Up To 10% of CD-Rs Fail Within a Few Years 317
Whatever you think about the likelihood that a new kind of DVDs could last for 1,000 years, this note from reader crazyeyes should give you pause about expecting current CD-Rs to be reliably readable for decades. TechARP found a failure rate near 10% for CD-Rs recorded 7 to 9 years ago, after storage in ideal conditions. On some, one or more individual files could not be recovered; others were not reliably readable on two separate drives. "In the past, hard disk drives were small (in capacity) and costly. To make up for the lack of affordable storage, many turned to CD-Rs. As it became common to store backups and personal pictures, videos, etc. on CD-Rs, the lifespan of these discs became a concern. According to manufacturers, CD-Rs should last for decades. Some even quoted an upper limit of 120 years based on accelerated aging tests! That sure is a long time, isn't it? But will CD-Rs really last that long?"
Depends on the brand (Score:5, Interesting)
I've experienced this myself lately with a bunch of disks that were now useless. It was cheaper off brand disks that failed. The irony is at the time I got them, they were the ONLY disks I could get to work on my CD player.
So far I've had no failure with CD-R's from Sony, TDK etc... Which were the disks my CD player simply would NOT play.
i have entire 1993 CD-R spindle (Score:5, Interesting)
Were those disks verified? (Score:5, Interesting)
I've had CD-Rs and DVD-Rs that I burned over a decade ago still read fine. However, those disks were verified burns where I immmediately read back the data with Nero to make sure they were ok.
There was a time when I didn't do verified burns. Those disks have a ridiculously high failure rate, but I'm betting they were bad burns in the first place. With most media I get close to a 10% failure rate on verifying the burns.
And water is wet (Score:2, Interesting)
Re:Not sure that hard drives are any better... (Score:3, Interesting)
Though I'm not convinced many consumer hard drives have shelf lives on the same order as the optical media that some of us are backing up to.
Actually, kept in a cool dry place most hard drives will last pretty well. They only have durable SMT components on them these days. The only thing you've really got to worry too much about (Assuming you keep them away from moisture) is the bearing lube*. I suggest buying drives from different manufacturers if you're worried about that.
* I don't know if this has ever actually happened to a hard disk, but the lubricant used on the headlight switch of my 300ZX was corrosive after the passage of years, leading to a short and the failure of my battery.
Re:i have entire 1993 CD-R spindle (Score:2, Interesting)
I'm a little confused on the year. Does the collection start at '93 or '95?
Re:And water is wet (Score:3, Interesting)
My experiences with CD-Rs - some good, some not (Score:5, Interesting)
For the disks that I could not get 100% reads on from the Toshiba drive, I tried them in several other computers using a variety of programs. Mostly I was not able to get results as good as EAC on the Toshiba drive. I tried two Mac Mini's using Max and an old Mac G3 using cdparanoia from the command line, and got lots of failures. Then I tried Max on my MacBook and they all read perfectly. Go figure.
I theorize that one reason the disks had errors was that they were labeled using a Sharpie. According to the NIST report on CD-R failures (nvl.nist.gov/pub/nistpubs/jres/109/5/j95sla.pdf), this is a really, really bad idea. Since I read that report, I've been adamant about using only water-based markers on CDs and DVDs.
CD-Rs Design is Flawed. DVD-R More Reliable. (Score:5, Interesting)
CD-Rs design is very flawed in that the recording layer is near the surface as opposed to being well protected in the middle, as it is in DVD-Rs.
I've had numerous CD-Rs that were well cared for get flaky after a year or so; data is usually still there, but requires use of various recovery tools.
DVD-Rs have been very reliable in comparison - never had a problem.
With that said, what I do for archival data is use two different brands of DVD-R *plus*, when possible, save two, sometimes even three, duplicate copies of the data on the same DVD-R. That way I have two to as many as six copies of the data, often including dups on the same DVD-R allowing for faster, more convenient recovery.
Ron
I had a different problem (Score:3, Interesting)
I go and reinstall windows on my dad's machine. I use an nLited burnt CD I made(HP made CD) and it won't even boot. Tried a linux recovery CD(same maker of CD), would not boot. Somehow, out of the 6 tries I was able to get the XP install CD to boot. It did. Failed about halfway, asking for the file "ASMS", which didn't exist(but a folder did).
So, bad Cd? I fire up a virtual machine, and install XP in the machine and it works flawlessly.
I go back to my dad's machine & eventually try my legit store-bought XP install CD, and it continued to install. I burn a CD of my dad's backed up data(again, an HP cd), and it reads just fine on my machine I burned it from, won't read at all on my dad's system.
Wow, I'm lucky.
"Archiving" a single medium isn't necessary (Score:4, Interesting)
HD storage is incredibly cheap and like others have pointed out, we've only had 3 major interface changes in the past 20 years.
I can't read anything from my first personal 10 MB HD, either, but that never mattered. Each upgrade, transferring that to a new set of drives was trivial. I still have emails I wrote 10 years ago, not because I can read the drives. Those drives have little to no utility to me as a storage medium. I have that data because it was a 250MB HD and that takes up less space on my NAS than a single 1080p movie trailer.
In five year's time, I'm not going to be interested in reading the HDs I have now because they'll have long been transferred to the 50TB NAS type solution I'll have then.
Comment removed (Score:5, Interesting)
Re:i have entire 1993 CD-R spindle (Score:2, Interesting)
Re:Depends on the brand (Score:3, Interesting)
I have CD-R's from a variety of brands that have failed in the first few years. The discs from my burner back in '99 are dead, I tried those a year or so ago into the trash they went. Personally I'm not sure if it's a problem with the discs in some cases, or the newer drives not following the proper standards. I also have DVD-R's that no longer read, and DVD-RW's
In some cases, I find that the new multi-drives will fail to properly read burned CDRs(much like the days of yesteryear when burning was hitting it's hayday), but regular(if you can find them), CD drives will read them fine.
Physical damage trumps all other considerations (Score:3, Interesting)
But no one really made it clear how physically fragile the damn things were, especially in comparison to pressed silver CDs. I kept my backups in a booklet-style binder. Yes, I know that's considered less than ideal, but these discs weren't burned solely for archival purposes -- I needed to be able to page through them efficiently. Most of them were taken out and used every so often -- say, four times a year on average, sometimes more -- and never knowingly abused.
Over time, the foil on quite a few of them started to flake off. Unbranded Taiyo Yudens, which are so often acclaimed, seem to be the most vulnerable -- I've had quite a few that developed holes in the foil, especially near the edge. It's a shame, because the discs read beautifully otherwise, and seem to ace most media tests. But the foil seems all too easy to damage.
(I've also lost a handful of Mitsui Silvers that way, whereas Mitsui Golds seem to have a more robust armoring on top, as do some of the 2nd tier discs I've tried -- Sony, Maxell, TDK, Memorex. Meanwhile, I've seen no evident physical damage to my DVD-Rs so far; fingers crossed.)
Re:Buy Quality Blanks!!! (Score:5, Interesting)
The "codes" on a CD-R that indicate the manufactuer are pretty much meaningless. Why? Because they are often the code assigned to the manufacturer of the stamper.
Stampers are hard to make and require a cleanroom, lots of chemicals and skilled people. After you have a stamper, you put it into a machine and any idiot can turn out CD-Rs. So plenty of manufacturers with the cleanroom facilities and the knowledgeable staff sell stampers. So you have some place like Ritek that will sell anyone stampers. Now Wong's Cheaper Discs buys up some stampers from Ritek and starts turning out discs.
Since Wong's Cheaper Discs are a few cents less than anyone else's that week, Memorex and lots of other folks buy up discs from Wong's. Sadly for Ritek, all the discs from Wong's have the manufacturer code from Ritek. Now someone from Ritek might be able to tell you that these discs were not actually made by Ritek, but it is going to take someone familiar with their processes to tell you that. It is not obvious.
So the manufacturer codes on discs are pretty useless. About the only thing you can do is buy discs from reputable manufacturers where you actually know who the manufacturer is.
Re:i have entire 1993 CD-R spindle (Score:5, Interesting)
The 10% failure rate reported was from 1 person's experience copying old discs back to a hard drive. No mention was made of the CD hardware used or at what speed they were recorded at.
Use CD-RWs instead. (Score:3, Interesting)
Re:i have entire 1995 CD-R spindle (Score:3, Interesting)
Re:Buy Quality Blanks!!! (Score:4, Interesting)
I want to disagree with you, cdrguru, but with your low UID and telling username, I find myself unable to.
Instead, I'd like to ask you a question:
I had understood that, for the past many years, most CDs (whether recordable or not) were injection-molded, not stamped. Do you have any evidence or anecdotes to suggest that the primary manufacturing process for recordable media these days still involves stamping?
Re:Buy Quality Blanks!!! (Score:4, Interesting)
Yes there is not a 1:1 correspondence between the code and the actual manufacturer.
BUT for people who follow the industry the codes can still be used to identify the real manufacturer, and in many cases can be used to identify people who are forging manufacturer IDs. Lots of people like to put TY02 on discs that never saw any part of Japan.
And in any case they are FAR more meaningful than the label on the box.
Re:CD-Rs Design is Flawed. DVD-R More Reliable. (Score:3, Interesting)
As long as we're presenting anecdotal evidence....
A decade or so ago, I used to burn my disks on a Plextor PX-820. Every single disk that I've tried, no matter what the manufacture, has read just fine on modern systems.
Please allow me to suggest that your currently-unreadable burns were bad to begin with. Please further allow me to suggest that a bad burner back in the day is still a bad burner today, and that any media you have from Way Back When is sure to reflect this fact.
Re:According to... (Score:5, Interesting)
About 4 years later we lost a drive array and wanted to restore from the CD backup. I set one of my people to offloading the CDs to a new set of drives. Meanwhile I went to our offsite backup and copied the relevant data back to the server in a few hours. Days later my employee comes back to me and says that "most" of the CDs are coasters and the data is gone. It turns out that about 1/3rd of the CDrs either didn't burn properly in the first place, or had failed in the 2-6 years they were on a shelf.
The lesson was a simple one. The offsite backup server was faster, easier and more reliable than the CDRs. Of course, management blamed the (long since) fired employee that burned most of them. They also paid 5k$ for a brand new Mass burner / labeler, and used up nearly a week of production time getting it working and tested.
A year later the clients all moved to USB thumb drives and or FTP transfer for the data, making the fancy mass burner obsolete.
Archival hard drives? (Score:3, Interesting)
I've often wondered if there'd be a market for hard drives especially designed for long-term archiving.
They'd be slow-spinning, with slow transfer rates, and hold less data per square centimeter of disk surface, for the extra magnetic integrity. Some archivists wouldn't mind if they were very large, too, or even very heavy. They could be shelved in a "slow cloud" backup warehouse. They'd be "set and forget" - used once to record the data, then shelved and hopefully never used again, and only when a slow data restoration would be no hardship.
Surely there's a niche market for an odd device with specs that emphasize duration of storage, rather than the usual "faster, smaller" attributes. Until those long-awaited chalcedony drives arrive, it seems there's a niche opportunity here for a low-volume, high-margin manufacturer.
Hard drives have advantages over optical media (Score:3, Interesting)
Backups are not archives. Backups are a copy of working state, such that you can restore working state if it is lost or corrupted, partially or totally.
Optical media is poorly suited to backups, for a number of reasons. Optical media backups are:
In all those cases, hard drive backups are a win. External hard drives (I won't consider internal here, but the same generally applies) are easily automated, requiring no operator intervention. External hard drives can be copied to new hard drives easily - plug in the second drive, drag and drop all files, and walk away. Hard drive backups are easily searched (assuming good software, I'll just assume you have Time Machine or equivalent). Hard drive management interfaces can report disk failures or sector entropy as soon as it happens (and external enclosures offer RAID-1 at an affordable price point now).
If you lose your backup drive(s), it's not a big deal: get a new drive, do a backup straight away. You'll have lost your recent history, which means you may be out of luck if you accidentally deleted a file yesterday, but your current data's integrity is preserved.
Archiving is a different matter. If the goal is to have highly reliable archives, again, I think hard drives offer many advantages over optical media -- do the archival work on the working system, thus letting the entire archive be backed up. Storage space is going to be your limiting factor, but hard links or delta storage can help for regular archival intervals with small deltas (eg, your SCCM repository is an archive using delta storage, you back up the repository itself, not each revision). If the goal is to have many archives, with less emphasis on reliability, optical media is probably the winner: you don't need to verify the discs regularly since individual reliability is not a key metric, and you can churn out a lot of archival entries cheaply this way. If you have massive storage requirements and massive reliability requirements, you're not doing it on a home user budget, unfortunately.
I can talk about enterprise-class storage and backup solutions if you like, running into the hundreds of thousands in capex, millions in aggregate in opex, but it might interest you to know that despite all this money thrown around on backup systems, we still run cheap USB drives attached to laptops and desktops, because it gets a user back up and running in their original configuration in half a day if their system fails and needs replacing (and frankly, I don't want to waste our enterprise storage on terabytes of staff music and photo libraries :-)
re: recording speeds also probably matter (Score:5, Interesting)
Back in the earlier days of CDR, a "high speed recorder" was recording at a whopping 4x or so. As drive recording speeds increased, the CDRs rated for those higher speeds had to become more responsive to the laser hitting it for a shorter period of time. How do you accomplish that? One big way was spreading the dye out in a thinner layer. That's likely to have a negative effect on longevity.
Buy Quality Media (Score:4, Interesting)
is what it takes to get the maximum lifespan from your archives. This means not buying the cheapest shit you can for your important data. Instead the only one who meets the entire specification is Verbatim media. Sure it's not the cheapest when it comes to media but in the long run, it's certainly cheaper then buying whatever happens to be on sale at best buy and if your data is important, then spend the extra money for quality media, which is exactly what Verbatim is.
In my normal useage, I now only buy Verbatim for anything that I need to ensure is archived for any length of time. Otherwise for a quick and dirty backup, I'm now using an external drive then burned to Verbatim media for longterm storage. For those cheap and rapidly changing ISO images, the cheap disks are sufficient (things like FC/Ubunta/Kubunta and other Linux Distro's) In fact, I've found that buying Verbatim Rewritable media has become the cheapest solution for the many test images I burn due to the quality of the material. I'm still operating on my first batch of 10 Verbatim DVD/RW disks (now pushing 5 yrs) because they've lasted through so many rewrite cycles. I've also used cheap disks and the damn things have gone to crap in just a few months.
100% failure sounds right for Verbatim (Score:4, Interesting)
Re:Depends on the brand (Score:4, Interesting)
Long time storage is a problem (Score:3, Interesting)
That CDs/DVDs won't last forever was a given. That we relied on them is simply due to us considering the promised 10 years "long". Other media last longer. But is there something that will last forever?
Let's be honest here. Imagine our civilisation fails for some reason. And in a millenium or two, archeologists want to find out how we lived. What will they find? Well, of course they will find a lot of plastic bags and maybe a few cans, a couple glass bottles and some foundations of houses and churches. But anything we wrote? Any data we collected? Art? Anything at all that shows we were literate?
Aside of grave stones?
It's amazing that in almost 10 millenia of culture we didn't manage to invent anything but stone tablets to record information "forever". Nothing else will survive. Digital data fails before a century. Current paper won't survive for more than a few centuries, even if stored properly.
It's a curious mind experiment to ponder what would the average archeologist think of us if he finds some of our artifacts with no further data. Considering how most artefacts that make no immediate sense are classified as "religious" or "cultural", my guess is that we'll be considered a lot more religious than we really are, and that Pepsi is our god, and the Pepsi cultists were in heated battle with those that worship the Mountain Dew.
Re:According to... (Score:3, Interesting)
I had a strange experience the other week like this. I went back to some old CD-Rs, which would have ranged from about 7-10 years in age. Some were among the very first CDs I ever burned, on my old 2x drive, back in the days when the disks themselves cost £1.50 a pop here in the UK. The very oldest were actually fine. The slightly more recent ones (at the 7 year end of the range) were far more of a mixed bag. Around 1/3rd of them could be read only partially, or not at all. I'm pretty sure that the lower quality of these media (the newer CD-Rs would have only cost around 25% of the price of the older) was a big factor in that.
However, all was not lost. I have a very, very, old 2x CD-ROM drive that I keep lying around because it can read pretty much anything that isn't actually heavily and visibly scratched. So I plugged this in and, sure enough, it was (eventually, with a lot of grinding noises) able to get the data off the wonky CDs. I'm not quite sure why this should be; that a 15 year old CD Drive from the days when Rebel Assault and Mad Dog McRee were top of the line should be able to read disks that 3 modern drives (a Blu-Ray reader and two different DVD-RW drives) just gave up on, but I wasn't complaining.
Comment removed (Score:3, Interesting)
Where are the quality disks gone to ??? (Score:4, Interesting)
As DJ I used to store all my vinyl on CD as backup. I've once used my cd's for over a year in hard-dj-labor and most of them did survive although I might add:
Re:According to... (Score:3, Interesting)
CD rot is the result of bacteria getting inside the disc to eat the silver oxide or glue. And that's a result of the edge of the disc being damaged such that they can crawl inside. As long as the edge is remains undamaged/saled you'll be okay. Ditto if you keep your CDs in a dry place (i.e. not your wet basement) because bacteria don't like dry zones.
VHS tapes have a similar problem where exposure to humdity makes the magnetic media literally fall off. So you need to keep them someplace dry.
Re:According to... (Score:3, Interesting)
isn't that part of the problem with optical media? Every trip from storage to the reader is an opportunity for damage to occur. At least a hard drive's disk is kept safely in a metal box away from humans.
Sure, that is a problem but processes can be put in place to keep the risk of damage low, it isn't very difficult to handle optical media correctly and carefully. One solution would be to just use DVD-RAM discs which can be bought in protective catridges which prevent the disc surface from being touched and should prevent contamination/damage except brute force or U/V damage.
As I pointed out before the problem with a hard drive compared to optical media for long term archiving is a HD contains many parts that can fail since it contains all of the data reading components too. This means if you come back to the data archive in 20 years you run the risk of all the complicated internal parts having a failure and you also may not have a way to hook up a SATA drive at all anyway. With optical media all you have to fail is the polycarbonate and the materials storing the data on the disc.
So you see by using optical media for long term archival you just have to check the discs however many years you wish to make sure the data is still readable and you just have to make sure to keep a drive around that can read optical discs and as new I/O interfaces come about the manufacturers will convert the new optical drives to have the new I/O interfaces. After 25 years with a hard drive you would not only have to worry about the reading components in the drive still working correctly but you also would need to make sure you always have a way to connect whatever 25 year old interface is on the hard drive to a new computer. Of course you could just keep old components around but that just adds more cost and extra work compared to the optical media option.
For those concerned optical media is going anywhere anytime soon I don't think so, there are just too many situations it is the cheapest and easiest media to use (want to send grandma and your parents and your siblings who live 100's of miles away your gigabytes of vacation photos and videos then make a DVD you can easily and cheaply mail and can be viewed on a DVD player or computer, etc). Optical media is also the most abundant form of computer media in the world so there will be a demand for optical drives for a long time. Another thing is all optical drives are made to be backwards compatible with older types of media too which is a huge benefit.
Consider this, I could go get a copy of the first audio CD ever released (happens to be an "ABBA: The Visitors", I had to look it up) which was released 25 years ago and I could walk into Best Buy or any electronics store and play the CD back on most likely any computer in the store. What other 25 year old media could that be done with?