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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."
Or just burn to multiple cd's, that way the chance they all go bad is low.
The 100 year CD-ROM becomes a 27 million year CD-ROM, and they plan to have their copyrights extended that far.
Store them on a series of floppy diskettes. They have proven to be VERY reliable. ;)
Ever decreasing circles
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.
but it seems that old analog tech from the '70 is more reliable than digital.
While the media itself might be seen as more reliable in this case, the means of accessing that media is a different story. No saying what will be around in another 20 years, though some sort of disc in the shape of a cdrom is probably a likely.
Rename the MP3s of your grandfather's voice to coors_twins_baby_oil.mpg and put it on Kazaa.
Repeat every year with the current cover girls of Maxim, Stuff, or whatever men's mag suits your fancy.
Guarantee you'll never be at a loss for a copy of dear old granddad.
3D Printing Tips and Tricks at Zheng3.com
I know lots of people that have "worn out" cd's. The first time I heard that, I thought they were kidding, but no... even if you take super great care of say, an audio cd, it will eventually wear out. It's especially bad if you keep it in the original plastic jewel case, and take it out each time -- my friend's rare Pearl Jam CD's are nearly scratched beyond playability, but he was able to extract the digital information before it got lost. What makes CD's better than tapes is that the 0's and 1's will always "be the same" logically, unfortunately the physical media wears out quickly with use. I prefer to think of CD's as a temporary storage mechanism for a permanent idea, like a sketch on newsprint. Once the newsprint disintegrates, you'd better hope you made something good with the idea... it doesn't mean the idea is gone, but the medium isn't like stone.
stuff |
Is this just new media they are talking about or is older media included? I remember a long time ago it seemed as if the quality of the media was a lot better than it is now(makes sense). I have cds over 5 years old that work better than ones i burn today. Is this a problem with the quality of the media, the write speed, or just all CDs?
Right now I keep everything backed up to a second hard-drive and on disk... it doesn't have to last forever, but if CDs randomly go bad with no way to tell, and after three hard drive crashes this year alone I have little faith in them lasting... are there any other good long-term ways to store large amounts of data, other than what I'm already doing? (In my case, huge scans of image files.)
Since reading a previous story I already make sure I store all my CDs horizontally, and use the good, more expensive ones for anything I'm archiving for the long term.
My Webcomic: Asylum on 5th Street
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!!
The danger in "old" storage formats is lack of machines to read them. Those tapes may be in good shape, and so might the data on an 8" floppy I have, but the 8" floppy is effectively lost to me because I don't have easy access to a drive that can read it anymore! The paper tape programs I "printed" out from a VAX PDP-11 are probably good (if I hadn't lost them years ago) but I can't get to a tape reader, etc.
You almost have to make dozens of copies of data on a modern cheap format, and keep moving it forward.
How do you know there is no loss with analog?
Analog quality loss is acceptable, because it results in static. Digital loss isn't acceptable, because (at least practically) it is a binary property...the CD works or it doesn't. Scratch the hell out of a record, and at least you still have something.
We could build acceptable redundancy into digital backups, its just that most people think of it as wasteful. You know what though?... I have everything worthy of backup "backed up" in at least 3 places, one of which is always CD stored somewhere out of reach. Digital is better. Once you convert to digital, you can have zero quality loss with near 100% efficiency, you just have to want it that bad.
It's not exactly a fair comparison between CD-R and analog tape for audio. The audio tape isn't "more reliable." It just degrades differently.
As the tape ages, the quality of the audio signal degrades dramatically, but because it is an analogue signal, it can still be deciphered by or ears.
With digital medium, the audio never gets worse. As the media degrades, it just reaches a point where it isn't able to be deciphered as audio data.
If you want to compare the mediums (magnetic tape vs. CR-R), data is probably a better place to do so. You can easily measure the amount of readable/unreadable data in bytes and make a fair, quantifiable comparison.
In the wrong conditions, such as sunlight, humidity and upper surface damage, your CD-R will slowly turn into a coaster. "CD-Rs should never be left lying in sunlight as there's an element of light sensitivity, certainly in the poor quality media," says Stevenson. "I wouldn't rely on CD-Rs for long-term storage unless you're prepared to deal with them as recommended."
Surely storing cd's correctly is the key, if the dye on a cdr fades after being kept in a jewel case at a room temperature fr 2 years then that is obviously very bad (and there could be some lawsuits in the future).
Set up a a couple of raid storage devices in two or three data centers, preferably one on another continent than the one you live. Set up some sort of auto-syncing mechanism and be sure to change out your disks twice a year for extra safety. Actually, it would be best to buy all new equipment yearly. Also, contract at least two remote backup services to backup your data nightly. Do this, and you can be sure your data will be safe forever (barring nuclear war or a massive asteroid striking earth.)
Mine dont last 10 seconds... in the microwave.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
Keep original copies on the Harddrive, Cassette, ect and then make copies as needed.
Tape isn't going to last forever. At least when it's digital you can easily transfer to new media without loss of quality.
If it's really important you just need to make sure you keep ahead of obsolecence. Transfer the stuff to the new standard before the old standard completely goes away. There's always a transition period.
Ben
Work Safe Porn
I have found most of my cdr's that are that age or older are starting to fail.
Rather dissapointing the first time it happened.
seems to be from several big brand names, so it must be a limitation of the Dye, not just a bad batch.
But then again, it was designed to be written too ( i.e. physcially changed ) so how can one expect it to last forever?
---- Booth was a patriot ----
Burn to CD-R, keep in on your hard drive as a WAV, and keep the tapes too. That might still not be enough.
If you honestly want to keep your data for a long period of time, you may need to take extreme measures.
There are no trails. There are no trees out here.
Don't worry, with the recent success of resoring old recordings with QM tech, I'm sure that by 2200 there will be a way to restore data off a bunk cd-r;)
The first link is to rense.com, a website that promulgates the theory that the US government is experimenting on us with "chem trails" emitted by otherwise innocuous-looking aircraft flying overhead. The webmaster at that site obviously has a very low threshold for rubbish, and no critical thinking ability!
I bootleg Fizzy Lifting Drinks.
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 have yet to see any of my old copied CD-Rs fail (or anyone else's, for that matter). I don't expect them to fail, either.
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
The BBC Library still uses vinyl records for long term audio storage. For some items they cut a lacquer master, plate the metal stampers on the lacquer and leave the metal stampers attached to the lacquer.
They believe that this will preserve the audio for about 300 years and they say that vinyl is the only storage medium with a real and predictable life span.
Audio processing technology will get better. Don't ruin your grandkids' heirloom recordings by using today's technology to permanently alter them.
Make working copies and filter those as much as you want, but keep those masters pristine! Maybe somewhere in the background you can hear your grandma yelling at dear ol' grandpa to put that thing away and paint the house, and a clumsy run with an agressive low-pass filter will throw that data away forever. You have something really valuable; please take care of it for the future.
Dewey, what part of this looks like authorities should be involved?
Regardless of the fragility of the CD, digitized data can be duplicated as frequently and as cheaply as you wish. Redundancy is the surest form of protection.... and storage space is cheap. For an interesting backup scheme, see http://www.csua.berkeley.edu/~emin/source_code/dib s/
...is not that the CDs will decay and become unusable. The real problem will be that the file formats of today will be replaced in 10 years, and will be a legacy file format only readable with a compatibility layer in 20 years. In 50 years, that CD will be unreadable. Of course, storing it in ISO 9660 format would offer some protection. If nothing can read the CD 50 years from now, you could at least fall back to the standard spec write your own code to read it.
Oddly enough, I note that UDF is getting pushed as a replacement to 9660. So maybe even 9660 will be outdated faster than I expect.
Will CD drives exist then? I certainly can't get an old cassette tape drive these days, and that's only been 20 years. Hmm. I think in 100 years, the decay of your CD will be only 1 of many problems.
My Greasemonkey scripts for Digg &
The testing that is being done on these CDs is extreme. If you stored your cassette tapes in 60-80 degrees celsius and 85% humidity, the cassettes would also fail. Neither media is intended to be stored under these conditions. Just as these CDs are failing so do cassettes. There have been numerous times where my cassettes have become unusable because the have spent too much time in a hot car ~60C.
If your CDs are store in a cool dry place, out of direct sunlight they can certainly last 100 years your cassettes probably can too.
Now, you can enjoy your CDs for a long time...
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
News here in .dk had a report some days ago about public libraries beginning to have a crisis on their hands.
Many original CDs dated back to the early 80's are unreadable.
Technology has moved since the 80's, but still, this is a kinda prewarning that a lot of material will prolly disappear if better solutions are not around soon.
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
Personnaly I just discovered 6 audio cassettes with the voice of my late grandfather.....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
Go ahead and digitize everything. Then get yourself a couple of accounts at Gmail when it becomes available. Then email the audio to yourself. You will have it forever then.
Of course you will see a lot of google adwords for Geritol and Ben Gay, but nothing is perfect.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
Store your CDs in a cool, dry place which has a constant temperature, and if it's dark, all the better.
I am a believer of momentum and curves.
There's talk of UDF (DVD filesystem) being more resistant to errors than ISO9660; sadly nobody seems to have a source for this. While I doubt anything's going to help much if your CD/DVD-R's have things growing on them, does anyone know enough about these filesystems to comment?
a well-informed friend of mine told me back in the 80's to NEVER use CD's for archival purposes.
thankfully, I haven't. Most Cd's i burned more than 5 years ago are screwed.
What about this: disks made out of diamond, and then use lasers to store data on them.
Well, we know about CD-Rs degrading quickly, but what about DVD-Rs? Are they similar in degredation or different? How long can i expect my Bulkpaq DVD-Rs to last?
It's all well and good to have a CD to back up your precious files (Audio, Video, documents etc) to but this doesn't cut it as a real backup.
With disk space being so cheap now I keep a copy of all of my important data on my server, mapped drives to connect etc. I then have a login script that runs on a workstation and backs that data locally to the workstation (now I have two copies) - Windows users can use Robocopy and *nix users have rsync, both of these tools are exceptional and only copy the newer/changed files so the backup of 50+ gigs of data seldom takes more than 15 minutes.
I then back that up to one of two external hard disks, one of which is always in a safety deposit box.
CDs never were and never should have been a good backup solution. The technology will change. A good backup solution is one that changes with the technology. I know that these external drives will one day be obsolete but to there is no degradation of data like a CD that has flakes falling off of it after 2 months.
It's also far more cost effective and as I upgrade my computers over time I know my files will be updated too and when the tech moves beyond external hard drives I'll change the solution then. Backing up to CD once like that is asking for trouble if you never test the media, like I do on a daily basis, I still have old school assignments from 10+ years ago, pictures and business data that I know I will never lose.
John the Kiwi
He might have been referring to those DIY stickers that you print and add yourself. Those are very hard to align properly, and with some wear and tear may easily become unusable due to lack of balance.
Preprinted labels I don't see making a difference though, at least not a negative one. Aren't CD-Rs pressed in pretty much the same way as a real pressed CD, except for a writeable layer with less protective coating? I thought the top label would be pretty much identical...
Kjella
Live today, because you never know what tomorrow brings
Real men don't make backups. Real men post to the internet and let the world mirror ir. Or something like that.
That which does not kill her only prolongs my agony.
I'm sure what I'll say has already been said, but I can certainly attest to the shorter-than-advertised longevity of CDR media. I recently had to pull some long lost files off of CD's I burned back in the college days, probably 5 years ago or so. These consisted of several types of media, both cheap and expensive, green and blue dye, sticker and no sticker. Basically the dye color has little effect, and stickers really do call for the early death of the media. But most of all, I think it was the early CD burning software or the actual CD-Rec drive that I used. Some earlier CD's, that I know I burned at work (using the latest software at the time) were near flawless. But a batch burned later, on a friend's computer using some lesser known software, was completely corrupt (TOC and CRC errors abound). I now make sure I get decent CDR's like TDK's (not the cheap CompUSA stuff), don't use stickers, always keep them in a multi-CD case, and run a bit-for-bit check on the archive after burning with Nero. I have yet to have a problem since I started this practice at least 2 years ago...although time will certainly tell.
Sometimes I doubt your commitment to Sparkle Motion.
are there any other good long-term ways to store large amounts of data, other than what I'm already doing? (In my case, huge scans of image files.) I agree. The needs of the really dedicated pron archivist are being overlooked here. How would normal people like it if their significant other became slowly degraded over 10 years and became covered in dints and imperfections?
Magnetic media like cassettes, VCR tapes, and floppies will all degrade with time, just like CDR's. It's probably hard to tell with your old tape but I seriously doubt it sounds as good as it did back then. It's just not that big a deal because our brians are excellent audio decoders. Every time I have to use a floppy I literally go through 5 to 10 floppies just to find one that works because they are all 6+ years old.
Unlike analog data, digital data does not degrade. The media might degrade but the actual data does not (it either works or it doesn't).
I just upgrade formats every couple years. For example, I had a bunch of digital pictures on floppy many years ago. When CD recorders got cheap enough I moved them to CDRW. Just recently, when DVD recorders got cheap enough I moved them to DVD+RW. Next will probably be to the new 8GB DVD-R's. Even though I have more data, I still use less media because the new formats always hold way more than the old versions. I never have to worry about quality degradation because they are exactly as they were when I originally made them.
The ratio of people to cake is too big
I now write myself a little note on my CDRs to indicate how much of the surface causes read errors. Nero's "CD Speed" tool is very useful for this, as it has a ScanDisc tool incorporated within it.
When too much of my CD's surface has read errors, I make a new copy of the CDR. So far I've only had to do this for 3 of my discs over the past 6 years or so.
Although it seems like burning at a slower speed means that your data lasts longer, for some newer CDs burning at 2x might actually cause your data to be less secure. Most CDs sold nowadays are optimized for faster burns, say at 48x. The "fast" media doesn't handle slow burn speeds quite as well as older media optimized for 2x would.
If their technology is so great, they can enhance my audio files no matter the condition. Ever see Star Trek!? They take blurry photos, and then extrapolote and you see clear photos!
speaking of this, is there a service that does this that people on
convert everything to mp3, and send them to your gmail account, they will be kept here forever in multiple redundant copies
"Science will win because it works." - Stephen Hawking
Similar stories from Slashdot past:
CD-R Lifespan - Is It The Label?
Say Goodbye To Your CD-Rs In Two Years?
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)
I've got dozens and dozens of CD's with holes all in them, like someone sprayed acid on them or something, it's not eaten through the plastic at all, just the foil is gone. It's really weird. I can't explain what it is for sure but best guess is that about two years ago my A/C went out and I went 9 months without climate control, 100% humidity and high heat. Very miserable (I won't mention the name of the HVAC contractor though) and now I am wondering if that's what killed all those CD's.. I thought it was toner that got on them when I broke open a toner cart but I find that hard to accept.
The rot thing, I dunno, that's weird too...
Odd as it seems, the new technology that gets introduced every 3 years is your best friend. 6 years ago, we had CD-R. 3 years ago, we had DVD-R. Now we're going to have Blu-ray (or DVD-HD soon). Everytime a new format comes out, density of the media also increases. You can use this opportunity to transfer all your data on the old media to the new one.
The benefit is that you get to reduce the number of media you need to keep (since you can cram more to a disc in the new media format), and you maintain "freshness" of the media as well, everytime you "transburn" your data.
I once had a signature.
As far as I know the first CD-player (the Philips CD-101) came to the market 1981 !
that's why I bought the Unreal Tournament 2004 Special Punchcard Edition.
a /U T04-PunchCard.gif
http://img53.photobucket.com/albums/v162/Cordat
As long as I keep them in a dark and dry place, it's going to last forever!
That does it. I'm converting all my mp3 collection to 8-track tapes. Does anyone know of a good 8-track tape recorder that mounts in a typical tower 5.25" drive bay to make this easy?
Don't blame Durga. I voted for Centauri.
"Real men don't use backups, they post their stuff on a public ftp server and let the rest of the world make copies." - Linus Torvalds
I think you are doing the right thing. Who has time to dick around backing up to CDs, tapes, etc? To me, any backup solution that spans multiple tapes, etc is severely broken.
I have a big honkin hard drive 120gig with all my stuff at home. I have a 2nd big honkin 120gig that has USB2. I take the USB2 drive to work once a month and leave it there. Bingo--off-site backup solution. (Yes, encrypted file system so co-workers can't browse my comprehensive porn collection.)
The stuff that changes more often (like photos) that I couldn't really bear to lose I rsync to my linux box over the net.
Everything fails, redundancy is the way to go. And it has to be easy.
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The National Institute of Standards and Technology also has an extensive guide, Care and Handling Guide for the Preservation of CDs and DVDs, including a one-page Do-and-Don't Quick Reference.
Tape is just as succeptible to environmental conditions as CD-Rs. The tape can rot, distort if overheated, get wrecked by magnetic interference, or get eaten by a malfunctioning tape player. The fact is, if you're serious about keeping any sort of data over a long period of time, you should be careful and make sure you back it up again periodically. Anything else is leaving the matter up to fate, no matter how durable you think the media is.
Imagine you just kept the reel to reel recording. At some point it will be hard to track down a reel to reel player and you will be screwed.
...that this story(in various versions) has a longer lifespan than most CDRs...
Good thing I saw this... I was just about to get that CD-RW bio-mod installed in my head.
I guess I'll just have a cassette deck installed instead.
I will shred my adversaries. Pull their eyes out just enough to turn them towards their mewing, mutilated faces. Illyria
Because if it's on Rence then you know it must be 100% accurate. I have never known that site to say thing contrary to reality.
This article inspired me to listen to my second oldest burned CD (the first burned CD was a generic no name brand that had punctures in the data surface). It was a 74 minute memorex CD. Anyways, this CD dates back to my first CD burner (1999). I dug it out from the bottom of a spindle of CDs that were to be eventually thrown out. So after dusting it off, I threw it in to my DVD player, and it's playing right now, Semisonic and Bloodhound Gang and such, still fine, as the day I burned it. So from my experience, I'd say this is horse shit, or you buy really crappy CDs.
-------
Support Indy Music. Buy
That's why I buy bannanas by the bunch. I mean, what are the chances that after a year they all become rotton?
Anyway, about my washtub...I just used it that morning to wash my
turkey, which in those days was known as a "walking bird". We'd
always have walking bird on Thanksgiving with all the trimmings:
cranberries, injun eyes, yams stuffed with gunpowder. Then we'd
all watch football, which in those days was called "baseball"...
I don't think your great-great-grandkids in 2050 will be very interested
cat grandpa.mp3 | uuencode > /dev/printer
symetrix. We are building a religion, a limited edition.
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
... in other words, CD-Rs are only good for 4 years.
--== Radioactive cats have 18 half lives ==--
Then its good enough for me. Now, where do I buy a reel-to-reel drive to back up all my data?
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/
"Nothin' lasts forever but the Earth and Sky."
All CD-R is dust in the wind....
Analog methods of storage (such as good old paper*) will pretty much always be able to outlast any method we have to digitally store information, at least for each "generation" of copies that are required.
The benefit of analog is that you can store the original content for a long time, perhaps even indefinately if properly cared for. Digital, so far, seems to suffer from a lack of "permanent" media onto which content can be written.
The big difference, however, is that with some effort it is not required to have long-life media for digital. Unlike analog content (which degrades with each generation of copy), digital content copies perfectly from one generation of media to the next. Sure, it'd be nice if you could just archive one physical copy and store it forever, but since we realistically cannot, it's pretty good that a perfect copy can be made before it degrades.
Think of it this way: for decent preservation of analog content, you must exercise excellent dilligence in physical care; for perfect preservation of digital content, you must exercise regular, but rare dilligence in copying to a new media.
Besides, even if a "permanent" media is created for digital content, that's no guarantee that years from now the content can even be read. What good is it for your great-grandchildren to pull out your CD-ROMs 100 years from now, and have them find that no-one has manufactured compatible devices for over 80 years, and no one has serviced one for over 50 years? That data is just as lost as it would have been if the CD had degraded.
* Yes, I also know that today's paper is unlikely to last very long (relatively speaking), either. The papers used centuries ago withstand the aging process much better than your standard photocopier paper will.
Look at the tomato! Isn't it sad? He can't dance! Poor tomato!
I still have some archival Kodak Gold Ultima CD-Rs for saving important data. Unfortunately, Kodak stopped making them and exited the CD-R business because of declining prices. Kodak did some fairly extensive testing to characterize the expected lifetime of their CD-Rs. I worry that CD-Rs will follow the path of floppy disks. When they are expensive, the disks are of high quality. When the price declines to a certain point, manufacturers offshore production, eliminate QA and cut as many corners as possible to stay price competitive, leading to media that is utter crap.
Mea navis aericumbens anguillis abundat
So, not only will the Commodore disk drive provide superior preservation for your music files, it can play the music as well
Don't blame Durga. I voted for Centauri.
So then you must have scientific evidence to back this up then, right?
What, like the parent poster he was replying to?
Thats why I store everything on zip drives.
Everything was so much more reliable. All electronics today die so fast fast. my parents still use an old 21" 1978 television and it still works. How many newer TV's can stand that test of time?
This news item does have me concerned about my data. What is the top recommended CD-R brand?
Don't blame Durga. I voted for Centauri.
This means that if you have a 2X recorder, writing at 2X is *much* better than 1X. If you have a 32X recorder, writing at 32X will produce measurably better discs than writing at 4X, 2X or 1X. This has been true since around 1998 or so. It is quite true that you could get better results with some early 4X recorders when writing at 1X than 4X. However, none of those devices are current any longer.
The "writing slower is better" story is a myth. Please don't spread it further. And yes, if you want more information about disc testing Media Sciences is a company that is dedicated to disc quality and testing. I do not work for them.
There is another aspect of the prevalence of digital media. Inspite of the fact that commonly available high-quality paper which has expected longevity of ~500 years, and is more "resilient" to error, it seems that more and more libraries are pushing for the digital media storage way. Common "green" arguments against paper include: (1) It destroys rainforests. As far as I Know, paper is made from soft wood and pulp. So this is just a muddled argument. (2) You save trees by using less paper and using digital media - I do not know. All you need to read a book is sunlight (or) a 10-watt reading lamp. Compare it with most computers which consume more energy and the argument seems less strong. Is there some study which regards the per copy energy usage of a paper edition vs. per hit of a digital edition? There is an interesting book called Double Fold about the attempts to replace paper copies in the library with microfilms. It seems that there is an equal subversion when it comes to the digital media debate.
Anecdotes I've seen also indicate that they're the highest quality CD-Rs available and of the three dyes used on CD-Rs, their pthalocyanine dye is claimed to have the longest life. Anybody use Mitsui's gold CD-Rs and have problems?
... if you know what you're doing. First of all, there are specialty CD-Rs intended for archival purposes. These will inherently last longer than normal CDs for numerous reasons, assuming the manufacturers are not full of crap. To find these CD-Rs, check a photography store, as photographers tend to have a need for both archival and mass storage thanks to digital cameras. You will likely find some there.
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. Adhesive stickers, I'm told, are not much better. There are special CD-labelling markers out there, I don't know if they work well as I haven't tried them, but I doubt they're worse than a magic marker. I have found that writing very lightly with a soft, dark graphite pencil works well. If you're very paranoid, you might consider not labelling the CD at all and just be meticulous in returing it to its (properly labelled) case when you're done.
Additionally, store the CDs properly. Somewhere reasonable. Not in direct sunlight. Safely stowed in their jewel cases.
Of course, even doing all this, no one can tell you that your CDs will still work in 100 years. It hasn't even been 100 years since we invented the damn things, how do we know how long they will last? Still, these are steps that should allow your CDs to last for at least as long as a magnetic tape, and with perfect accuracy, as opposed to the slow degradation of audio tapes.
What we really need is something similar to the S.M.A.R.T. technology in harddrives nowadays, to alert you that "Listen, I'm getting close to reaching the limit of my error-correction techniques here. This media probably isn't going to last a whole lot longer. You may want to do something about that." Currently, there's really no way to tell until it's too late.
Random and weird software I've written.
omg jin wicked on teh spoke!!!!!!!1111111~~~
http://www.osta.org/technology/cdqa13.htm
Digitize your grandfather's tapes. Transpose the digital binary pattern into a DNA sequence. Latch that on to your favorite creature's "junk" DNA and let it procreate. Use a cockroach and your grandfather's stories will likely survive a nuclear war._ ______ __
___________________________________________
I've though of converting my 15+ year old video tape collection. However it appears that it will require quite a bit of money to do the job properly (e.g. TBC), and there's one other issue. I don't think that conversion brings everything over. Isn't closed captioning and other VBI information lost? At least my audio tape collection appears to be fairing well, even though it's older than the video tapes.
There is a company that has come out with long-life silkscreened "Our Wedding" DVD-Rs just to make sure that your $3000 wedding video doesn't evaporate on your 5th anniversary.
that cat's piss has a major detrimental effect of the life of cds. hint to readers - dont store your cds (backup or otherwise) in a cat-peeing-friendly box or corner of the room.
but it seems that old analog tech from the '70 is more reliable than digital
It only "seems" that way because you happened to find some well-preserved (and likely good quality) tapes. Even TDK carefully suggests that cassette tapes "can last for more than 30 years" if the following conditions are met:
Temperature: 15 to 25 degree centigrade
Humidity: 20 to 40%RH
Cleanliness of atmosphere: dust levels should be low
No strong magnetic fields near the cassette
No acidic atmosphere
No direct sunlight
And this lifespan also assumes no mechanical problems with the tape itself.
Do yourself a favor and archive those tapes on something (anything).
Really, what do you expect when most people pick up spindles that all some from the crappy Ritek or Princo plants in Taiwan because they can get them for $9 a spindle? I've had those go blank on my shelf too, and now I know better.
Want a long lasting CD-R? Search the spindles to find the ones that are made in Japan. Sometimes these will be on the same shelf with the Taiwan ones, wearing the same packaging, and for the same price (if you're lucky). Usually these are made by Taiyo-Yuden, a high-quality CD-R manufacturer (and one of the co-developers of CD-R technology). Look for a frosted hub for positive ID.
For archival quality, you'll need to spend a couple of bucks a disc on media that has a gold reflective layer. The standard here has always been Mitsui (now branded as MAM-A). Even their silver discs are a cut above in quality.
Oh, while I'm here. In 1996 I scribbled all over a burned CD-R with various colored Sharpies, then last year cleaned it all off with carb cleaner. It hadn't migrated into the disc at all, and cleaned off without a trace. The data was fine. Anyway, I mention this because I hear people claim Sharpies kill CD-Rs all the time, and think it's nonsense. These people probably bought the cheap-o discs and are looking for something other than their own cheapness to blame it on. Oh, BTW, the scribble disc was a Sony, made by Taiyo-Yuden.
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?
I was one of the suckers under the impression that I'd get 100 years out of my CD-R's. I have probably 50+ cd's that I'm now worried won't make it until next year. I wonder if there are any independent tests done to show which of the name brand discs will last the longest. Maybe the long term solution is for me to store everything on a very large external harddrive.
This is an old, old issue. Kodak used to sell a long life CD-R, recognizing a shelf life difference of decades between "blue" dyes and "gold" dyes. Apparently, these older (and good) dyes have been retired in favor of "optimized" shelf lives. IMHO, the issue is not technology, but planned obsolescence. What good does it do Disney (e.g.) to sell a CD (or a DVD, for that matter) thats lasts longer than 2 or 3 years? As K (MiB) says, "We'll all have to buy the White Album again."
``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
Does it matter whether or not you can hear you grandfather's voice again? Much of the stuff people want to keep is subjectively quite useless.
There exists no way of exchanging information without making judgments. --Bene Gesserit Axiom
Hehe. Let's hope that Michael keeps Slashdot archives on CD, then
+1 informative!
For greater longevity, fused silica (pottery) is best. Now, you're talking 10K years w/ no degradation.
Yes, both these technologies lack convenience. But for demonstrated longevity, they're hard to beat.
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
One Terrabyte actually, for about $1199.
Yes, I can imagine a Beowulf cluster of these...
A message from our sponsor
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...
... post it on the internet!
Magneto-optical storage uses a trick borrowed from Nature, in which geologists are able to detect the wanderings of the Earth's magnetic poles. This magnetic data has been unaffected for millions of years! A recent review of the technology can be found here, at Tom's Hardware site.
what exactly is a good noise reduction program out there?
2 words: planned obsolence. They (companies) do this for pretty much everything out there now.. Things are just not built to last like they used to be. :(
Thanks!!! First web site I found had them for about a buck a disk. Is this typical? Not complaining (since you pay for quality), but if it is easy to get them for 33 cents instead or something like that, I'd like to know.
Don't blame Durga. I voted for Centauri.
Well, maybe not, but while we're on the subject it's worth a look.
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"?
Audio CDs can lose quality consistently across a whole disc in an audible way. Obviously this occurs as you say due to the digital information being lost beyond the ability of the error correction data to reconstruct it. But it doesn't ruin every sample, so the audio is still audible, just degraded.
Specifically, I get a constant crackling on some of my CDs that have degraded in this way. The crackling only affects passages with audio and doesn't appear during silence (or relative/'analogue' silence). It's worse the louder the sound recorded. These CDs will not verifiably copy onto the computer (I have managed to save some of these CDs with EAC, but not these ones.) The worst problems I have had with certain CDRs, but I have had old pressed CDs degrade also.
pronoblem
Some expensive Ampex analog tape from the mid 70's was notoriously bad. After a few years the oxide would just start falling off.
Here is a site about analog tape restoration
The boot disks I use in work are gone after days,
because of neglect, always have to make copies..
It's a shame we aren't all using mini-discs
They have protective covers..
I have Many CD-R's more than 5 years old that still read fine. I have several over 10 years old that I can still read. Unless physically damaged I have never had a problem reading a disc. Sometimes I have to get out an older/slower/less picky drive to manage it, but I have always managed to get a good read.
James
Maybe some one should start a website that is just for archiving data, though I'm sure that there would be problems with copyright. I haven't had a big problem with my CD-R's if I don't use them, but when I use one everyday in my car it lasts just a few weeks, mostly due to my poor handling.
Some of my first CD-R's are only a couple of years old but already have *holes* in the dye layer.
I don't use optical media much now though. I prefer having a TB of disk space; far from CD-R's and DVD-R's being backup media, they tend to be used when I'm in need of an install CD or so.
Design life of a HD may only be 5 years or so, but who wants to run a 5 year old HD 10x smaller than the smallest drive you can get new for 40UKP?
I don't use those sticker CD labels, but I do write on the CD with a black Sharpie marker. Does this cause problems in degrading the CD quality?
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
I have about 50 CDs that are 10 or more years old? What are these people doing, storing their CDs in Coca Cola?
I got my first burner in 1994. Just a couple weeks ago I was playing with the newest DosBox which emulates a 386 with sound card. I wanted to play some old DOS games so I got out one of the very first cds I had burnt from 10 years ago and it read without error. I tried several others burnt at about the same time and they also read fine. All were on Verbatim media and were stored in jewel cases for the first 5 years then put in booklets and kept in a cool dry environment.
I think as long as you use quality media and use proper handling and storage precautions they will last a long time, definately longer than 5 years.
1) black dots is 1; space is 0 2) when needed, just scan it in. conversion is EASY!!! Given the fact that the error control coding implementations are everywhere, we can store a lot on a piece of paper.
^(oo)^pig~
I don't have much faith in Iain Laskey's Article after he made the following comment:
"...Otherwise any grease or dirt on your fingers can start to damage them - especially the underside where the recording surface is..."
As everyone know, you can really scratch the heck out of the underside and they will usually play fine, but put a slight scratch on the top and it's toast!
(Stolen sig) Remember: it's a "Microsoft virus", not an "email virus", a "Microsoft worm", not a "computer worm
Paper works best for archiving.
/ da taglyphs/
http://www.parc.xerox.com/research/asd/projects
My take on the best way to preserve data is keep uploading it into new formats (Tape->CD->DVD->?) to take advantage of larger storage capacities which will be necessary as stuff accumulates. Keep the old formats in a safe place so that you will have something to go back to if the older technologies last longer. When I buy a new harddrive, I copy everything from the old one and stash it intact in a safe place.
Chika Chik-ah... do-e ow ow.
for my childrens and great grand-childrens enjoyment,
Nothing lasts forever, but I'd be a lot more concerned with trying to find a machine that can read the CDs in 50-100 years from now than I would be about the data itself being corrupted.
In my country there is a consumer-protection magazine (probably most western countries have something like that) who looked into CD-R's and their longlivety.
Turns out, that 60% of the cheaper CD-R(W)s (though some 'big names' as well) were mechanically corrupted after 20 months, even when they were conserved in prestine conditions, after the burning.
So much for extended periods of time which not to worry about! Put bluntly: CD-R(W)s are crappy for archiving things, and I can't recommend libraries or the BBC archiving anything on that, unless they plan on frequent re-transferring it.
For long-term archiving, maybe one should look into the laser-ruby method, where the data is stored by 'punching' holes with laserlight (of a perticular frequency) into a ruby. It had the potential for *vast* storage, and very-long term archiving (thousands of years). I don't think it was re-writable, but the biggest problem was making big enough, pure rubies...with the current relatively cheap but yet high-quality synthetic diamant/ruby making procedures, this would be no problem anymore.
--- "To pee or not to pee, that is the question." ---
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.
(2004/02/17) in CD-Recordable FAQ:
CD-RWs are expected to last about 25 years under ideal conditions (i.e. you write it once and then leave it alone). Repeated rewrites will ccelerate
this. In general, CD-RW media isn't recommended for long-term backups or archives of valuable data.
The rest of this section applies to CD-R.
The manufacturers claim 75 years (cyanine dye, used in "green" discs), 100 years (phthalocyanine dye, used in "gold" discs), or even 200 years
("advanced" phthalocyanine dye, used in "platinum" discs) once the disc has been written. The shelf life of an unrecorded disc has been estimated at
between 5 and 10 years. There is no standard agreed-upon way to test discs for lifetime viability. Accelerated aging tests have been done, but they may not provide a meaningful analogue to real-world aging.
Exposing the disc to excessive heat, humidity, or to direct sunlight will greatly reduce the lifetime. In general, CD-Rs are far less tolerant of environmental conditions than pressed CDs, and should be treated with greater care. The easiest way to make a CD-R unusable is to scratch the
top surface. Find a CD-R you don't want anymore, and try to scratch the top (label side) with your fingernail, a ballpoint pen, a paper clip, and
anything else you have handy. The results may surprise you.
Keep them in a cool, dark, dry place, and they will probably live longer than you do (emphasis on "probably"). Some newsgroup reports have complained of discs becoming unreadable in as little as three years, but without knowing how the discs were handled and stored such anecdotes are
useless. Try to keep a little perspective on the situation: a disc that degrades very little over 100 years is useless if it can't be read in your
CD-ROM drive today.
One user reported that very inexpensive CD-Rs deteriorated in a mere six weeks, despite careful storage. Some discs are better than others.
An interesting article by Fred Langa (of http://www.langa.com/) on http://www.informationweek.com/story/showArticle.j html?articleID=15800263&pgno=1
describes how to detect bad discs, and discusses whether putting an adhesive label on the disc causes them to fail more quickly.
By some estimates, pressed CD-ROMs may only last for 10 to 25 years, because the aluminum reflective layer starts to corrode after a while.
One user was told by Blaupunkt that CD-R discs shouldn't be left in car CD players, because if it gets too hot in the car the CD-R will emit a gas that can blind the laser optics. However, CD-Rs are constructed much the same way and with mostly the same materials as pressed CDs, and the temperatures required to cause such an emission from the materials that are exposed would
melt much of the car's interior. The dye layer is sealed into the disc, and should not present any danger to drive optics even if overheated.
Even so, leaving a CD-R in a hot car isn't good for the disc, and will probably shorten its useful life.
See also http://www.cd-info.com/CDIC/Technology/CD-R/Media/ Longevity.html,
especially http://www.cd-info.com/CDIC/Industry/news/media-ch ronology.html about some inaccurate reporting in the news media.
See "Do gold CD-R discs have better longevity than green discs?" on http://www.mscience.com/faq53.html.
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
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.
If you looked after the cd's anywhere as near as you clearly did that tape, and they wernt cheap unbranded crap CD's then I expect they would well outlive the crusty old teck. Try abusing the origionals in the way you clearly do the cd's and the data won't last a second.
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......
..the CD failures were caused in part (whole?) by using stick-on CD lables. Lable your CDs with a marker, and don't worry about it.
I've got the very first CD I burned (more than 5 years old) and it still reads perfectly.
Religion is for people afraid of going to hell.
If you want it to last for 100 years then use something that has been around for 100 years. Record players have, and if they should ever become totally obsolete it would not take too much engineering to recreate a record player which would have decent enough quality to do justice to granddad's voice.
Just try to imagine what it would take to recreate a cd player and the formats needed to play it.
Transfer your tapes to digital, clean them up and have some records pressed and pass them around to your family. Donate a few to historical societies or libraries. This is another important aspect of archiving, the more copies you have distributed the better chance there is of one surviving
CDs have not been around 100 years to back up that claim and from what I have seen a small amount of damage destroys the usefulness of the disk, unlike vinyl where one skip does not leave the record unplayable.
in my front room still works, and the FDR speeches still play in tinny glory :)
errr....umm...*whooosh* *whoosh* Is this thing on ?
Whoever thought AOL would give us so many hours of amusement?
*blinking cursor*
Multiple hard drives in multiple physical locations and lots of dilligence. All other techniques are chasing the wind.
Firewire drives make this easy, although you'll have to spend a few bucks.
Popping a CD-R into the microwave tends to reduce the lifespan of a CD-R dramatically, but oh boy is the light show worth it. Remember kids: Redundancy is longevity. Data which exists in only one place effectively does not exist at all. Be sure to make two copies of every CD-R, throw the other one in the microwave for kicks, and then pray that the first one does not deteriorate. Always gamble with the persistence of your data--because fire and sparks are more important than data recovery.
When burning CDs and DVDs on a Macintosh using the built-in Disc Burner software, your Mac automatically performs a verification process after the burn is complete.
Sure, it takes longer, but it's one less step to perform and without the aid of third-party software.
Up, Up, Down, Down, Left, Right, Left, Right, B, A, START
Rense.com being cited as an authority?
Just check out his root page (http://www.rense.com)
All kinds of stuff about the world-wide Zionist conspiracy, UFOs, chem-trails, etc.
Much of his material seems to be blatently anti-semetic.
Next time use Art Bell as a source, at least I don't think he's anti-Semetic and he's probably got the same level of credibility.
I completely missed out that Rense had the story. Well, that settles is - it's TRUE. Because Rense.com carefully check and doublecheck their sources, and would never be caught lying.
What the hell is the fascination with CD-Rs?
They are small and stupid, about as useful as a floppy disk imo. Running MP3s to an MP3 player or snapping a few files for a friend are about all they are useful for.
Backup? Shite, I wish I had the patience to do regular backups on 100s of CD-Rs. DVDs are a PITA.
Need a backup? Buy another HDD and shelf it. Anything else is a waste of time.
The studies that are linked are very suspect... The linked articles mention that they use ordinary, off-the-shelf CD-ROMs. The Library of Congress study is skewed because all samples were for CDs manufactured before 1997. This is like studying current car safety by grabbing some old Corvairs out of a junkyard. (Were the CDs commercial-quality or archival-quality?)
Well, I know that hospitals use more expensive, archival-quality CD+Rs. I wonder how the results would change if they used CD+Rs like these:
Medical CD+Rs
Archive CD+Rs
The authors wish to thank AOL, Compuserve, the Thomas Register, WEBTechniques, Keithely, National Instruments, Goodfellows and Microsoft for providing target samples.
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.
AFAICT, reading all the available literature from Mitsui on their gold MAM-A discs, the reflective metallized layer _is not actually gold_. It's aluminum.
Mitsui is claiming their _special dye_ is what makes their MAM-A discs last so long, and the dye is what gives their discs their gold color. Not the metallized layer.
And really when you think about it, it doesnt matter how long-lived the reflective layer is, if your dye deteriorates. Since you're recording your data onto the dye layer -- not the reflective layer.
Just digitally remaster it, then record it on the best analog you can find. You get most of the quality, and all the durability...all you lose is the convenience, really.
How long a medium lasts is related to how well its cared for. I've seen cassettes that have lasted 30 years, but I've also seen 2 Inch multitrack tape (eg Ampex 499, around $300 for a 15-minute reel) become totally unusable after 10 years.
/.'ers)
Edison cyliders have lasted 100 years (with proper care), shellac 78's and magnetophon recordings have lasted 70 years (with proper care), reel-to-reel recordings have lasted 40 years (with proper care), and I suspect that CDs will last a long time - with proper care. Commercial CDs are nowhere near as resiliant as the inital marketing told us (who ever doubts marketing?), burned CDs substantially less so.
So, for those who STILL haven't a clue on CD care, here it is again:
1) Choose a CD that sandwiches that data layer between two polycarbonate sheets, rather than ones that have the data layer printed on (I'm looking at you, TDK). Make sure the rim of the disk is sealed with varnish (you can tell by looking closely);
2) Keep away from light (of any kind). I know geeks don't get out much, but leaving anything in the sun is bad, and the polycarb in CDs is NOT UV stable, nor is the chemistry in the data layer (if it was that chemically stable, you wouldn't be able to burn it, would you? Think about it...);
3) Store them somewhere not subject to large temerature variations (an old fire safe is good for this. I've said this before in other posts, but people got the wrong idea: a fire safe will not protect CDs from fire! It is simply a large, heavy, thermally stable box. Sure, you could use a cupboard in your basement, but most basements are not very dry, which brings up the next point);
4) Keep 'em away from moisture & humidity. Don't throw out all those old silica gel packs, they're ideal. Tupperware is a good investment for archiving;
5) Labels? Hmm, lets see, take a piece of paper covered with volatile solvents, and place it against your data layer. Anyone with half a brain could see that it was never a good idea (I've never labeled CDs with anything other than Xylene-free markers - not neat, but who cares what the CD looks like, I want my data intact). Labels, improperly positioned can cause imbalances in a CD which can make it unreadable, and gloss labels can cause CDs to become stuck in slot-load drives (iMac owner speaking from experience here, but it applies to car stereos too);
6) Never, EVER, use CD-RW for permanent backups. They are less stable than CD-R, naturally. Use some logic, folks: if CD-RW were more stable that CD-R, it would be easier to erase a CD-R than a CD-RW, wouldn't it? Its more complicated in reality, but that sums it up in a nutshell (and I've already exceeded the attention span of most
The down side of any digital medium is that in order to recover the data, you have to read ALL the 1's and 0's (or at least a good percentage of them, given reasonable error correction). Analog storage at least has the advantage that even a degraded signal is recoverable and intelligable, at least for speech applications. So while a cassette might be readable for much longer, it will start having problems like print-through, particle shedding and substrate stretch from day 1.
No medium will last long if it isn't well cared for. Its as simple as that, but unfortunately some people are even more simple.
Is there any way to get compensation if the manufacturer actually stated a life-span? even if they carefully worded it "up-to 100 years" its still misleading! Im sure we've all had carefully treated CD's fail for no reason and it varies between brand. Some CD's even explode when spun too fast (well actually all CD's explode when spun too fast but some at low speeds!) If you buy a generic brand with no markings on it do you still have consumer rights? has anyone actually been pissed off so much that they tried to get compensation? what happened?
This comment does not represent the views or opinions of the user.
duh ... the story said that he was listening to cassette tapes that were copies of the R2R tapes.
Umm... what literature would that be? There is a white paper which explicitly states that the reflective later is 24k gold.
You've never been married, have you?
Just flip the little thingy on the back of the disk that says "lock".
The puppeteer is staring into it's own eyes.
So what if a CD doesn't last a hundred years? It's still a digital medium, which means that as long as there is one good copy, you can make an unlimited number of exact duplicates with no degradation in quality.
But another points is, why would you want to keep something on CD for a hundred years? You can't walk into a Walmart and buy a record player. 100 years is probably more than the lifespan of the medium, regardless of how long each disc is expected to last.
Punctanym: alternate spelling of words using punctuation or numerals in place of some or all of its letters; see 'leet'
My 1986 International Physics Olympiad CD is still ok -- I listened to it yesterday! That was a junket from the English team, sourced from Philips/Dupont, and labeled as a CD-ROM.
It turns out I was lucky: I got Beethoven's Ninth Symphony, others got CD(-ROM)s containing just junk. But it took some 5 years before I could first listen to it -- no CD player yet!
Jeroen
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
Keep double copies of ALL tapes (video's, audio, ...)
And he'd only Use one copy to view,the other one was just used for "archiving". So when one tape wore off he just used the archiving one to renew his viewing / listening copy.
He still has everything in *perfect condition*.
Burn a CD, and store it in a place with stable temperatures and humidity, it will last for a very long time.
Pop it in and out of your computer on a daily basis, its going to deteriorate from scratches and heat from the drive slowly warping it.
CD's aren't damaged by electromagnetic waves except at incredibly high levels. A magnetic tape however, being within a couple feet of a television will cause noticeable degradation within weeks or months. For long term archival storage, background radiation will start having a noticeable effect on magnetic media, while CD's will just sit there.
isnt that whats the hottest stuff on the backup front these days? minidiscs are based on that system from what i have read. you write by laser and magnet and read by laser.
anyone knows the lifetime on these?
comment first, facts later. http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm
Real men write stuff that the rest of the world wants to copy.
Cassette is the WORST FORMAT EVER RELEASED. It is the lowest quality, and the most error prone, even more error prone than r2r AND the fidelity is terrible. If you HAVE r2r then dear god, copy it to some high end format, not cassette.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
In addition to backup, you need to do something to insure the file is still readable and still has the correct bits. A backup of a corrupt file is still corrupt. Bitrot can be silent.
I'm sure freshmeat will have a few apps that will do integrity checking, aide comes to mind.
Anything is possible given time and money.
I read through the +5 comments and didn't see anything about Flash memory. Is it any more reliable than a CD for long term data storage and if so, why not use that for the really important and/or sentimental things?
I did in fact click the link and read the "study". From a seemingly fair quantity of information, I was able to conclude... nothing. I'm convinced that statisticians and technical researchers need a bit more training about how to communicate like human beings.
Unless I'm mistaken, they were baking CD's at 175F to simulate aging? I'm pretty sure that if you were to bake me at 175F for a length of time, you would arrive at different results than actually allowing me to age.
The actual life of any specific item depends on many factors: manufacturing quality, manufacturing materials, storage, number of plays, etc.
So, while it is fair to say that "audio tape" is a relatively short-lived, fragile medium (based on the average "audio tape") it is not unusual to have tapes that last 30 years without noticable degradation. I've had tapes that didn't survive the first pass through the recorder, because they were made with crappy glue holding brittle magnetic bits. I have tapes that I've kept in a box for twenty years that are just fine.
You'll find the same thing for CD's. If you use good quality CD-Rs, and store them correctly, I have little doubt that 100 years is a reasonable expected lifetime.
And as others have already pointed out, if the recording is really important, make multiple copies, and then make new copies from the old before they degrade. In this case, CD-R has it over tape, because each generation of tape gets worse, while each generation of CD-R is identical to the parent.
lets face it analog is better sounding and more durable than digital. it is a dirty secret but so true. if you doubt this find an audio shop that has home audio tube amps/preamps and a turntable then listen to the same cd and lp. the lp wins everytime. waveform vs blocks. what will really blow your mind would be to find some low 1 to 8 watt single ended triode tube amps and some vintage klipsch say some belle's or khorns and you won't believe the sound.....
ANALOG OWNZ
Digital content lasts for 5 years or forever, whatever comes first.
I have discovered a truly remarkable proof for my post which this sig is too small to contain.
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.
I have CD I made with my original 1x cd burner that still function perfectly
Question. Would a CD-RW last longer since the process of recording is different? CD-RW discs have pits melted onto them.
I don't know if this would be true or not. Just something I was thinking about. If anyone knows if this is the case please respond.
OK, so I'm dating myself, bigtime, but years ago, before there were CDs and DVDs, there was this great video storage medium called a "Laserdisc." You couldn't record on them, and they'd hold, at best, an hour on each side (less in CAV format), but they were decent for keeping movies and concerts around - they had fairly good audio quality, for the time.
:( The first discs to die were my ABBA videos, and the Linda Ronstadt concert. Thankfully, I can still watch at least most of Xanadu, the ONJ "Physical" concert and Tank Girl.
I bought a player, and a bunch of discs. After a few years, I noticed that the discs were starting to crap out, going staticy and noisy. Inspection shows that the aluminum inner layer, upon which the data was recorded, was deteriorating, turning to aluminum oxide. Seems the plastic wasn't really able to keep all the oxygen away, as claimed.
Net effect is that I have a player that may be usable, but darned few discs that are still playable. I've long since recorded all the discs onto VHS tape. I had hoped to be able to watch the movies, and concerts, time and again, from purchase through retirement. Fat chance
Don't believe a word about CD's longevity. Even if treated with the utmost care, they are not likely to last ten years, and five years from home-recordable media would be pretty good.
Lemon curry?
This sounds dumb, but I find you can worry yourself to death about this. My latest theory - only keep the original media, and don't worry about it. If you use it, you will keep it on current media (LP to tape, then disc for music, diskette to HD for code) through natural usage. Or, others will (radio stations, collectors, servers, P2P, FTP sites, URL's, i-net archive sites). If you don't use it, and nobody else does, who cares? Mourn its loss and attempt to recreate or move on.
My neighbor has a michael jackson casette which was degraded over time. The line....
"He He He The way she turns me on".
now sounds like
"He turns me on".
CDs would have just lost the whole line or song.
Many of you know this but some of you may not. A lot of people put too much emphasis on protecting the bottom of a CD. The real fragile part is the label side. With a coin you can easily scratch off the label side and see right through the CD. The dye lays on top of the plastic and is covered by silver and the label paint. If the bottom gets scratched you can polish the scratches out. There's a video game shop here that polishes CDs for $5.
(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?
Occasionally they post stories here quoting 'Analyst' Rob Enderle.
The distributed backup system you just described is also followed by the Lockss library/publishing model.
hm, all their other papers didn't make any mention of it. shrug.
still, doesnt matter if your metallized layer lasts 20 trillion years if your dye layer degrades, since its the dye layer which holds your data. phthalocyanine (organic dye) won't last forever.
i suspect M-O media will last longer.
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.
That report from the library of congress pertains to PRESSED audio CD's.
I don't know about you, but nobody else in my neighbourhood has a CD pressing unit. We all used burned CD's, which ARE NOT THE SAME THING!
I say go with Iomega Zip disks, I...
hey, what's that clicking noise?
You can have my cynical agnosticism when you pry it from my cold, dead logic.
It's the nature of digital to resist decay because the difference between a one and a zero is BIG. That makes it hard for an individual bit to change state from a one to a zero or vice-versa.
Analog tapes, on the other hand, are in flux -- they change while you stare at them, only it's hard for you to perceive the change. For instance, even if there was no signal degredation, we can bet your tapes have stretched, as you played them, and in the boxes they were stored in, and that therefore the pitch of your grandfather's voice has changed.
They've probably drooped on the reels a little, and therefore his voice goes up and down, but so little that you wouldn't notice.
If you're recording in a non-lossy digital format, you're safe from that. Everything will be pitch perfect, but in the unlikely (at any given time) and yet innevitable (over a long time) event that bits change in your digital form, you'll gets some pops, as bits change in random positions.
In an eight-bit sample-size example: 10101010 might change to a 10101011 or a 11101010 -- the former would be inperceptable, but the other would be a big smack on the sound.
The real problem here is not the degradation of the non-lossy copy of your grandfather's voice, it's the sector boundaries, the directory of the disk -- It's the stuff that lets your computer FIND the data and interpret the data. If you get a bad sector on the disk, the data as sound is essentially still perfectly good. But most systems would give up on a disk with an important bad sector.
What we need is a way to write bit-streams to CD or some other medium where we know the medium will be readable AS BITS in 20 years. Sectors aren't important if the system is simple and the player is smart -- allowing you access to the data even though the stuff describing where it is is damaged.
Most software for reading (ie. OS software) just give up. Most lossy systems don't gracefully handle bad data in their files. Most storage systems don't store the data redundantly (you'd need three copies of a given bit, or a mathematical checksum which allows you to compute bits based on three factors to recover data as it drops out). Most media formats have short life-spans.
It would be great if someone, say the library of Congress, would work with a good, smart technician and the technical community to come up with a simple format which is robust, and then agree to use it as an archive system for some number of years.
A CD or DVD-based system seems like a good starting place.
This is actually a big deal. Linguists die, and ten years later someone goes through their drawers, finding tapes of languages dead longer than the linguist, and those tapes are turning to muck. We can get back some of the lost history, but not most. Likewise, as we take a lot of digital pictures, now, those will be lost to history in 20 years.
Academics need this like crazy, and so do grandchildren.
Is that I can still read data from Iomega Zip disks that are 6 years old, yet can't read CD's I burned 6 months ago. For some reason, the perils of magnetic media and Zip drives never came true for me.
What really irks me is that CD-R was sold to the public as a way of _permanently_ archiving data. Once written, it was supposed to be permanent. The non-magnetic, non-rewritable nature of the media was supposed to prevent accidental overwrites and erasures from magnetic fields.
Top Ten reasons to love CD-R/CD-RW:
* - yes, these are the recommendations that came with a 2004 Toshiba laptop regarding making CD's.
The society for a thought-free internet welcomes you.
Chiseled Stone Tablets...
Just don't throw them to the ground in anger like Moses did. They will shatter and you will be screwed.
Sign up for 1000 Google gmail accounts and use it for long term archival purposes by mailing in large attachments. Let them do the work for you!
What is it with these silly "pdf warnings"?
.pdf right there.
It is an open format, with rms-free viewers. And for the opening of an external app, can people not look at the link? It says
If so, where does it end? Can we prep CD-R media to store them stably below 0 C? Is stabilized storage in liquid nitrogen out of the question?
In a related issue, this can be a huge challenge. Not to be flip, but paper is in many instances a more reliable and persistant repository. In some industries (e.g. boiler valve castings) a part may be in production for 50 years with a mean time to revision of 10 years. How many CAD systems and versions of CAD systems would a corporation go through in that time starting today? In the automotive industry they "refile" (open and resave in new version) zillions of CAD files each year. Forward compatibility is fine one or two versions...but get a bit chancy after that.
All this is an example were rapid changes in technology are as much a headache as a blessing.
When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
I've found the same thing with my VCDs I make. If I burn them any faster than about 4x I get a CD that "skips" in my DVD player when played. (Not skipping per se but it pauses for a few seconds, rebuffers, and plays again, very very annoying towards the end of the disc.)
VCDs are incredibly sensitive to errors because they use are mode 2 CDs. That is the error correction bits are removed from the CD blocks in order to provide more space on to the disc. Error correcting is relying upon the error correction inside the mpeg stream itself.
Whos to even say that the file format will still be supported long into the future as well.
Makes me wonder about thoses old Apple//e games I used to have on 5.25" discs.
I miss Hard Hat Mac!
Well I have some experience with old MO media. I've got a NeXT cube with the big, heavy, honking 5 1/4" MO drive. I have several MO disks to go with it and the oldest disk has a copy of NeXTSTEP 0.8 from the late 1980's. The drive itself is finicky as hell and very sensitive to dust, but after a good disassembly and dusting of the intenal components, the sucker boots right up. Quite impressive after all these years.
I tried every decent and legal way I could think of to resolve the issue w/the business before I rented the chicken suit
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
You just have to make a RAID-5 array of CD's with every CD you want to keep, so when a part finally fails you can reconstruct it!
At last, I have found a use for the RAID ports on my mobo!!
You're not old until regret takes the place of your dreams.
Okay, maybe I am overstating this but think of the things that have come and gone in the past thirty tree years. In 1971, the standard product to deliver music was the LP or the 45. A lot of people used 8 tracks for their cars, and the cassette was popular for recorders but not too many people had stereo cassette recorders. Quadrophonic was the "in thing."
Most Audiophiles recommended the Dual 1249 manual turntable mounted on a granite block dampend by rubber. They also felt that tube amps were far superior to transistor amps because the sound was "wetter." Altec-Lansing speakers were the very best and you needed a Fisher reciever and a Marantz amp.
Computers were something huge, they did data with reel to reel magnetic tapes or punch cards or punched paper tape. Baudot was as common as ASCII. Teletypes and VDT's were the common input devices. The very few floppy drives out there were 8' units.
So thirty-three years later, getting the data from that day's generation of computers to today's computers would be difficult to nearly impossible. The "quality" of the data would be suspect not because of the retention quality of the media but because the data itself would be pretty weak in comparison to what we would collect today.
I have no doubt that in thirty three years we will look back on 2004's computing equipment in the same way. We are in the infancy stage still. Computing has a long ways to go. We'll probably be considered "BQ" (Before Quantum) by 2037!
Those CD's and DVD's will be antique. Something much smaller and faster with more storage will replace them.
Tape seems to tolerate degradation better because if a few magnatic "bits" flip, it won't make much difference, mostly just more background hiss. However, if a digital stream loses a bit or two, the current algorithms cannot recover very well.
What is needed is special encoding, reading, and algorithms that are more tolerant of degradation. However, it will probably take up more storage space, but that may be the tradeoff for longevity.
Tape tends to have redundancy in the lower frequencies, and this is partly why it seems less fragile. Perhaps something similar on the digital side can be done.
I notice that our VCR tapes are more kid-proof than DVD's. The kids play with both innappropriately, and the VCR tapes have about a 3-to-1 survivle rate over DVD's. I would have never guessed this without seeing it in action because VCR tapes have seemingly fragile moving parts and more parts. Go figure.
Table-ized A.I.
And post on Slashdot.
No, the dye won't last forever. However, in harsh conditions it lasts noticably longer than most alternatives. Or at least, it is claimed to last much longer in, say, the direct sunlight challenge.
Cassette is the WORST FORMAT EVER RELEASED. It is the lowest quality, and the most error prone, even more error prone than r2r AND the fidelity is terrible.
Guessing you have never even heard of 8-track tapes, much less listened to any.
2) Rip your audio as WAV or RAW with no compression at all (this is critical)
3) burn A LARGE NUMBER of identical copies. 5 isn't a bad idea, 7 or 9+ is great.
In 50 years, here's what'll happen. You'll find these disks. You'll send them to some data-recovery house who has one of those antique CD thingamajiggers. When they go to recover, they'll diff all N cds, and for each bit, weigh the results of all CDs and store the majority "vote". When they're done, you'll have your original CDs, with still some bad bits.
Here's where the "not compressed" part comes in. When you get it, you won't have to find an antiquated MP3 decoder, since the data is just there; raw amplitudes. If a bit is wrong, you've corrupted exactly one sample, which will show up as an instantaneous spike or dip. It will be trivial for a filter to clean these up (you can do this today). They key is that compression reduces redundancy; don't compress, and you have highly redundant (and hence robust) data, a la analog.
--dan
This posting is provided "AS IS" with no warranties, and confers no rights.
Why don't you axe your childrens if they wants the recording in the first place.
...We can't bust heads like we used to, but we have our ways. One trick is to tell them stories that don't go anywhere. Like the time I caught the ferry over to Shelbyville. I needed a new heel for my shoe. So I decided to go to Morganville, which was what they called Shelbyville in those days. So I tied an onion to my belt, which was the style at the time. Now, to take the ferry costs a nickel. And in those days nickels had pictures of Bumblebees on them. `Gimme five bees for a quarter' you'd say. Now where were we....oh yeah, the important thing was that I had an onion on my belt, which was the style at the time....they didn't have white onions, because of the war, the only thing you could get was the big yellow ones...
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?
;)
The chances that an error will go uncaught is absolutely none if you use a simple software hash (sfv, par) to verify. These take up only a few kb. However, without recovery files (par does that too), they only inform you. So the chances that an error will be unrecoverable is slim but present.
First you have the raw data disk. Then you have the error correction on CD (~10% I think). Then you can do software error correction (PAR2 would be ideal). If you need more security than that, your only real choice is multiple copies, preferably at alternating lifecycles.
Let's take an example with two disks. The estimated lifetime is 5 years. You would then burn one disc every 2,5 years, at all times having two copies, one less than 2,5 years old, one less than 5 years old. With PAR2s you can even mix and match so that even if neither disk is recoverable by itself, the combined set is.
It's all about math. If each disk is 99% sure, two discs are 99,99%(+, due to cross-recovery), three 99,9999%(+)... you can't get 100%, but you can get arbitrarily close. All depends on how important it is to you.
Personally, I wish you could build a RAID system across friends (or would that be a WSAN or something?). Simply have 4-5 of my friends with DSL dedicate a gb to my encrypted files, they wouldn't all have problems at the same time... Or if they do, I think the bomb that took out our city has me worried for other reasons
Kjella
Live today, because you never know what tomorrow brings
Like Windows?
Just kidding!
Just because it CAN be done, doesn't mean it should!
Just use a MO (Magneto-Optical) drive to store archival stuff like this. It has the longest shelf life, is very reliable and virtually indestructable.
There is a good article about magneto-optical storage at tom's hardware. An interesting idea, which may be the best option for long term storage. I've never used it myself, but am considering using it to back-up old VHS x-mas tapes and such.
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.
I do the same thing. Ohh, I tried backing up my data at various points in my life.
.. 1TB or so. These days, a terrabyte isn't that much anymore. Every so often, I buy the one-step-down-from-biggest drive (for the price.)
I've used floppies, and ZIP disks. I've used CD's and DVD's, and I have a DLT drive I can use to backup a measly 40GB uncompressed data to if I so choose. None of these options are really as good for me then just to simply keep buying new hard drives, and shuffle the data to the new drives as they are purchased.
It's not like I have THAT much data to store. Maybe
In this manner, I never really have to worry about media degredation.
- It's not the Macs I hate. It's Digg users. -
It really is frustrating when "experts" issue dire, yet vague, warnings about what you should NEVER do ("do not use solvent-based markers") and then don't follow with *specific* suggestions for what you *should* do.
I don't know what kind of marker would qualify as NOT solvent based. Alcohol and water are solvents, of course. Maybe they are included. Maybe not. Maybe one is but not the other.
The Sharpie marker beside me doesn't mention solvent or non-solvent on the label and smells like cherry Kool-Aid with the cap off. So, what does it use? Is this exactly the type of marker I should use, or is this what they're saying I shouldn't use? If the latter, what -- specifically -- SHOULD I use?
Arrgh. Thanks for the expert advice.
"Those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded."
actually having worked in the healthcare field I can say from experience that healthcare uses M-O for the past 10-20 years and 9-track before that.
anyone using dvd-ram is a very very very recent thing. i cant imagine cash strapped healthcare sites dumping their huge M-O investments for brand spanking new DVD-RAM.
To change the topic entirely, did anyone else think the Michael Jackson South Park episode was kind of lame?
Shop as usual. And avoid panic buying.
You know if you run across some old tapes and they are falling apart, you can literally bake it back to health. This process recombines the chemicals in the tape, so they will be usable for another 10 years.
Always at 130 degrees, bake:
1/4" tape - 1 to 4 hours
1/2" tape - 2-5 hours
1" tape - 3-6 hours
2" tape - 4 to 8 hours
To check if it's done, use a white, clean cloth cloth and swab it on part of the actual tape. If a lot of magnetic oxide comes off, bake more. Tape is done once cloth is wiped and is mostly clean. (Some residue is normal.)
http://cassettefetish.com
if your story was a tiny be longer it'd be BOFH material, except, somehow the "cd dust" must arive in the caffeteria the bean counters eat at, etc..convienently ..just before an audit..
It was just kids.
Anyone know why you should store CDs upright instead of horizontally? I can't think of any obvious reasons off the top of my head...
CAN they build 100 year CDs, and what would they cost then? A dime more a disk, a quarter, what? Or is it too late, because DVDs are so common now, and other storage media coming soon?
me/ don't even have a burner yet....rats, I still use floppies.....
duh... everyone knows that if you go around the edges with a green magic marker that the CD will last forever.....
=)
stephen
It's not just CD-R's that have been over-trusted, as the Library of Congress report makes clear. In the 1980's advertisers said that CD players were better than phonographs because a music CD, if handled carefully, would never wear out. At the time, I believed them.
But about six months ago I was shocked to discover that several of my treasured music CD-ROM's had visible damage. These were commercially-recorded disks bought in the late 80's and early 90's, that had always been stored indoors in their original cases. None of these had ever been ever been taken traveling or stored without heat or AC; certainly none of them had been subjected to stress, except the stress of being played.
The worst of them had what appeared to be both pinhole burns and flaked spots in the metal film. The very worst of them were some of my prized Deutsche Grammophon classical disks, manufactured by Polydor International. My collection is much smaller than that of the Library, but I had more than one disk that looked like Image 1 in the Library's report.
Needless to say, I have been taking better care than ever of my old vinyl LP's, some of which are over 35 years old and still in good condition.
I figure by 2030 or so my 6-digit UID will be something to brag about.
The obvious answer is redundant, on-line, off-site backup.
It's even within the the reach of most of us (that's us, the cutting-edge Slashdot readership) - you can daily back up 1 or 2GB using ADSL, friends' PCs and a bit of scripting.
The future lies in duplication and redundancy. Data storage and bandwidth are getting so cheap that I think in a few years everyone will be using on-line, off-site backups. Some peering with friends, some with other businesses, some with specialist companies.
Intellectual Property
Intellectual: of the mind
Property: that over which one has control
That's it, I'm starting a bonfire tonight to burn all my CD's. What's the point of backing anything up if it only lasts five years? I know my hard drive will never let me down and go 100 years. Oh wait...
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Is it normal or good for us to be able to actually here voices or see ancestors from 100+ years ago?....that might stagnate our civilization! It's bad enough movie producers can't think of new ideas and are rehashing movies and television shows of the last 50 years. I've even seen the THIRD rehash of some of the same old crap. Now we're able to recall every mundane thing from 3 generations ago with perfect clarity....eeek! Let the bits rot I say!
You think that's something to have a recording from 1971? I've got hours and hours of tape from a group of guys in 1963 through 1967; it doesn't just have their voices but they sing, too! Songs about advice with girls (She Loves Me, I Want to Hold Your Hand, Baby You Can Drive My Car, Hey, Jude), recreational drugs (Lucy in the Sky with Diamonds, Strawberry Fields), politics (everything else, basically). And my aged dad, now a granddad himself, has tapes and "LPs" (larger than a CD but with better quality audio; infinite bits, ya know) of dudes from the 1940s and 1950s! Whoo!
Damn kids. 1971 is a benchmark for longevity?
-- @rjamestaylor on Ello
The nat'l library of Denmark is now copying CDs (pressed, not burned) that they archived in mid/early 80ies. They have an archive of 25'000 CDs - never played, never exposed to light or heat. Just last week an article (danish sorry) about it. Select quotes:
On some there was an oily creamy layer on the bottom side. On others there were lots of needle thin holes in the disk - you could actually see light through. Still others had the different layers separating, with water in between [...] We've seen the phenomenon in the very first generation of CDs from the early 80ies. In a box of 50 CDs from the same year there were maybe two dissolving, so lifetime must depend on manufacturer and material
Any sufficiently advanced libertarian utopia is indistinguishable from government.
>> Cassette is the WORST FORMAT EVER RELEASED.
> Guessing you have never even heard of 8-track tapes, much less listened to any.
No, I suspect [s]he just meant "Compact Audio Cassette" or whatever the official designation is. That's certainly what I think of when I hear the word "cassette". If I mean 8-track I say "8-track". I mean, dictaphone, DAT, Elcaset, and DCC are (or were) all technically cassette formats too, but I doubt that the poster was deriding any of them.
Not that I'd advise dictaphone cassette as an archival storage medium, mind you.
A lot has been done in coming up with good general purpose utilities for compressing files (for efficient transfer over communications links). For archiving, though, you want the opposite. You want a good expanding algorithm (error correction coder). If you are interested in archiving on a media that may slowly degrade, you may be willing to give up capacity for error free recovery. And here is the key point - what form do the errors take on a degrading CD? Are they random errors sprinkled over the disk, or block errors, where an entire sector may be lost at a time? (Of course if the entire CD fades out, you're screwed no matter what coding you do.) It would be useful to have a general purpose utility like gzip (say, gecc and gunecc) that applies a variable rate convolutional coder to files that need to be recovered in the face of bit errors. The CD medium inherent has coding, but you certainly could use more if your data is important to you.
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."
I stored all my important data on gold records like the one on Voyager. Estimated shelf-life was a billion years. Yes, that's what they really estimated.
I do remember being amazed as a kid that with a needle, a piece of paper, and some tape I could actually hear what was put on a record.
Put your data on punched paper tape and store it in little stainless steel canisters taped shut so they will last really really long. But then you will need to find a paper tape reader in 100 years...
You'd be surprised. 8-track actually saw use in commercial radio up until the early 90's...They sucked and were error prone, but the sound reproduction wasn't bad--it was an idea vehicle for sound bites and other disposable crap. As opposed to cassette, which never made it on the air anywhere except college radio.
The 8-track carts got replaced by DAT and Mini-disks---the only place those media actually got a fair shot.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
Not enough imagination. Encode it into your own DNA. Hey! File sharing was never this much fun.
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 . . .
These use a dark blue (Super AZO) dye and are said to burn at up to 52x. The label also gives a 100-year archival life.
"These tapes are copies of reel to reel recorded in 1971, and they are still in excellent shape."
Really now. And in exactly what kind of environment did you keep these reels in? Relatively unmolested? Out of the elements? Reasonably protected? Why do I have the sneaking suspicion that if the CDs you're maligning were kept in the same conditions, they'd be equally- if not better -preserved? Let's subject your tape reel and a CD to the same amount of general wear and usage and see which one lasts longer, kay?
Sorry man, I gotta say you're full of bullshit.
You need a FREE iPod Nano
You can still find boxes of Kodak Gold Ultima discs at computer swap meets in Australia from time to time. They look authentic, and the media reports itself as "Kodak Japan" when burned.
With storage capacity increasing faster than the need for it, why should this be a concern? All my backups are on offsite HD's. Sure, HD's don't have a long shelf life, but so what? All the data I ever had on my Amiga, about 360MB, was a folder on my Pentium Pro 180 machine. All the data on that machine is a folder on my current system.
I just move it along to the new storage, every few years making fesh copies onto new HD's which swallow all of it with nary a burp.
So longevity has never been a concern with me, because the migration happens much too often for shelf life to be a concern.... and HD storage is stupid cheap these days. And I have everything online as a bonus.
Some expensive Ampex analog tape from the mid 70's was notoriously bad. After a few years the oxide would just start falling off.
.... :(
The master tapes to the music soundtrack to TRON almost devolved into 'Pure Tree Sap'. Thankfully, Wendy Carlos was able to rescue it for its (legitimate) CD release--of which I own a copy.
Oh dear, it looks like it's out of print (after TWO years!?!?) so I didn't bother with an Amazon link to it--3rd parties are offering it for sale there at the time of writing this post for $28.50 to $59.99
I know someone who accidentally bought CDRW media instead of CDR. Turns out if you make use CDRW media just like CDR, and make a single session, closed disk, you can't write over it, accidentally or otherwise -- I tried, with several different programs.
~REZ~ #43301. Who'd fake being me anyway?
...about magneto optical storage, or MO drives. Alot of scientists and government agencies rely on them for serious archiving.
Shelf life of around 100 years if I'm not mistaken.
...about 5 years ago. it bombed. there was also the superdisk. it bombed. now we have usb flashdrives with generic USB bulk storage drivers.
they may not be any longer lasting though - the only answer is archive and periodically read and rearchive to the latest storage medium.
And me, Joe Schmoe asks for my stuff back but since I am not Linus, nobody gave a shit and so the BOFH rammed it right into the bit bucket after a short grace period.
to store pr0n. I can't wait to see what lickpussy.jpg looks like in bar code format....
You don't need a vinyl turntable, unless you're archiving for the library of congress or something. Just get a decent one with a decent needle. Sure there is degradation over time if you play the record a lot so if you really want to keep something around that you listen to a lot, buy another copy for listening to. But even if you beat the hell out of your vinyl the basic signal will last your lifetime at least, though it will sound crappy if you scratch it up. I have 78s from the 1930s that sound fine (for 78s recorded that time). With normal vinyl if you change needles often and have a decent turntable (and set the tonearm properly), it will last a long time. If the vinyl is truly for archival purposes, I suspect you are not playing it at parties every weekend and such; it will last much longer that way of course. A record that will be played ten times in as many years does not need to be played on a laser turntable. Those things are cool -- and if I had that much extra cash perhaps I would buy one -- but they're not necessary for most users, even those of us who want our grandchildren to be able to hear the shit we used to listen to.
No, I suspect [s]he just meant
Don't like your odds on it being a she :)
My spelling isn't bad, I'm evolving the language
I guess he said that a long time ago. Today there are better ways to back up your stuff - just share it on P2P. That's where I store my movie collection.
Future Wiki -- If you don't think about the future, you cannot have one.
the 3- and 5- years olds who have learned to load them in almost properly to the CD player.
> It's the glue. It can corrode the top layer.
An additional problem with sticker labels is that they mechanically deform the media. It is then more difficult to read it. When this adds up with other aging effects, the sticker-labelled CD "dies" earlier than non-labelled CDs.