The Myth Of The 100-Year CD-Rom 671
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."
Nonsense! (Score:5, Interesting)
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.
CD Rot (Score:5, Interesting)
- 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.
Doooom(esday)! (Score:5, Interesting)
date, reburn, rinse, repeat (Score:5, Interesting)
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.
Re:CD Rot (Score:2, Interesting)
In fact, thinking through my CD-R library, I can't think of any labeled CD-Rs that have ever gone bad on me. I can't say the same for labelless/stickerless?
Unless you scratch them, shelf life is long. (Score:2, Interesting)
Another 6 months, another CD longevity article (Score:5, Interesting)
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.
my first audio cds are dying (Score:3, Interesting)
Re:Doooom(esday)! (Score:5, Interesting)
Why 100 years ? (Score:5, Interesting)
FUD (Score:4, Interesting)
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
Free Biz Idea (Score:2, Interesting)
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.
Re:Solution! (Score:1, Interesting)
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...
CD RW are better ??? (Score:3, Interesting)
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)
Commodore 64 Disks (Score:3, Interesting)
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
Brings up a good point about buying mp3s (Score:3, Interesting)
Re:Long term audio storage (Score:3, Interesting)
http://en.wikipedia.org/wiki/Laser_turntable
8,000$ is just not within my disposable budget.
Re:Nonsense! (Score:5, Interesting)
Who's really going to remember this schedule?
This is my beef with digital photography: I found a negative for a photo that was taken sometime between 1891 & 1934 - prints were beautiful. This negative was not stored properly at all. No special effort to preserve.
With digital photography & CD-R disks I'm not so sure that we're not just creating a set of transient memories which will disappear into the ephemera in 10 years time.
Re:Doooom(esday)! (Score:3, Interesting)
Risk of data loss for nth generation copies? (Score:4, Interesting)
I've still got wire recordings... (Score:1, Interesting)
I wonder if anything will be left of the last 50 years or so for the ape archeologists to unearth...
Re:Eternal archiving. (Score:3, Interesting)
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.
10-year-old CD-ROMs (Score:3, Interesting)
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).
best bet... (Score:4, Interesting)
Re:First of all... (Score:3, Interesting)
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.
Re:CD-Rs can last longer (Score:5, Interesting)
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.
Re:CD-RW slow rot (Score:3, Interesting)
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.
Reel to Reel WILL FAIL (Score:5, Interesting)
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.
Re:Writing speed (Score:4, Interesting)
No easy solution at all (Score:2, Interesting)
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......
Re:First of all... (Score:4, Interesting)
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.
Re:Old formats require old machines (Score:3, Interesting)
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.
Re:Nonsense! (Score:2, Interesting)
The Sharpie rumor again (Score:4, Interesting)
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.
Re:Nonsense! (Score:4, Interesting)
Then obviously you couldn't have copied all the data to the "current" medium in the first place.
Re:Writing speed (Score:3, Interesting)
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 - another ding for DMCA. (Score:2, Interesting)
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.
Re:Writing speed - audio vs. data (Score:5, Interesting)
Re:Nonsense! (Score:5, Interesting)
Uninformed (Score:1, Interesting)
When did people officially stop caring about listening closely enough to distinguish even barely homophonic words?
Re:Nonsense! (Score:2, Interesting)
I have pointed out how many of them currently have a 5.25 floppy drive around (none). Same deal in 20 years with CDs. You may have stuff backed up on them but are you going to have the equipment to read the data, that is if the discs aren't junk? Somebody will have it, but you'll pay for them converting it or doing data recovery.
I'm not saying I'm not digital, I just make sure everything is backed up across my home network and on multipe CDRs and/or DVDs which are stored at my mom's and in-laws places. "Here's a CD of your you grandchild's pictures" = easy off site backup. What granddad is going to turn down pics of their little grandbaby?
Alas, I'm the nerdy computer geek that worries about things too much. Well at least I'll have the pictures of my baby daughter for her to pass along long after I'm gone. I doubt I'll ever here, "You were right all along," from them, even if I am proven right. Let's hope I don't have to hear it.
Historical Considerations (Score:3, Interesting)
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 [norsam.com] type of storage system. If you convert the reel-to-reel recording to a digital format, then transcode to a uuencode [datafocus.com] 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! [imls.gov]
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.
I always use (Score:2, Interesting)
Clay Tablets [wikipedia.org], 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 [rosettaproject.org], 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 [about.com] even today- that's some star power.
Re:NIST Study (Score:2, Interesting)
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?
Re:First of all... (Score:1, Interesting)
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.
Re:CD Rot (Score:3, Interesting)
I've successfully used BlindRead/BlindWrite (www.blindread.com) to perform raw reads of otherwise unreadable discs - and I'm talking CD-Rs that can't be ripped in a CD-ROM, played in a stereo CD player or *anything*. BlindRead instructs the reading device to ignore the error-correction encoding, which may only confuse matters when the disc is mechanically damaged/degraded. Once read in (as an "image") and burned to a second (usually RW, to conserve resources) disc, I could frequently recover the content in sufficiently flawless (for audio, at least) condition for material for which I had no other source. A few discs were just lost completely. (Taught me to NEVER erase or record over the master DAT.)
A note on manufacturers: It's getting more difficult all the time to find blanks sourced from reputable manufacturers. a) most "brand name" blanks [Fuji, H-P, Imation, etc.] are actuallly manufactured by other companies [Ritek, CMC Magnetics, Taiyo Yuden, etc.]; b) the "name brand" companies change their sources to minimize cost at whim and with no notice to the consumer; c) there's usually little outward indication of the actual manufacturer to tell you, when looking at spindles of blanks on a store shelf, who made them, in order to decide which to buy.
Up till sometime last year, Fuji and H-P sold re-branded Taiyo Yuden blanks. T-Y blanks have tested (in BLER tests similar to the Library of Congress studies cited in the story) as competitive with the best quality brands, FAR better than Ritek-manufactured discs and those of other mfrs. (Sorry, I don't have a ready reference for that data at hand,...) But recently, both Fuji and H-P have gone to another source - the only outward evidence of which on their packaging is a "Made in Taiwan" where there used to be a "Made in Japan" legend, and the spindles look a little different; SOMETIMES the label side of the disc is different, but not always.
In order to determine the actual manufacturer of a blank, you need to use (on the Windows side) a utility program such as CDR-ID or Feurio (www.feurio.de), the latter of which displays the manufacturer in a pre-burn dialog box.
As a side note, other brands whose blanks tested at the top of the curve, were those manufactured "in-house" - Verbatim, Mitsui and Kodak all make/made their own blanks, and they tended to have better quality control. Of course, they also tended to be more expensive, and Kodak has since stopped making their own blanks.
Another thing I've noticed recently about "off-brand" CD-RW blanks (and I'd guess it's the same for CD-Rs, but I've never bought any CD-Rs branded by these low-budget outfits), is that it appears that ValuDisc (ValueDisc? Valu-Disc?) and possibly KHypermedia blanks are REJECTS from other re-branders. I snagged a spindle of Valu-Disc CD-RWs on a free-after-rebate deal at OfficeMax a couple weeks ago. On close inspection, the top coating appears to be a thick blue dye/paint layer, made from many, many skewed layers of logo-print, all in the same color, and augmented with a few solid layers, apparently in order to disguise a logo that had originally been applied to the surface of the disc. Anybody know anything about this? Are they selling blanks that were labelled for one reseller, rejected "en batch" by that seller's QC, and then painted over to cover the original branding? I've not written data to any of them yet, and so don't know how they perform,...
Magneto Optic (Score:4, Interesting)
Re:Store CDs upright? (Score:3, Interesting)
For the record, here's what the Council on Library and Information Resources says [clir.org] (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.Ozymandias (Score:3, Interesting)
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."
Re:Writing speed - audio vs. data (Score:3, Interesting)
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 . . .