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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.
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
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.
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?
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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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.
Would you really want them to find out how to make CD's of Celine Dion, Westlife and NKotB last a hundred years?
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.
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.
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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!"
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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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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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.
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
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.