye is more stable. Ergo, greater long-term stability.
Unbranded media have other problems, in that frequently they're low-speed disks marked up as high-speed, so they get prematurely aged as they're written to.
Although I've got a couple of old CD-Rs that are unreadable, my MO stuff going back to 1989 still seems to be OK. So is my old PD stuff. Maybe phase-change is the way to go.
In 296,000 years Voyager-2 will pass Sirius... Do you think the gold video disc on-board will still be readable? :-)
"You lied to me! There is a Swansea!"
one way to preserve data longer than 50 years is still microfilm. Guaranteed to las at least 100 years, if processed and stored correctly. Currently several companies offer the service to store 'digital dots' on microfilm, instead of typeface, improving the data-density considerably. Of course density is still waaaay below that of DVD or CD, but at least you're sure it'l be there in the future, and relatively easy to read (optical-scanning...)
Some things I've discovered so far are:
The biggest problems seems to be that the CDs come and go, so it can be difficult to get the tested products. The tests that has been done has used "accelerated aging", which is just a simulation. That is, there is no real experience in aging CDs.
My advice would be to store valuable information on as many different formats as possible. Continually monitor the quality of these, and transfer to new backups when they start to degrade too much.
Hope this helps!
And acid free paper doesn't turn to ash.
The RIAA must be ROTFLTAO at the thought that the plastic they sell is a perishable good. Only slightly (take the long view, some books are hundreds of years old,) more perishable that the original source which only lasts as long as an echo.
I have vinyl from the '60s and '70s that I played on a good turntable then and (since I still have that turn table,) I can still listen to now.
Since the early 20th century, our industrial processes have been destroying our heritage.
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Considering the relatively short life expectancy of digital media, the DMCA, and the extensions to copyright term over the past few decades, imagine the Dark Age our children and grandchildren will be facing 50-100 years from now. Only the memories of old men and women and the loot of "pirates" will be available to help fill in the great blank space in our cultural history.
Age 20 years in 3 months.
Dude, reverse that process and you've got a winner.
The coolest voice ever.
I see a lot of people saying that the short CD lifespan is not a problem .. you just copy from one generation of media to the next as you approach the optimum time.
Well that doesn't really cut it for two main reasons
1/ You have now decided that the only information you will hand down to the future is that the stuff that you care about now. As soon as you stop caring about that data, or your descendants stop caring, then that data will lost.
2/ It will only need a skip of roughly 2 generations of technology before you won't be able to recover any digital data that you (or someone else) accidently re-discovers.
If this doesn't seem important, look at what historians and archeologists are finding/learning from poking around things that have survived millenia, compared with the despair of knowing what huge gaps exists from records/items that have been irretrievably lost.
So how do you want to judge the concept of "archival"? As something that is accessible as long as the item is whole, or as something that requires active intervention to maintain its integrity?
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30 years is considered good enough for day to day use, nowadays. But as a teacher of mine keeps repeating: "we have more problems retrieving data from the 1970's than from the beginnig of this century" Indeed, our future generation will only see a gap...
The difficulty is that these disks cost a dollar or two each. Compare this with the el-cheapo ones that sell by the billions. Few mass consumers bought the good CD's, and Kodak stopped making them entirely and the Mitsui's are now specialty products that are not widely available.
There's also been a major shift in where and how CD-R's are manufactured. At first they were high-spec products, made in a few select factories in the US and Japan. Then manufacturing scaled up and cheaped out as the plants moved to Taiwan. Now a lot of those plants are going even lower-budget and moving to Mexico and mainland China.
The point is that consumers rarely buy for longevity... they go for neat packaging or cheap price or high burn speed or something else. The CD manufacturers have learned that lesson well. That's why it's so hard to buy good archival CD-R's anymore.
But CDs are an interesting case. You could argue that, unless we lapse into complete barbarism or some rejection of science, recovering old CDs should be possible for any future civilisation if the bit pattern is preserved. Provided the encoding and protocols are stored safely somewhere, it should be possible to construct a reader if anything is considered important enough to read. Unlike tape or punch card, the mechanical handling needed for a CD reader is very simple. Small lasers are made in ever greater volumes, and anything that replaces them is going to be more, not less capable. They use little power and there is no environmental reason why they are likely to fall into disuse.
Even so, my best photos are printed on archival grade non-resin coated acid free stock that should last a couple of hundred years. As if anyone is likely to care.
Panurge has posted for the last time. Thanks for the positive moderations.
Why not archive on a high-quality film?
If documents are important to archive, especially for long periods of time, transferring the data to a less technical medium such as film is a much better alternative to the CD.
20 years ago, a great many people owned 8-Track tapes and players, along with record albums on vinyl. Very few of these items are readily available. I certainly know a few people with turn tables, but no one who owns an 8-Track player.
Whos is going to gurantee that the technology in use in 2103 can read a CD created in 2003? By storing data on film, even as a series of light/dark bits, requires very little technology for retrieval. Think about that, a lamp, a lense, and a wall to view an image. Data encoded as a string of bits could easily be read into a recording device.
Many types of film can be stored for much longe periods than CD's, and can be easily copied and in some cases restored.
Why does no one take a Tyrant like approach to this problem?
Actually, a glass master is a physical object... it's a glass disc etched with the negative "cast," which is pressed into the polycarbonate layer to form the pits and lands of the CD during manufacturing.
A glass master is very fragile, fairly expensive to make (~$500 depending on the pressing plant), and obviously won't play in your CD player. ;-)
Many people have talked about older methods of storage as the gold standard. Paper, vellum, papryrus, clay tablets - some documents written on these media have survived thousands of years.
BUT, they have not survived that amount of time without degradation. The reason we can still read them is because of their low information density. Documents can fade - a 1 inch square portion of a document could flake away, leaving the original text still readable. Why? Because 1 square inch of most documents doesn't contain all that much information.
As physical objects I suspect that quality CDs or DVDs would degrade less over 1000 years than just about any of the other media I've previously mentionned. The problem is that we are trying to cram so much data onto them that even the slightest bit of degradation leads to data loss.
So what's the answer? Massive redundancy. Replicate data in 100 different ways across the surfaces of the CD or DVD - this might dramatically decrease the storage capacity, but even 10 MB on the surface area of a CD is a massive improvement over the storage density of vellum. Now you have a chance of lasting 1000 years. Even if the CD is shattered and all some future archeologist can find is a shard, there is a good chance that the entire data set is contained within that shard, perhaps even multiple copies.
Even further, one could imagine using file formats that are resistant to file errors, perhaps uncompressed raster images. Easy for future scientists to decode, and wonderfully resistant to degradation. This is just another way to decrease density.
-josh
Wow! I wonder if I can get one of these for my wine cellar.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
What good is archival quality media, if you don't have the device to read it with?
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Once I accumulated 5 years worth of backups, I copy the expiring data to new media and throw the old away, this gives me a little protection from 1) aging media and 2) aging i/o devices. I also make sure that as I get rid of older devices, that I convert all backups it might use before getting rid of the device.
Simple, but it works well for me.
I think it's even more hideous with the advent of digital cameras. How many people in this world are keeping their children's memories on a disc because it's cheaper than standard film or cheaper than printing out the digital photos? How many people will find out in 10 years that they have zero pictures of the children as babies? As a parent, that's a a very scary thought.
With that said, I always thought DVD-R for Authoring were supposed to be the big bad media that was made for archiving data. Granted that's not a CD-R, but I was under the impression that at least some optical format existed for "consumer" use (it's pretty expensive for the drives right now). Anyone well versed with optical media care to comment?
Also, I have compact discs that are pushing 15 years old that play just fine in my car, computer and home CD player. Is it not possible to make this kind of durable media available to the public?
When I read the previous slashdot post about CDRs rapidly decaying (even becoming unreadable in a few years) I had trouble believing this... but I ran my own tests using the "Nero CD Speed" tool's ScanDisc option.
What I found was that my 3 to 4 year old archival CDs had anywhere between 20% to 50% of their surface damaged; they had (recoverable) errors. This spanned multiple brands, including Memorex, Acer, and HP.
Remember that data correction algorithms can recover from minor errors, but if data is becoming damaged this quickly it will be not too long before data is actually lost on CDRs.
The problem :
:
A paper based collection of 100,000+ maps dating back to 1886 that are slowly decaying with use. They require digitisation for long term ( 200 years +, at least as long again as they have survived already ) archiving but need to be available quickly and easily for viewing on demand. Total storage requirement is in excess of 150 Tb.
The Solution
An archiving setup using Magneto Optical technology in managed jukeboxes in a controlled environment. MO has been around for nearly 20 years now and is a highly refined and proven technology. Current capacities are up to 9.1 Gb per media item with 30Gb coming online in the near future. Jukeboxes handling up to 10Tb per unit are readily available now.
MO doesnt use dye at all. The laser melts a magnetic substrate that is then manipulated by the write head to impart the data in a similar way to a conventional disk, the sustrate cools and the data is permanantly stored. There is no degradation of the media by sunlight, heat etc as compared to DVD or CD formats. It's more accessable and requires less management than tape, its cheaper than conventional disk, off site storage of duplicate media is easily achieved, data throughputs are faster then DVD or CD and capacity is as good or better than either.
Is there any reason you couldn't design a "book" that would actaully be a machine-readable optically scanned card deck. You'd get the advantages of a durable paper stock, and the decks could be bound in such a way that they could be mechnically unbound, read, and returned in the way similar to a tape library.
I'm not sure what kind of data density you could get, though, although I suspect it would be slightly more than you might think. It creates a storage problem, but then it has great durability, and the machine to read it would arguably be easier to re-make in the future than the ones used to read traditional optical media, since you could include a card in each deck explaining in human terms how the deck is encoded.
The MAM-E (former Mitsui) Gold Archive and Verbatim Datalife Plus are the best CD/DVD blanks you can get in terms of longevity. In general, these brands along with TDK are what I recommend to folks almost exclusively because they have the best quality control. I've heard good things about Taiyo-Yuden and Mitsubishi's high-end blanks as well. Sadly, Kodak Gold blanks are no longer made, but if you can find some, go nuts on them.
Longevity is the last thing that people are thinking about. That's why crap blanks like Princo and Memorex are usually the best deal price-wise. Whether it's your music collection or home videos, you can't afford the cheap blanks. Of course, I also recommend many of the same things that the original poster (environmentally controlled environment isolated from light). However, using CDs with less storage space really doesn't make a big difference if you've temperature controlled them. The size of the "bits" is not going to be the deciding factor when there's already in-line error correction and redundancy. Just use good archival blanks.
One last note...for the truly paranoid, you should actually go and get a CD mastered by a manufacturing house that specializes in this type of thing. This may not be the cheapest option (probably on the order of hundreds of dollars), but what's your data really worth if you lose it and can't get it back?
My oldest CD-R is from 7 Oct 1996. I just copied its entire contents to my hard drive without encountering any errors, so it *appears* to be entirely readable. The CD-R is a Verbatim "DataLifePlus" CD-R, and it is dark blue. The contents were burnt at 1x speed. The contents are only 250 Mbytes, so it is not close to full.
These pits aren't likely to degrade for some time.
In contrast, any current CD-R/RW of which I am aware stores information photochemically; i.e., the information is stored in a dye that changes state due to the application of light from a laser beam.
These chemicals are likely to degrade much more quickly than are physical pits.
I don't believe that this situation will change any time soon.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
The idea that name brand does not imply quality in the CD-R market is quite correct. There are only something like 14 companies in the world that make CD-Rs but there are hundreds of brands out there that buy and then resell them under their own name.
So therefore it's important to know which company manufactured the disc as opposed to which is selling it. It's also important to know that some name brands buy from more than one manufacturer. For example, my 'archival' burning is done on FujiFilm discs made by Taiyo-Yuden, one of the best manufacturers. But I have to be careful because Fuji also sells Ricoh media. Typically the "Made in Japan" mark identifies Fujis that are from Taiyo-Yuden. This is how I find the quality.
So how do you tell if some disc on the shelf is good or not? Buy a single disc, bring it home and use an ATIP-reader utility to find the manufacturer name. If it's a good manufacturer (i.e. a manufacturer you have carefully researched and is known to make very good CD-Rs) then go back and buy a truckload. Otherwise keep searching.