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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?"
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Up To 10% of CD-Rs Fail Within a Few Years

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  • According to... (Score:5, Insightful)

    by NervousNerd ( 1190935 ) on Sunday July 19, 2009 @08:22PM (#28751435) Journal

    According to manufacturers, CD-Rs should last for decades.

    According to their marketing dept., rather.

    • by goombah99 ( 560566 ) on Sunday July 19, 2009 @08:34PM (#28751513)

      Well you of course have to use an error correcting code. people who don't do that then blame the manufacturer's got what they deserved. For example, personally I get 120 years out of my CDs by encoding 699Megabytes of errorcorretion. this leaves me with 1 byte of data. but it last 120 years.

      • Re: (Score:3, Insightful)

        What are you talking about? AFAICT (quick google and wikiread) the only type of error correction you get on CD-Rs is inherent in the format of the disk, so it doesn't cost you any storage space (for data anyway). If you start adding extra layers of ECC (e.g duplicate all files and keep a hash table)then your not dealing with anything CD specific anyway.

        • Re:According to... (Score:5, Interesting)

          by Jafafa Hots ( 580169 ) on Sunday July 19, 2009 @09:53PM (#28751929) Homepage Journal

          While the GP was just joking, you CAN burn stuff to media with extra error correction of a sort. Burn it as rar files, with a certain percentage of the space devoted to par files. Redundant blocks that way - so if, say, 5% of the files are unreadable, you can reconstruct them. I suppose you could do the same thing across a series of discs, to be able to replace a bad disc.

          • Re:According to... (Score:5, Informative)

            by hairyfeet ( 841228 ) <bassbeast1968 AT gmail DOT com> on Monday July 20, 2009 @12:07AM (#28752799) Journal

            You can not only do that to ensure data, you can also use one of several free CD/DVD checking utilities and simply burn a new copy if the disc starts to go. I use DiskCheck [] to check the CD/DVD, which is free, and if I get a bad one I use Elprime Media Recovery [] which is not to recover it. With this combo I have been able to save discs that looked like my boys had used them for hockey pucks.

            But I have several discs from the days of my $300 1x DVD burner, and several from the days of my 12x CD Burner, and they are still readable. I just run the oldest discs through DiskCheck once a year and if it reports any troubles I make a new copy and chunk the old one. But CDs are...what? Like $15 for a 100? And DVD is $20 for 100? So replacing the discs that start to go bad with age is no problem, and lets face it, when they are cranking out discs for that cheap bad batches are bound to slip through occasionally, and I have my old 8x DVD Burner installed in a 733MHz I use for Win9x so checking is simply a matter of feeding it while I switch back over with my KVM to check results. But with a simple yearly check you can get your data back by simply getting it off before the media degrades. And I have had a lot less problem with CD/DVDs that have been sitting in a dark cabinet for 5 years than I have with HDDs that have done the same. YMMV of course.

            • Re:According to... (Score:4, Insightful)

              by bemymonkey ( 1244086 ) on Monday July 20, 2009 @05:15AM (#28754041)

              So you run 1000+ CD & DVDs through a "checker" once a year just to see if they're still working? Or do you just not have a lot of stuff to back up? :)

              • Re: (Score:3, Interesting)

                by hairyfeet ( 841228 )

                I have found by sticking with Ridata, which seems to be the best of the "cheapo" media IMHO, I rarely have any troubles at all for those less than three years old, in fact I rarely have trouble with the Ridata DVDs at all since I stick them on 50 pack spindles in a cool dry cabinet.

                Anyway I have a 733MHz Compaq deskpro EN SFF that is one of about a dozen I got when the school upgraded their secretaries in 05. Since I use the SFF as a monitor riser it is sitting right in front of me at all times. To run a ch

    • Re:According to... (Score:5, Informative)

      by suso ( 153703 ) * on Sunday July 19, 2009 @08:36PM (#28751529) Homepage Journal
      Exactly, in my own experience, I started using CD-Rs in 1996. Back in 2007, I spent the time to copy all my old CD-ROMs of value to a hard drive for archival. I found that pretty much all of them were readable, even the 5 or 6 that were from '96. The only one I had problems with was a hybrid audio/data disc that I foolishly wrote in a proprietary format. But 80 or so of the discs that were spread across all the years worked ok. I was actually surprised because I expected some to be unreadable. I do think its great that they are trying to improve the longevity of the discs though, but they should find a solution that doesn't require a special drive.
      • Re:According to... (Score:5, Insightful)

        by w0mprat ( 1317953 ) on Sunday July 19, 2009 @09:57PM (#28751959)
        I reccently went back to CD-Rs from the 90s, and didn't really think much of it. I have a stack of about 25%-30% unreadable CD-Rs from less than 5 years old. Interestingly these are mixed brands, some of the buggered ones.

        I would suggest as the cost per unit fell through the floor, so did any regard for quality control as well as the consumers lack of motiviation to drive all the way back to the store and get a replacement.
        • by King_TJ ( 85913 ) on Sunday July 19, 2009 @11:44PM (#28752667) Journal

          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.

        • Re:According to... (Score:5, Informative)

          by hairyfeet ( 841228 ) <bassbeast1968 AT gmail DOT com> on Monday July 20, 2009 @12:41AM (#28752971) Journal

          Are they data or audio? Because if they are data you can use Elprime Media Recovery [] to get most of the data back. It is $39 but you can see with the demo if it is gonna work with your discs or not, and how much it will recover. I have used it to get a good 85-90% back off of discs that looked like they had been used as hockey pucks, as well as for a couple where the dye had started to go.

          So if you haven't tossed the discs you can probably get a good deal of your stuff back. And since you used buggered I assume you are British, which makes $39 USD...what? Like $2 in your currency? And while I can't say about CDs, as I haven't used them for anything but Linux liveCDs in ages, I can tell you there are a couple of DVD brands I would avoid like the clap. One is a bunch called Ilo, whose dye seems to go bad after about 9 months, and anything branded Staples. Do they have Staples in England? If so to quote the great Monty Python "RUN AWAY! RUN AWAY!" as I bought a couple of 50 packs there last Black Friday and a good 40% were coaster and the ones that burned correctly were in the garbage in less than 6 months due to bitrot. I have never seen a shittier brand in my life.

          I have found Ridata to be the best of the cheapos as far as CD/DVD is concerned. I rarely get more than 5% coasters and have had no trouble reading 5 year old DVDs from them. And at $20 USD for a 100 from Newegg you just can't beat the price. You can also keep an eye on as they often get Taiyo Yuden CDs there cheap. Oh, and OT, but if anybody needs a server cheap Surpluscomputers has dual Xeon 3GHz HPs for $129. They'll even sell you a 10 pack of IBM dual Xeon 2.4GHz 1u for $599. Great place for when you need some hardware for cheap.

        • Re:According to... (Score:4, Informative)

          by klui ( 457783 ) on Monday July 20, 2009 @01:40AM (#28753203)
          Just because they're name brands don't mean they're good. I would think the biggest would OEM from the cheapest source. I only buy Taiyo Yuden recordable media.
        • Re: (Score:3, Interesting)

          by RogueyWon ( 735973 ) *

          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 lo

      • Re:According to... (Score:5, Interesting)

        by KahabutDieDrake ( 1515139 ) on Sunday July 19, 2009 @11:02PM (#28752389)
        I used to work for a company that burned about 100 CDs a day. Half were kept as "backups" on site. The other half were shipped off to clients that were only going to use them once to transfer the days data to their server.

        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.
      • Re: (Score:3, Insightful)

        by syousef ( 465911 )

        Two observations:
        1) You've been lucky. Others have not faired as well (and some of those others have tried very hard to only buy quality media)

        2) CDs and even DVDs are too small.

        Who wants to copy 222 DVDs to fill up just one terabyte drive? Who's got the time to sit there shuffling disks? I store backups on external hard disks. They cost roughly double what you'd spend on quality media and while it takes hours to copy across a terabyte of data you don't have to babysit it.

        Video only still belongs on DVD bec

  • Depends on the brand (Score:5, Interesting)

    by Goldberg's Pants ( 139800 ) on Sunday July 19, 2009 @08:23PM (#28751441) Journal

    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.

    • by plover ( 150551 ) * on Sunday July 19, 2009 @09:46PM (#28751885) Homepage Journal

      By brand, you mean "manufacturer". Most big names, such as Sony, etc., don't make their own disks, but buy them from an external factory and place their own labels on them. The various manufacturers have different chemicals and dyes embedded in their discs, and its that chemical composition that determines the longevity.

      Usually the brand will buy discs exclusively from one factory, but some of the off-brands (such as house-branded Office Depot or no-name discs at Micro Center) could be sourced from anywhere, and their quality will vary widely.

    • Re: (Score:3, Interesting)

      by Mashiki ( 184564 )

      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

    • Re: (Score:3, Informative)

      by Hurricane78 ( 562437 )

      I recommend to always update your BIOS. From what I know, this gives the BIOS infos on how to read more recent discs (they are apparently not all equal, which makes sense).

      I have to see it help though. Some readers are just shit. (Like my Samsung for DVD-RAMs [firmware crashes. hard.])

  • by markringen ( 1501853 ) on Sunday July 19, 2009 @08:25PM (#28751451)
    i have entire 1995 to 1998 CD-R spindle's and all 400 of them still function just fine. i recently had to run trough all 400 of them, and had zero read errors. i guess my discs are possessed by some magical force, or this is just bogus.
    • Re: (Score:2, Interesting)

      by Tablizer ( 95088 )

      I'm a little confused on the year. Does the collection start at '93 or '95?

    • Re: (Score:2, Interesting)

      by djrobxx ( 1095215 )
      In 1993 blanks were about $40 a piece. Mighty expensive spindle you got there! My first audio CD-R made in 1995 still works, despite NOT being kept in ideal conditions and being pretty banged up.
  • by La Gris ( 531858 ) <(ten.eduarion) (ta) (sirg.ael)> on Sunday July 19, 2009 @08:28PM (#28751465) Homepage

    120yers, lets start with archive rated CD-R, and use a decent recorder with a tray. Then write according to the orange book specifications.

  • by msobkow ( 48369 ) on Sunday July 19, 2009 @08:29PM (#28751477) Homepage Journal

    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.

    • I would say if you are getting 10% failure rate when you verify you are either using really cheap media, have too little ram, or are using an external drive on a congested USB chain. Or maybe its your burner. I use a pretty standard drive, and medium quality (Memorex) media and I would say about 1%-2% of my burns fail to verify and an additional 1% or so fail to burn in the first place.
  • The summary seems to want to lead us to backing up on hard 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.

    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. Add to that the fact that hard drive interfaces do change fairly often (some of us still have systems in the transitional period between IDE and SATA), and you could have potentially more irritating problems if you were to back up to hard drives instead.

    I suspect for paranoid user it may be more cost effective to backup multiple times to CD-R rather than to a hard drive. And on top of that, if one CD of your backup set goes, you are only out 700 MB or so. If you have a series of backups on a single 100+ GB hard drive, and it fails, you may be out everything that was on that drive.

    • Re: (Score:3, Interesting)

      by drinkypoo ( 153816 )

      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

      • Re: (Score:3, Informative)

        by adolf ( 21054 )

        Fortunately, Nissan doesn't make hard drives(*).

        Of course, the grease in the bearings can dry out, but that really doesn't seem to be much of a problem: It's a silicone-based substance, and it's wrapped up pretty tightly away from the ambient environment. There just isn't much for it to do except sit around and be stable... Old drives used oilite (sintered bronze) ball bearings almost as a rule, while newer ones often use fluid dynamic bearings -- and in either case, that aspect is fairly stable.

        I've rec

    • by adolf ( 21054 ) <> on Sunday July 19, 2009 @08:47PM (#28751577) Journal

      "Fairly often"? On what timescale?

      In the consumer market: We had ATA for something like twenty years. And now we have SATA, with no replacement in sight.

      Before that, we (consumers) had MFM and RLL.

      And that, sir, is the complete history of PC hard drive interfaces.

      So, again: "Fairly often"?

      • In the consumer market: We had ATA for something like twenty years. And now we have SATA, with no replacement in sight.
        Before that, we (consumers) had MFM and RLL.

        Unless, of course, you were a Mac user. In which case you used SCSI for some time, before switching to IDE.

        And now most people are using SATA.

        Assuming, of course, that they are using a system that is only a few years old (or less). There are still plenty of systems in operation using IDE, as much as the drive manufacturers might not want to believe it.

        And of course, if you are backing up your files, then the duration for which you want to keep those files may vary. If someone wants to keep those ol

    • by Darkness404 ( 1287218 ) on Sunday July 19, 2009 @08:48PM (#28751581)
      It depends though, you can get SATA to USB docks for next to nothing and I don't see USB going out anytime soon, if anything the external HD will crash (or end up being terribly obsolete) before USB gets replaced with anything more than the next version of USB. I mean, with USB appearing on -everything- from cell phones, to game consoles, to cigarette port chargers and more, I just can't see it being replaced especially when some legacy ports are still on many computers (does anyone really connect their printer via parallel port anymore? and aside from legacy systems and embedded systems does anyone still use the serial port?)
      • I don't see USB going out anytime soon

        It wasn't that long ago we thought the same about the parallel port. I suspect I'm not the only person here who used a Zip drive through a parallel port interface "back in the day".

        does anyone really connect their printer via parallel port anymore?

        Well, junior, we used to connect more than just that through parallel. And not everyone likes to replace printers that still work; I have a parallel port laserjet that I still use from time to time because it is the cheapest way to print available to me at home.

    • by Weedhopper ( 168515 ) on Sunday July 19, 2009 @09:52PM (#28751919)

      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.

      • 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.

        And what if your NAS fails? Or is it fully redundant RAID-1? Or are you backing up to something else?

    • 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:

      1. ... a manual process involving physical media swapping, and thus requires high discipline to perform regularly;
      2. ... time consuming to migrate to new media, whether due to an interface change or to outpace entropy;
      3. ... time consuming to search, as you need to m
  • Old news (Score:4, Informative)

    by Drinking Bleach ( 975757 ) on Sunday July 19, 2009 @08:40PM (#28751543)
    CD-Rs, DVD-Rs, whatever, the burning process might have some anomalies not picked up immediate, the media is low quality, or (more likely) the laws of physics erode away at the data. This is not secret or new information, it's been known for a long time. Granted that most of my collection now has a high amount of data loss (and I've encountered several instances with corrupt data... not all that I really care about, although sometimes I do work at recovering any damage I might find, especially if it's possible to verify "corrected" files with known good checksums, or infer the original contents (with, for example, text files)), since about 2005 or 2006, I've always made recovery ( discs to maintain the maximal possibility of recovering data in the future. It effectively halves the capacity of my spindles (eg, in a 100 stack, I might use 50~60 for actual files and the rest for recovery files), but it's worth it; I've already encountered quite a few cases of bad media from after the time I started making parity files, and boy am I glad for it!
  • And water is wet (Score:2, Interesting)

    by EsJay ( 879629 )
    Digital media are not permanent and who cares. Make more digital copies. Repeat.
    • Re: (Score:3, Interesting)

      by ickleberry ( 864871 )
      Make more copies onto something more reliable or else you'll never get around to doing anything other than making copies
      • I buy a new "main" computer about once every 5 years, and replace a HD about once every 8 years (stick the old HD in the new computer and copy data over, repeat) unless both HDs fail really quickly, I only would need to resort to optical backups for any newer data which is a lot smaller than all my archived files. Plus, none of it is really -that- important (or isn't redundantly backed up on some old laptop/netbook/flash drive/e-mail accounts) that if all the newer stuff failed I wouldn't be losing all that
  • dvdisaster anyone? (Score:5, Informative)

    by MoFoQ ( 584566 ) on Sunday July 19, 2009 @08:42PM (#28751555)

    dvdisaster [] is what I use now...both on CDs and DVDs (it also supports dual-layer)

    think of it as a way to embed par2 (parity) onto a disc (it requires an ISO image that you create in your favorite authoring software, then after it's done embedding the parity in it, you can burn it)

    alternately, you can create a separate recovery data which you can store on backup tapes or hard drives or on another disc, etc.

    • Here are suggestions I follow. I heard this from a professional archivist who works for Federal courts.
      1. Always burn at slower speeds than maximum speed of the burner
      2. Don't fill completely to capacity. The media burns from the inside-out. Because it turns at constant rate, the data on the outside tracks may be more affected by small degradation of the encoded pits
    • think of it as a way to embed par2 (parity) onto a disc

      I'm not trying to be smart, but why not just burn disks full of par2 files? I'm asking because that is exactly what I currently do. It has the added advantage of letting you span disks with data that is larger than the size of one disk. Just make a disk image of whatever size, and then act like you're going to post it on usenet except burn to disk instead.

  • Ever since the good ole days of CD-R I used to burn them to find they didn't really work after a couple of months. I actually think all optical media is like that - you burn it, should last for a few weeks after that it's hit or miss. Pressed CD's seem to last forever but not anything you burn yourself

    After all it seems the only reliable storage is flash memory, preferably SLC
  • by the eric conspiracy ( 20178 ) on Sunday July 19, 2009 @08:51PM (#28751593)

    "Studies" like this are useless if they don't include information from the codes off the CD's (not the label on the box!) as to who the manufacturer is.

    Get the Taiyo Yuden and MAM-A Gold blanks and you won't have issues like this.

    Also please read the Wikipedia article on CD-ROMs, and expecially the references. You WILL end up with better burns if you do.

    • by analogue_guy ( 892989 ) <> on Sunday July 19, 2009 @08:59PM (#28751655)

      Mam-a is not what it used to be.

      Buy Taiyo Yuden or Falcon.

    • by cdrguru ( 88047 ) on Sunday July 19, 2009 @10:15PM (#28752069) Homepage

      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.

      • by adolf ( 21054 ) <> on Sunday July 19, 2009 @10:45PM (#28752287) Journal

        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?

      • by the eric conspiracy ( 20178 ) on Sunday July 19, 2009 @10:48PM (#28752301)

        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.

  • by PatMcGee ( 710105 ) on Sunday July 19, 2009 @09:16PM (#28751733)
    I recently tried reading a bunch of audio CD-Rs burned between 2003 to 2007. I used Exact Audio Copy on a Toshiba drive. I was able to get error-free reads from about half the disks recorded in 2003; about 3/4 of the ones from 2004, and from all the ones recorded after that. On the early ones that worked, sometimes EAC took a couple of hours to do the reads, which means it was doing a lot of retries. On the later ones, the transfers were mostly just a few minutes. On the ones that reported less than 100%, sometimes EAC spent 50-60 hours trying.

    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 (, 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.
  • So just what are the "ideal conditions" for storage of optical disks?

    And, while I'm asking questions, has anyone ever experimented with submerging disks in (water | mineral oil | etc) to see if that would reduce long-term degradation? If we're talking 5 years or more I wouldn't mind drying/cleaning them to get my data.
    • Re: (Score:2, Informative)

      by Anonymous Coward

      cool dry place w/ no sunlight / UV. get a large CD storage folder (they usually have em for holding 500 or so disks and leave it in a drawer.

      see here :

      520 Disc Capacity CD DVD Wallet Case offers Koskin/Black Leather-Like Quality CD/DVD Portfolio, Organizer, Case, Wallet, Holder with Sturdy Handle, Comfort Shoulder Strap, Removable/Refillable Binder Style Inserts with Easy On/Off Switch. Perfect for professiona

  • by Ron Bennett ( 14590 ) on Sunday July 19, 2009 @09:20PM (#28751745) Homepage

    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.


    • Re: (Score:3, Interesting)

      by adolf ( 21054 )

      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.

  • by Tumbleweed ( 3706 ) * on Sunday July 19, 2009 @09:22PM (#28751747) the venerable 5.25" floppy disk, circa pre-1985. My Apple // disks from that time are still readable. It takes rather a long time to back up my 1TB WD "Green" HD onto the Apple //GS I have networked to my main machine, but hey, backups are important! :)

    • Punched cards or punched tape using something stronger than ordinary paper is very good for long-term storage. In ideal conditions it can last millennia.

      If that's not good enough, non-organic inks on cave walls and cut indentations in stone can last even longer if protected.

      OT: "It's been 4 minutes since you last successfully posted a comment" WTF? When did /. start limiting you to 1 comment every 4 minutes?

  • by analogue_guy ( 892989 ) <> on Sunday July 19, 2009 @09:26PM (#28751763)

    I burn thousands of CDs and DVDs per week and here are some tips

      - use pro grade media from Taiyo Yuden (Made in Japan) or Falcon (Made in UAE). Verbatim still makes some good media but you have to know what to look for (Datalife Plus) because they also buy cheap media and rebrand it.
      - burn cd-r at 16 or 24x. 32x is ok for short-term use. Even the best discs will fail if you burn at maximum speed.
      - burn dvd-r at 8x
      - if you must burn dvd-r at 16x, test your quality regularly for signs of failure.

    how to test the quality:

      - Plextor made good drives bundled with Plextools testing software but they are no longer making their own drives. For a replacement to Plextools, see Opti Drive Control at

    • Yep, slower burn speed can make a difference. One of those details few people are aware of.

      For DVD-Rs, I limit burning to 4X. Probably overly conservative; 8X, as you suggest, is likely fine too.


  • I have had CD-Rs fail within weeks after perfect verifies. You should expect a lot less than the given times in "normal conditions".

  • 4 CD, Raid 5. (Score:5, Informative)

    by evilviper ( 135110 ) on Sunday July 19, 2009 @09:43PM (#28751857) Journal

    I used-to make 2 CDs of every ISO, until I figured out how best to utilize PAR2.

    PAR2 calculates parity information on a set of files, and writes out a file which can be used in the event that any of the files is damaged. This is quite similar to RAID-5, but PAR2 is more robust, and works on any files, not just equally sized hard drives.

    Though it's no help on DVDs, CDs work GREAT with PAR2, because of their two different methods of recording. Mode 1, as all regular files are stored, reduces the amount of space available by about 12.5%, using that space for additional error correction data. Audio CDs, and Video CDs, where a single bit error isn't nearly as critical, are recorded in Mode 2, with substantially reduced error correction, but about 100MBs more usable space available.

    PAR2 is similarly resilient to errors, so it can safely be used with Mode 2. This allows much more space for the parity information, and the opportunity to be safe against, and correct, respectively more damage to a disk.

    Specifically, I recomend a 4-disk parity set. You fill 3 CDs full of data, and tell PAR2 to calculate 37% recovery data on those files. The first 33.334% allows you to RECOVER THE DATA FROM ONE COMPLETELY LOST CD, no matter which of the 3 it is. That still leaves you with a margin of 3.667%, so those two CDs you DO have, can have a few bad sectors as well, and all the data from the lost CD, as well as undamaged versions of the files on the two lightly damaged CDs can be recovered. Alternatively, if you DON'T lose an entire CD, all three (4 actually) CDs can have numerous bad sectors, in any distribution, up to a total of 37% of all the discs, and pristine data can still be recovered.

    The method to do all this is quite simple. Just run the par2create command, telling it to create 37% recovery information. Then take the resulting BASENAME.Par2+??????? file, and create a CUE file, describing a CD with a single track across the whole CD, with the PAR2 file as the supposed audio data. eg.:

    FILE "par2.bin" BINARY
        TRACK 01 MODE2/2352
            FLAGS DCP
            INDEX 01 00:00:00
        TRACK 02 MODE2/2352
            FLAGS DCP
            INDEX 00 00:04:00
            INDEX 01 00:06:00

    Now, any CD recording software that understands CUE files will happily record this to disc. On Unix systems, you can choose cdrecord, or cdrdao.

    Now, like regular audio CDs and Video CDs, you can't just use or copy this data off the disc like a normal file on a CD. There are programs for converting VCDs into regular files, something like dat2mpeg, but I prefer a more generalized tool that can do the job:

        mplayer vcd://2 -dumpstream -dumpfile par2.bin

    You'll note that checksums of the file and the data on disk don't quite match... This is because, in mode2, data MUST be padded to the block size. PAR2 files are fine with it, and the padding is silently discarded.

    Something like DD_RESCUE to copy the (normal) files off the other CDs, in the event of damage, is probably necessary as well. Then, once you've got 3CDs worth of data (eg. 700MB CDs x 3 = 2100MBytes) you can run par2recover and all with be repaired, like magic.

    The only footnote being that calculating the parity information isn't fast, so this method is probably slower than just recording 2 copies of every CD. Also, if you lose more than 37% of the data across all the discs, the error-free originals can't be recovered. However, I consider it more reliable than duplicate discs, if only because the odds of an error on the same sector of two discs (or one disc lost, and the backup with a few errors), seems more likely than 37% of the discs being damaged beyond hope. And as an added bonus, you save 1/3rd on your CD-R purchases.

    • Re: (Score:3, Informative)

      by rdebath ( 884132 )

      Erm, that isn't Mode 2 records, that's audio data padded to 2352 byte blocks.

      Mode 2 sectors have a sync header plus a (minutes/seconds/sector No/Mode No) for each block and have 2336 bytes for each block. White book (video CD) sectors have an additional XA header and a 4 byte checksum with a final data rate of 2324 bytes per sector (Mode 2/Form 2 sectors).

  • by British ( 51765 ) <> on Sunday July 19, 2009 @09:46PM (#28751871) Homepage Journal

    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.

  • by silverspell ( 1556765 ) on Sunday July 19, 2009 @10:09PM (#28752035)
    I'm the kind of person who usually does a fair amount of research before he leaps, and so when I first started burning CD-Rs, I did everything more or less by the book. I used quality media (Mitsui and Taiyo Yuden), quality burners (Plextor), always verified my burns, and never used any crazy high speeds. My CD-Rs have held up well in many aspects, and I've only had a few physically intact discs that went bad for no apparent reason (most of which are from what may have been a problem batch of Mitsui Silvers, burned around 2000/2001).

    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.)
  • Use CD-RWs instead. (Score:3, Interesting)

    by w0mprat ( 1317953 ) on Sunday July 19, 2009 @10:35PM (#28752181)
    I found that burning CD-RWs twice (quick delete and then burn again identically with bit for bit) all but wiped out problems I'd had with rewritables.
  • by Hurricane78 ( 562437 ) <deleted@slashdot ... minus physicist> on Sunday July 19, 2009 @10:36PM (#28752185)

    (Throw a coin. If it's heads, read the P.S. first. Lucky you.)

    I remember a large-scale test with pretty much all CD-Rs and CD-RWs on the market back in (around) 2000 (I think).
    They used a climate chamber with all the effects of nature, amplified so much, that they could simulate 10 years of normal daylight, humidity, etc.
    The blue and green materials died first. (I think blue was much worse than green, but only for some models.) After an average of 3-4 years! The original golden material survived better, but not much.
    Only CD-RWs could even come close to 20 years, because they had to be manufactured better, and use other materials.

    I also remember that our very first CD-Rs, burned on a huge rented SCSI burner, at 13 DM a piece, were unreadable right when we took them out of the archive one year later. Which was still better than those 50% who never survived the first burning at all.

    Everyone around me always tells me that his old CD-Rs still work, and things like that. And they do not take me seriously when I tell them of the low life-span.
    But usually, they do not even take them out to try them. And if they do, they look at the directory index, and think that means that all data is OK. And even than sometimes fails.
    Also, they rarely can find CD-Rs, old enough to prove me right on the spot.

    But if you take those discs, transfer everything and all its data to the hard disk, and then look at what you get, usually what you're left with, looks like a shattered mirror or the output of a random number generator.

    P.S.: Sorry, just watched the Watchmen again (is that a pun?), and inadvertently wrote the whole comment in Rohrschach's journal voice.

  • by Darth Cider ( 320236 ) on Sunday July 19, 2009 @11:19PM (#28752517)

    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.

  • Buy Quality Media (Score:4, Interesting)

    by fast turtle ( 1118037 ) on Monday July 20, 2009 @12:55AM (#28753037) Journal

    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.

  • by RubberDogBone ( 851604 ) on Monday July 20, 2009 @01:56AM (#28753271)
    Back in 1994 or 1995, a whole bunch of us got into the PlayStation mod chip scene which naturally included a need to make burned game copies. This was right at the advent of home CD burning and burner drives were hundreds of dollars and ran at 1x or maybe 2x and were usually SCSI. It was FAR from the drop-and-go way we do disc burning now. Aside from getting it to work at all, another major issue we had was finding affordable blank media. $5-10 a disc was not uncommon, and failed burns were also not uncommon: these were the days of 1mb buffers and Windows 95 and klunky software that barely worked. We didn't have Nero or anything like drives with underrun protection. You could coaster a ton of media easy because the wind was blowing the wrong way, it seemed. So we were always looking for a way to get media cheap. Sam's Club came to the rescue with 10-packs of Verbatim CD-Rs for $10. A buck a disk. These days, that's a ripoff. In THOSE days, however, this was practically a steal. And the discs mostly burned fine and the PSX liked them. A perfect match. All the PSX game copy people jumped into Verbatim. I remember one friend who had 5 100-disc binders of copies and those were just the ones he kept. Another guy had bookcases full of discs in jewel boxes. Almost all Verbatim. Dozens of us locally went for that brand like crazy. We thought we had it made. This went on for a year or so before the problems started. Also, we ran out of good PSX games to trade at the same time. But we still had older good games. But problems happened. Previously known-good discs started going bad. Visually, we saw pits and spots appearing that looked kinda like craters or maybe mold. Sometimes spots, sometimes half a disc at a time. The problem was flaws in the dyes. Other discs delaminated -the cyan data layer actually flaked off the polycarbonate. Mostly we saw the rot and it hit discs stored in binders, in the original jewel boxes or not ever burned. It didn't matter how the discs were stored. It didn't matter how they were recorded or if they were ever played or how long they were played. Eventually nearly 90% of the Verbatim discs failed. The other 10% escaped only because we quit looking out of disgust. In short, several thousand game copies got wiped out by this failing media. Now there's the moral argument that what we were doing was wrong and we got punished in a way and that could be kinda acceptable if it was only game copies that died. But we also lost other fully legitimate burns. The product made no distinction. The product was crap. Why, who knows. I do know I won't ever use Verbatim for anything at this point. There's no trust or faith. I have used other brands of media all along and most of those from the same era are still good to go. TDK, 3M, Memorex, Sony, even some CompUSA-branded media still works fine. Cheap computer flea market media sucked too. Go figure. Mostly, bad media was rare unless you hit a product that was just inherently worse than another. Lessons were learned from this: don't trust media for permanent storage. A CD-R that dies is 640 or 700MB down the drain. Stings but you go on. A failed DVD is 4.5GB in the trash. Ouch. That hurts a lot more. Worse for DVD DL. That brings us to BluRay. 50GB a disc? I am not trusting THAT ever. And the one beyond BD that offers 500GB? No freaking way. ONE dead disc should not wipe out 50 or 500GB of data. Disc burning is not stable and secure and reliable enough to trust at that level and we as users and consumers should refuse to accept it. What else can we do? I don't know. But clearly burned media is not the answer.
  • by Opportunist ( 166417 ) on Monday July 20, 2009 @03:45AM (#28753697)

    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.

  • by freaker_TuC ( 7632 ) on Monday July 20, 2009 @07:10AM (#28754567) Homepage Journal

    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:

    • In Belgium we got the CD tax, preventing "good" cd's from being imported to Belgium; yup; we officially only got crap!
    • The recording industry sure likes this degration in material, preventing "good" long term copies being made of their products.
    • I've noticed a few differences the last years; most specifically: in quality!
      • BASF Ceram Guards; used to be the best with ceramic protection and perfect dye: production stopped. No degration at all.
      • Hi-Space Carbon Sound; black PS2 compatible cd's, work perfect and scratch free: not available anymore. No degration at all.
      • Verbatim CD-2 52x; They are good, just don't use them too often; very fingerprint sensitive! Degrades after a short time!
      • Maxell CD-R80XL colour; These seem to be scratch friendly, quite good but degrades after some time...
      • Verbatim Super AZO Crystal DL+; These fail more than ever! I do not know why they sell these!
      • MMore CD-R80; As long they are stored well, they will store data for longer times, not expensive either!
      • Sony CD-R Supremas; those cd's fail by the dozen; I'll be glad I will be through this stock.
    • These cd's get used on Plextor, Sony and Masterlink ML-9600 cd writers.
  • by JobyOne ( 1578377 ) on Monday July 20, 2009 @10:08AM (#28755803) Homepage Journal
    I can say that CD-Rs are pretty unreliable past about 5 years. I recently tried to open some old graphics files from our CD-R archives at work, and it didn't go so well.

    Everything I was trying to open recently was about 7 years old, and about half the discs wouldn't even read, or would throw errors when I tried to actually copy anything off them.

    It also opened up the issue of file formats...what the hell am I going to do with an Aldus Pagemaker file from 2001? Nothing in Adobe CS3 had any idea what to do with it. I think that's what that extension was, anyway. Archiving photos and videos is pretty safe as far as file formats go. A BMP is crappy and gigantic next to a TIFF or PNG, but you can still open it.

    Proprietary layout formats though...they get old faster than cheese in a hot car.

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