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The Myth Of The 100-Year CD-Rom
Toshito writes "Are we putting too much faith in the ubiquitous "recordable CD", or CD-R? A lot of manufacturer claims 100 years of shelf life for a CD-R. But in real life, it can be much less. Expect failure after only 5 years... Personnaly I just discovered 6 audio cassettes with the voice of my late grandfather, talking about old times. These tapes are copies of reel to reel recorded in 1971, and they are still in excellent shape.
I was thinking about digitizing everything, do a little noise reduction, and burning this on CD's, for my childrens and great grand-childrens enjoyment, but it seems that old analog tech from the '70 is more reliable than digital. The full story at Rense. Other links about the subject: Practical PC, Mscience, and an excellent reasearch by the Library of Congress (warning! PDF): Study of CD longevity, html version (google):Study html."
I was thinking about digitizing everything, do a little noise reduction, and burning this on CD's, for my childrens and great grand-childrens enjoyment, but it seems that old analog tech from the '70 is more reliable than digital.
Record it to your HDD in an non-lossy format and store copies of it on various friends' and family members' computers. Back up frequently and your recordings won't suffer from the kind of decay and generation loss that analog tape does.
The story about the Rot of Death seems to come up every once and a while. My fun strategies for longevity:
- If you can rub the top of a CD and have your finger come back silver, that's a bad sign. I avoid cheap CD-Rs. Sorry, CompUSA.
- I burn at 2x, always, unless I am burning something that I don't care about. Someone showed me the difference in color, I was convinced.
- Sticker on top = CD death.
- Take care of your media. Had a friend who left a CD on the windowsill and forgot about it. Many months later, you could see right through it. Nice corrosion.
I find it weird that anyone can stick a 100 year lifespan on a product that hasn't been around that long. I know that they have processes that supposedly accelerate the process and give you a rough estimate, but I am skeptical. Maybe they really are that durable, and people are just careless/cheapskates. You know what they say about malice and idiocy.
Auto-reply to ACs: "Truly, you have a dizzying intellect."
Factor that in with the project the BBC did in the mid-1980s (A digital Domesday book, designed to be a snapshot of life at that particular moment of time) that was unreadable withing 20 years because of the fast pace of technology and no way will CDs last 100 years.
HAH! I just wasted a second of your life making you read this, but I wasted a minute of mine thinking it up. DAMN.
Blank CDs in bulk are cheap. For archival stuff I make a new copy every 5 years. I have a bunch of scanned photos I don't want to lose, so I re-copied them all onto new CDs.
You aren't supposed to write on the CDs either but I've not had any trouble with that, probably because I'm not trying to keep them very long.
I have CDs that were made about 7 years ago that are in relatively good shape and run just fine. They have the usually tiny scratches and dings, but... I don't get where people state that CDs will magically stop working after so many years.
We have secretly replaced these Slashdot mods' sense of humor with a rusty nail. Let's see if they notice!!
What's the deal? This same article with a slightly different look shows up every 6 months, it seems.
Besides the fact that CDs DON'T have a 100 year shelf life, we've also discussed the CD eating fungus several times here, which for people in hot and humid environments (particularly, it seems, Mexico, Central, and South America) can reduce a CDs lifespan to months or a couple of years.
And then you have the fact that rewriteables have an even shorter lifespan.
One thing that's rarely mentioned is the fact that most CDs are defectively manufactured. I say this because the metalic layer between the plastic is supposed to be sealed. But the fact that the aforementioned CD eating fungus enters through the two layers of plastic says to me that CDs are generally defective in that they fail to properly seal this layer.
I personally lost about 25% of my CD collection to this fungus over a 2 year period in Mexico, so I speak with some experience. These CDs were not abused. Most were in plastic cases, some were in sleeved carriers.
Some of my first cds purchased in 86 (Are You Experienced and Electric Ladyland) are clearly losing sound quality.
love is just extroverted narcissism
I don't get this obsession with hoping to keep media for 100 years. Technically punch cards are forever. Do you still use them ? No, because their storage capacity is ridiculous by today's standard. In five years you will store your data probably on your solid-state 200 g key-chain.... move with the times..
All this about CD's not lasting very long is just FUD by the RIAA. In the next few years or so they will want to bring out a new type of media so that everybody has to restock their cd collection with the new media format.
...
Bottom line, buy cheap media then you will suffer the consequences. Buy decent media; buy a reputable brand and you can expect reasonable lifespan.
Hey, and wasnt this a dupe? albeit one with a twist ?
nick
Electronic Music Made Using Linux http://soundcloud.com/polyp
Anybody want to fund me? :) Is somebody already doing this? I might be interested, I've got files I've been kicking around for almost a decade that I'd hate to loose.
The meek shall inherit the earth, in 3 by 6 plots. - Lazerus Long
I know that was meant as a joke, but last time I checked, most of my 10-15 year old Amiga floppies still worked fine. A few months ago I also started checking all my old PC floppies to see what the hell I had on them. These were mostly just crappy, knockabout disks, but only about 1 in 15 had any kind of read errors (and I was making complete rawrite-style images of the disks to store on a backup CD). All the official floppy disks for older PC software still worked perfectly.
Guess what I'm saying is that provided you take care of them and keep them stored in their boxes, out of the sun, away from your home-brew MRI machines and soforth, floppy disks aren't that bad. I've seen worse among CD-Rs...
The article says Not all optical media is vulnerable. The rewritable variants (RW) use metallic materials that change the phase of the light, rather than light-sensitive dyes. Commercial magneto-optical and ultra-density optical systems are different too. Do they mean to say that CD RW's are resistant to aging compared to CD-Rs ??
I always thought that CD-R s are more reliable than the RW's and genrally back up my data to CDRs ( and of course CDRW are more expensive)
On a related note, I recently recovered all of the contents off of the lone C-64 5.25 in floppy that I saved from my junior high/high school days of the late 80's. The disk had been sitting in between the pages of a programming book for around 15 years.
... no wonder I'm an emacs freak!
I found a very nice person who had a Commodore 1571 disk drive hooked up to his PC and was able to get the files off. I was really impressed that after sitting around for 15 years, the data was all completely readable.
I was also amazed to learn that when I was in junior high I was using a program called "SpeedScript" which I had typed in from a Compute magazine, and it had, to some degree, EMACS KEY BINDINGS!!! Holy crap, I had no idea that the emacs seed had been planted in my brain so early on
When I buy a cd in the store, I expect professional, archive quality CDs. If I've got to burn off the music myself (and can only do that a limited # of times) I've got to use my cheap 'ol cds. I guess most music services would track you're licences and let you download them again (provided you're computer hasn't changed, God I hate DRM). Still, at 99 cents/song with only shaky garuantees I can access the song perpetually, it seems like a raw deal.
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
I love vinyl... and believe me, the only thing that will make vinyl come back is when those vinyl turntables with a laser reader come down in price
http://en.wikipedia.org/wiki/Laser_turntable
8,000$ is just not within my disposable budget.
Many people seem to suggest reburning data every few years. But each time you do this, are you not risking corrupting a small number of files? I know OSs and hardware have error correction, but when you're dealing with gigabytes of data isn't there a risk that eventually an error will go through uncaught?
My grandfather made some wire recordings back in the 40s, we still have a machine that plays them back. It's amazing the longevity of those things, no wonder they use them on flight recorders.
I wonder if anything will be left of the last 50 years or so for the ape archeologists to unearth...
It's actually a great archiving idea. Something along the lines of Freenet. Distributed, anonymous, redundant storage.
Using P2P software, you supply:
a) n bytes of data you want archived
b) 10Xn bytes of free space to archive other people's stuff
So you've got 1GB you want preserved forever? Supply 10GB to the network, and the software takes care of the rest. If a user drops out of the network, his "stuff" is purged after 30 days of inactivity, freeing up space for new participants.
The cure for cancer is coming: Reovirus
The ONLY brand of CD-ROMs that I've found to last a long time are the Kodak ULTIMA series. Sadly, Kodak has stopped producing these CD-ROMs. I have several that I burned back in 1994-5 and they all still read with no errors.
I wish Kodak would bring these CD-ROMs back into production; I'd even be willing to pay a premium for them. When it comes to archiving data or something precious (like your late-grandfather's voice or late-mother's audio diary), cost really isn't an object. What's important is protection and preservation of history (in a sense).
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
pronoblem
When I have something to send somewhere, and I have to be sure it works, I just make 3 copies of it in directories 'copy1' 'copy2' and 'copy3' on the CD. A while ago I would lose copies of Windows98 on CDs because of the messy environment and (temp + humidity), so I'd burn multiple copies on the same disk. Almost 9 years on, I found a disk containing Quake2, the first and third directory were bad, and the second directory had just one file that was bad. I found a good copy of that file in the third directory. The CD didnt look like one byte could be read from it.
Another time I couldnt read CivNET from the CD and really wanted to play it 5 years after I got it. It was all scratched up. I rubbed glycerine on it (which has a refractive index close to plastic and sticks to it) to fill in the scratches enough for the data to be read. After several hours and many attempts of glycerine, try, wash, glycerine, I recovered the important files off the disc (movies couldnt be recovered.). Needless to say the drive died soon after.
If a company steps forward to sandwich two clear plastics with the silver between them, and glues the sides real well for archival purposes, I think they'll make money.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
I wouldn't be so keen on having particles of electrically conducting graphite being spun off the disc inside the drive... But you're right that it probably won't damage the disc.
If you're very paranoid, you might consider not labelling the CD at all
Or write in the data-less area around the center of the disc.
Avantslash: low-bandwidth mobile slashdot.
CD-RW disks will last longer than CD-R because of the way it stores it's bits.
CD-R uses a dye that changes color under influence of light. CD-RW uses a phase change material that changes it's properties because of heat. The phase change material won't change color but changes the way light passes through it. Differences in the duration of the laser hitting it will change a bit from one phase to another.
CD-RW disc information is much safer because of these differences. The only problem with CD-RW is that you can accidentally overwrite files you wanted to keep.
- -- Truth addict for life.
The number of things that can go wrong with old magnetic media is so long I won't even go there. If nothign else, the magnetic tape will get old and brittle. It also stretches slightly when you play it, which could leave granddad sounding like James Earl Jones in a few years. Certain types of mildew love it. AAAAAA! Make a copy! Make a copy!
Add to that the cost of replacing r2r tech, and you've got a scary situation. I agree with the parent. CD may not be the answer, but digital sure as hell is. I'd be super paranoid having anything I cared about stuck on old tape.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
I don't claim to know much about this at all, but I know as a complete fact that the slower I burn Audio CDs on my 24x the less they'll skip when they're in my car. This has been true for me at least one hundred times over, and I drive the same route pretty much every day (same bumps).. How does this experience fit in to the above?
I have, since 1984, written all my school papers, letters to friends, etc., on a computer, starting with WordStar 3.3. I thought I had a foolproof method of preserving them...every time I got a new machine, I just copied all the documents over to the new machine (first using laplink cables, later ethernet). Now, 20 years(!) later, I have my documents on my shiny new dual G5. And guess what! I can read maybe a 4th of them as no program understands the WS format, later WP4, WP5, etc. etc. Sure I have all the documents, but the all I can show off to my grandkids is a random collection of bytes that was "Why are oceans necessary?" from 1984.
But it doesn't end there...people talk about magnetic tape as being a viable medium; I have plenty of tapes that don't play right because they were recorded with a different speed recorder than what is available today. My little piano recital sounds like a Keystone Kops tune on acid.
And how about all those betamax tapes I've got of me playing tackle football when I was 11 years old? Still got 'em. Wish I still had a Betamax to play 'em on.
And then, I have a bajillion slides, taken by me and my family, on Kodachrome25. Stuff lasts forever. They've faded a bit, but I can still view them if I hold them up to the light. Wish I could show 'em to my grandkids but I don't have a slide projector. I suppose I could scan them into the computer......
But I think the problem is that CD media doesn't have what most people consider "acceptable redundancy"
When a CD ages, and the surface scratches, and the ink degrades, the data doesn't fade to yellow and get wrinkled like a newspaper, or it doesn't sound like its being pumped over a telephone like a record would, it is just gone. At least with analog data (especially newspaper) there isn't this working/not working parity...we can see the degradation and recopy the data before its too late.
Of course we try to get around this by adding error detection/correction schemes, but I think the original post is about how (apparently) these aren't adequate.
I gave an example above where I said I put all the important things on a hard drive, pull it, and put it on the shelf. This works for me, because I'm only interested in short archival period: like 5 years.
In the poster's example of wanting to repeat another 30-year archival... I'd have to imagine that ATA33 hard drive might not hook up to my grandkid's quantum computer 30 years from now.
So I would look into pulling a plug on a whole working computer. In other words, I would go to mini-itx.com and but a $99 motherboard, build a cheap box, slip in an above-average hard drive, get the cheapest possible LCD or monitor, install everything that is needed to make it work, load up the hard drive, and then pull the plug and store the computer. I would hope that the only thing needed to work in 30 years is a compatible power plug.
Why are there only 19 people folding@home for slashdot?
Second, the biggest mistake most people make in CD archival is to write on the CDs with magic marker -- DO NOT DO THIS. The ink will, given several years, leach through the extremely thin plastic on the labelled side of the CD and pollute the optical layer, resulting in a ruined CD.
Got some studies supporting that? I did my own little study after highly doubting this rumor. Here's how I think the rumor got started:
1. Buy cheapest Taiwanese media
2. Write on it with a Sharpie
3. Down the road, blame the Sharpie for media failure
My (unscientific, but the only data point I'm aware of) test:
In 1996, I wrote all over a Japanese Taiyo-Yuden made, unbranded Sony CD-R. In 2003, I tested the data, which was fine. I then cleaned the Sharpie ink off the disc with carburator cleaner (harsh treatment, for sure). It wiped off in seconds with no trace whatsoever, so in 7 years the ink did not migrate into the disc at all. After this, the data was still good.
Conclusion: Buy good media and quit worrying about writing on the discs. They'll take it fine, and if they die, it wasn't the pen that killed them.
It would be interesting to see if the difference between readin and writing speeds causes the problem. Since if you write at the same speed as you read both processes will see the same wobles in the disk. These wobles are caused since CD's are never quite round, and uniform desity.
This would mean that for a normal CD player you want to write at 1x, and for a Car cd player, or a portable CD player you would want to write at what ever speed they sample (more than 1x since they have skip protection). If you check the site they meantion that you should write at more than 1x but less than 12x.
So the question is at what speed they wrote and read the CD-R's, not just the writing speed. I checked the site but I didn't find any data on that.
So much for ELUA terms to the effect of "You may make ONE archival copy."
If the medium fails in a couple years you need several. First, you need to make a string of them to "refresh" the data before the old disk fails. Second (since the failure is statistical) you need several copies to obtain the redundancy necessary to recover from any errors that occurred during storage. And you should also keep a previous generation, in case you need to recover from errors introduced during the copying process.
So you need a LOT more than "a SINGLE backup copy" to have an adequate backup. IMHO (IANAL) this makes such ELUA terms ludicrous, and a violation of your first-sale rights - another strike against the reasonableness of the portion of the DMCA that says such contracts are enforcible.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
We burn about 200K CD-R's here per month. We have found, unequivocally, that you can burn data CD-R's at 40x, but the best we can do for audio is 12x. We don't really know why, but we think it has more to do with the error correction capabilities that the data format has. That's the theory, anyway. Of course, we use only the best drives and media.
(phthalo)Cyanine cyanide. Cyanide makes you look cyanine (blue/greenish), though.
When did people officially stop caring about listening closely enough to distinguish even barely homophonic words?
We all know that clay, stone, and ceramic records can last for thousands of years in terrible conditions, but those records are kilo-bit order projects, and an entirely different animal than sound.
One thing this guy may want to consider is a Rosetta type of storage system. If you convert the reel-to-reel recording to a digital format, then transcode to a uuencode style format, the result could be recorded in an extremely stable human and machine readable format.
If the guy really wanted stability and long term interpretability, he could encode a 1Khz sine wave using the same method and use that as descriptive meta-data. That way future generations could have nice, simple test file to run their automated decoders on. Even if all knowledge about how the file was encoded is lost, the repetitie pattern would probably be noticed. If the archivists in 2152, common era, have any idea that the disk is a sound recording, they'll surely figure the rest out.
I work with a amateur historian that's quite looney, over all, but she is always making good points about meta-data. Recording information about the sound, how it was made, who made it, and anything you can think of might make the difference between a sad lost opportunity and a major discovery. Historian types really love it when they find an old picture with names and dates written on the back. Often they can use their other archives to cross reference and to infer information that would be impossible without the meta-data. For example, they could use a known good picture of a certain building, and a picture of a person with a part of said building to place that person in a certain town at a certain time. That's a small example, but anyone can see how important a small point can be when trying to figure out a puzzle with 90% of the pieces destroyed.
Also, the guy may want to think about getting the originals into proper storage. That may mean giving them to an institution, but it beats having them destroyed because your cat peed on them.
People are spending big bucks to recover wax cylinder recordings of opera singers. Surely they'll do it for actual historical records put down by eye witnesses!
This guys sounds interested enough to re-record every 5 years to the latest and greatest storage technology, but what about his heirs? If fate curses him with Alzheimer's disease, will his kiddies care of have enough energy to do the job? Probably not and the chain could be broken. That's the real threat, I think.
Why do I have this? I don't smoke.
Clay Tablets, they seem to have the best proven track record for data as a whole. Of course, if you have the money, you can always use a norsam disk, they may last even longer than clay- but I doubt they're cheaper. Of course, for large amounts of data, storage is a problem.
Seriously, there should be a digital->clay device, like a printer or something, for super-archival 4000 year proven quality at a bargain. I have thought about making one for a while- a sort of dot-matrix for clay. I think it would be fun!
I think it depends on what information one considers important. The more different information you have, the less durable each corpuscle of it is. The more identical, permanent, memorable information you have, the more durable it will be. Of course, I think it would be difficult to put audio on a clay tablets, but not lyrics. We have the songs to Inanna by Enheduanna even today- that's some star power.
For years now, I've been seeking out water-based markers to write on CD-Rs, and they're increasingly hard to find. The first ones I bought - Dixon Ticonderoga Redi-Sharp Plus markers - were discontinued, and I'm running out of them. Anybody know of any other specific brands/makes of water based markers?
Maybe CD players could flash something like "hey I can't read 25% of the bits that are coming in, maybe you should make a copy of this CD" instead of working perfectly.
I was one of the original developers for Magneto Optic for MaxOptics and Pinnacle Micro Systems approx 20 years ago. I still have media recorded back then on truly rewritable optical media that is 100% flawless to this day. And all this is on Plastic Media. I never did understand why magneto optic didn't catch on more. The Glass Media units I'm sure would go to 100+ years and were tested in Europe for the telephone and data companys 20 years ago, and the last I heard they still hadn't seen a single cartridge with glass media go bad.
For the record, here's what the Council on Library and Information Resources says (emphasis mine):
Is this just theory or does it really happen? Does anybody have a CD or DVD that became warped because of storing it horizontally? Almost all disc storage towers and cases hold them horizontally.Reminds me of that poem by Percy Bysshe Shelley:
I met a traveller from an antique land,
Who said -- "Two vast and trunkless legs of stone
Stand in the desert... Near them, on the sand,
Half sunk a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things
The hand that mocked them, and the heart that fed;
And on the pedestal, these words appear:
My name is Ozymandias, King of Kings,
Look on my Works, ye Mighty and despair!
Nothing beside remains. Round the decay
Of that colossal Wreck, boundless and bare
The lone and level sands stretch far away."
That's probably because CD writers use CAV (constant angular velocity) for writing speeds above 12x. CDs were originally developed to use CLV (constant linear velocity), meaning that the rotation speed slows down as the head goes toward the outer edge of the disc--if you have an older CD player that lets you see the spindle or CD while it's spinning you can verify this (it's easiest to see when the head is seeking from one edge to the other). I'm not an expert in CD technology, but I've had similar results using discs burned at 12x vs. 24x on a 24x writer--the 12x discs work better in older players and CD-ROM drives--and I suspect it's because of differences in the way the disc is written between CAV and CLV.
If I'm talking out of my ass, I'm sure someone will correct me . . .