Slashdot Mirror
NIST Releases Study Of CD/DVD Longevity
dirkin writes "The National Institute of Standards and Technology has released a preliminary study of the potential lifespan of CD-Rs and DVD-Rs. The PDF study is here. A good starting point for deciding what type of media to purchase to keep those backups and photos kicking around longer. (You DID buy the silver/gold alloy phthalocyanine CDs, didn't you?)"
Well - if you recall tape drives were the "big thing" in backup about 5-10 years ago. I have looked at 10 year old tape backups & they work just fine. Maybe we need to trust good old reliable tapes. Or the other (faster) solution would be external hard drive backups.
===> An eye for an eye makes everyone blind - MG
This doesn't tell us much. It's almost a teaser. "Are you going to die tomorrow? The answer may surprise you. Stay tuned for News at 11." I have some CDRs that stopped working within days and others that have lasted over 4 years now--same brand from the same spindle even. I wonder if the full Dutch article gives specifics or if they found _any_ CDs that were still working fine after twenty months. The teaser seems to suggest that they're all terrible. I do know that I get fewer duds now that I use Toast than I did when I used "Easy CD Creator." Beyond that, I don't know anything that makes a difference. CDRs stop working. DVD-Rs are crazy fragile. Hard drives fail. Paper burns. Maybe my data wasn't supposed to last forever. Alex.
I've always wondered if this is actually true or not.. I have yet to see any actual evidence to back up this claim.
It doesn't really matter how fast the reading laser moves along the media, so why would it matter how fast the recording laser moves?
DJ kRYPT's Free MP3s!
What speed was used to write the CDs?
Were they all stored in the same place?
Were they all burned by the same CD burner?
Were they all burned from the same source (a single CD, hard drive, network, etc.)?
30 CDs sounds like an epidemic, but since they were all burned at the same time twenty months ago, there could be a lot of other reasons why all of these discs would go bad. If they were all burned at the same time, then they're effectively talking about one batch, regardless of how many different CD-R brands were used in that single batch.
Does the Dutch article cover this or is this just a scare story?
Don't forget to have one or more off-site backups (encrypted in case they are stolen). I keep one off-site backup (on CD-RW) in town, at a friend's place, and swap it for a fresh backup every time I visit him. (Be sure to offer to do the same for your friends.) An out-of-state backup gets refreshed every time I visit my folks.
It's peace of mind knowing that if, heavens forbid, anything catastrophic were to happen to your place of residence, or if burglars were to take your computers and disks/tapes, then you would at least not have completely lost all of your critical data.
So instead of worrying sbout the CD falling apart, you have to worry about mechanical failure. Unfortunately, that can happen from just sitting around, especially in something so fragile as a hard disk drive.
01101001 01100001 01101101 01101110 01101111 01110100 01100001 01101100 01100001 01110111 01111001 01100101 01110010
With the study subjecting discs to extremes to cause them to fail, they've shown relative tolerance to certain conditions, but we still don't have "burn to these CDs and keep temp between 60 and 80, RH between 10% and 50%, and light to a minimum and they're good for 10 years" kind of numbers...
500GB of disk, 5TB of transfer, $5.95/mo
I have some Kodak Gold CD-Rs stashed away for archival masters. I have no idea how long the DVD+Rs and DVD+RWs will last.
Mea navis aericumbens anguillis abundat
...I guess I'm the oddball here. I've never thought of any of these media as permanent storage. In fact, I learned quickly very early on that all are susceptible to wear, damage or degradation. CDR/W and related tech are more a bandwidth-saving item or convenience item than anything else to me. The things that I need to save, I move to newer formats, usually multiple copies if it's important stuff.
I've yet to lose data to media degradation, however I once lost some important accounting data to a hard drive crash, followed by two ZIP disk backups that were killed by "click-death". One in a billion shot, I guess. Well, I didn't exactly lose the data, I had hard copies on paper, apparently the only semi-permanent storage media that's trustworthy.
Fred
"A fool and his freedom are soon parted"
-RMS
It doesn't matter whether holographic storage is here now, or ever. I have a large collection of CDs on spindles that will surely go bad within the next 3-5 years, but I'm not going to sweat it. If you figure that at least 50 CDs fit onto a single high-capacity DVD (e.g. blu-ray), there's no way I'm going to worry about it.
However, the same doesn't apply for everyone. Many information-intensive companies are constantly struggling to keep up with the latest technology, spending big $$ on data retrieval. Thousands of tape backups aren't quite as easy to read and consolidate as a bunch of personal CDs. I guess the story here is that most people think CDs are a permanent storage medium.
The biggest issue IMO isn't the media, but the readers. So what if your CD-RW is still readable in 20 years if you can't even find a CD-ROM around to read them with?
I still have tons of 5" floppy disks around, and I'm sure the data on them is usable, but getting it off is another story.
did you ever go to the store and pick up a cheapo blank and a super high grade? you can feel the weight difference. you can also tell with older movies that are sold for under $10... they always weigh nothing. VHS tape is magnetic media (like audio tape)... generally speaking the heavier it is the better the quality. the higher quality ones also will last through more playings/recordings. i am not sure if either are better for archiving though.
with CD-R media i have heard some claims that the black ones are good (look like a playstation game) if they will go to people that have a tendency to leave disks all over their desk... the black plastic lens keeps harmful light off the media surface.
test brands yourself... leave a few on your dashboard through the summer and see what the sun and temperature swings do to them.
(NOT a joke post)
Is it true with many things that reflect light, that the less light it throws back, the more it ABSORBS?
--meaning here probably, that absorbation is what degrades the medium.
I mean, I've had both "dull" and "blinding" discs, (some light-green one's that basically didn't shine at all once "shone on",) and the EXTREMELY reflective one's, that would practically blind you, to some extent.. --I mean, when angled towards a tungsten bulb, or flashlight, whatever..
-Get the drift? --Maybe this is of some importance, don't ask me.. I always go for 'the shiny' one's; as I've suspected them to be "better"..
A horse can't be sick, you know, even if he wants to.
Is the data really gone, or is it simply the reader that can no longer handle the tolerances? Are the dots truly gone, or just harder to read? It could be that archivists and the rest of us need more tolerant, but slower-reading devices for when we have flaky discs.
Really, the big advantage stone tablets have is huge amounts of redundancy, but a very small amount of actual data. DVDs could have multiple repetitions of the data on different parts of the disc for fault tolerance.
Ooh, a sarcasm detector. Oh, that's a real useful invention.
I personally believe tapes and tape drives are a big con-job nowadays.
They may not be great for home backups (they never really were) but tape is definitly NOT a con-job. LTO-3 is 800GB per ~$150 tape, disk can't touch that, and they backup at up to 160MB/s, again a single drive can't touch that. The only reasonable solutions to backing up LOTS of data are tape or farms and farms of drives which are offsite with a VERY high speed network connection and which are write protected while not being backed up to. The latter can be done but it generally makes tape look cheap. Again for home use there probably isn't a lot of use for tape (I backup my machine by HDD as well), but for my clients I can't imagine using anything other than tape as an offsite/archival solution.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Umm, 'scuse me a sec..
I have a 133 megabyte full height 5.25 Maxtor that is 20 years old, and a 44 megabyte miniscribe that is 22 years old. I saved them back from the days when they were GOLD to me.
Like a moron, I traded a 100mhz dual trace Tektronix scope for the 133 meg drive. Now it sits on the floor in the closet. But guess what?
The drive STILL boots and runs. Yep, it's loaded with IBM DOS 3.1 and I can still play some of my old Sierra games on it.
It's worth squat. But after 20 years of banging around on the floor as I moved several times, it still boots and runs.
I can't say that for CDR's I burned two years ago. Most of them over 2 years old are riddled with holes, like moths eating wool..
I DO NOT trust CD or DVD media for long term storage. Piss poor media if you ask me. I wish they had never invented the damn things, I put lots of important data on them over the years just to go back later and find it ruined and gone forever.
CD and DVD is a BAD technology. It's time to abandon it and reinvent the wheel..