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Media Data Storage

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 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.

  • 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.

  • 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?)
  • by WiiVault ( 1039946 ) on Sunday July 19, 2009 @08:49PM (#28751585)
    How this god modded insightful is beyond me. CD-Rs, especially cheap ones are known to degrade. Heck 10% in 10 years is actually pretty darn good even with decent media. Arguing this isn't true is like saying magnetic media doesn't lose a charge. I'm shocked that all 400 discs worked when even some pre-fabed discs would have failed in that time. If this is for real you must be the luckiest person on the planet. Obviously discs were more likely better made back then too.
  • 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 Darkness404 ( 1287218 ) on Sunday July 19, 2009 @09:07PM (#28751695)
    Depends what you mean by "big enough", other than things that are redundantly backed up (my music and photos are on several MP3 players/iPods along with various flash drives, SD and other memory cards while other files are on one of my e-mail accounts) anything that really -has- to be backed up can fit easily in a CD-R. Sure, that won't get me every single movie I've ripped from DVD into a different format, sure its not going to get me all my applications settings, sure it probably wouldn't hold the 20 or so half-coded projects I've started but never finished. But all those are really pointless. I mean, sure, it would be a pain to re-rip all those DVDs, but over half of them I don't think I've ever really watched on my computer save for making sure the rip was done correctly, despite how I would like to finish my half-coded FPS written in python, I doubt I ever would. Other than a few financial documents, everything else is simply trivial.
  • Re:According to... (Score:3, Insightful)

    by RiotingPacifist ( 1228016 ) on Sunday July 19, 2009 @09:10PM (#28751711)

    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.

  • by Anonymous Coward on Sunday July 19, 2009 @09:42PM (#28751853)

    TFA mentions that there were various brands that exhibited failures, but this ultimately tells us nothing. CD-R branding is completely meaningless. What matters is the material/dye composition and the OEM, and the author did not control for this criteria.

    What you are most likely to find is that discs made from early materials are more prone to failure, as are discs from disreputable OEMs. These are the relevant facts for quality, and the lack of understanding about what determines the quality of a CD-R is what leads to popular myths, my favorite being the one about writing slowly to have a better or longer-lasting copy. If you have to do that, it means your burner and/or media is junk, and you are merely performing the voodoo that is necessary to make sub-specification parts work. A quality burner and media will write at 100% speed and it will be just as good as writing it at 2X or 4X or whatever other number people care to pull out of their collective ass.

    I have written hundreds of CD-Rs myself, and the only archival failures I've had have been due to cheap media -- and those tend to fail fairly quickly, it doesn't really take 9 or 10 years, and there's a pretty good chance that the bad discs in TFA died a long time ago, shortly after burn, but he's only gotten around to checking them now. Some of the cheap discs in my collection actually started turning color, as after a couple of years there was a visible gradient going from the outside towards the inside. If you can see the physical degradation of the disc then you know the data doesn't really have a chance.

    As always, backing up doesn't mean making one copy and then putting it somewhere forever until it's needed. Backing up means making copies on a periodic basis. If you wait 9 or 10 years between backups, you might as well have kept your data on the hard drive the whole time.

  • 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 Anonymous Coward on Sunday July 19, 2009 @10:36PM (#28752191)

    Arguing this isn't true is like saying magnetic media doesn't lose a charge.

    You mean, a non sequitor? Since when does magnetic media hold charge?

  • Re:According to... (Score:3, Insightful)

    by syousef ( 465911 ) on Monday July 20, 2009 @12:41AM (#28752969) Journal

    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 because most players read the discs. Other data simply doesn't. The only exception is a temporary low cost solution for mailing or passing a few GB to a friend. If you don't expect to get the media back it'd be too expensive just giving them USB thumb drives so CD/DVD fills this niche. Other than those two uses I can't think of a good use for DVD/CD. Certainly not archival storage.

  • 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:According to... (Score:3, Insightful)

    by bemymonkey ( 1244086 ) on Monday July 20, 2009 @05:25AM (#28754087)

    The thing is, it's a lot easier (and probably cheaper) to buy two 1.5TB SATA drives and just back up from one to the other every now and then, instead of burning 1500/4.7 discs once a month. I've moved to a completely hard-drive based backup solution, where I have every piece of important data on two separate hard drives. (Incremental) backups take 5 minutes instead of half a month, and all I need to store is two 3.5" hard drives... far better than hundreds of optical discs...

    As for optical media failures: I've had _a lot_. Sure, I never used archival quality media or a top-of-the-line burner, but I hardly think that most people who backed up their family photos on CDs or DVDs use archival media or top-of-the-line burners... Hard drive failures? Not so much. In ten years or so, one failure (so about one out of thirty), which is OK if you're aware of it and use some sort of backup scheme or RAID1 to protect against mechanical failure.

  • Re:According to... (Score:1, Insightful)

    by Anonymous Coward on Monday July 20, 2009 @09:15AM (#28755299)

    while CD-ROMs use pits that are physically pressed into the disc and will easily last your entire lifetime (unless you toss them around like frisbees)

    Except for the ones where the metal layer develops tiny holes right the way through (visible when held up to the light) - i.e. CD rot. These are typically nearly or entirely unreadable. Not very common (3 out of 400 in my collection) but it does happen, regardless of the storage conditions or use. So it is a good idea to back up pressed CDs now disk storage is cheap.

All laws are simulations of reality. -- John C. Lilly