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CD-R Lifespan - Is It The Label?
sysadmn writes "Slashdot has discussed archival lifespan of CD-R media before. Fred Langa revisits the issue with a new twist: Are glue-on labels causing premature failure? Much more common than rain forest fungus! From Fred's informative LangaList newsletter."
A co-worker turned me on to Fred's column a couple of days ago, and I've been running a few tests that may or may not have a bearing on reality...
The cheap-ass CompUSSR CD-R with and without their corporate logo were the main object of testing.
In a nutshell, the pre-printed logo CD-R survived the label removal much better than the generic no-name blank did, though you _could_ screw up the printed one just as badly with a little effort.
We're going to get everyone in the office to offer up a sacrificial CD-R of choice to conduct more tests, and I will also introduce my co-workers to the Round Table Rate-A-Record system with the office microwave...
Then we'll see what happens to DVD-R/+R...
"Eustace? Eustace? Are you there? Are you there?" = John Leeming
Of the CDs I own, the ones that've gone bad have suffered damage to the top foil part. It either rubs off, or partially becomes dislodged from the bottom part. All the review sites seem to think the dye is the weak link in the chain, but in my experience a crapy foil will go long before the dye.
AccountKiller
Kodak used to subject their CDs to "torture tests" to see how they'd stand up. Their "Gold Ultima" CDs were reported to have a 100-year archival life. Now, they're saying the same thing about the Ultima brand (now that the Gold brand is discontinued). Study results are here.
:-)
All I can say is that Kodak seems to have done a lot worse to their CDs than your friend did with just his tongue.
D.
I used to buy cheap bulk no-name CDs. However, about 1 year later, the aluminum coating was flaky and fell out of the CD... So, when you can see the light through the hole from the fell-out coating... So, the CD breaks.
In this case, coating it would have helped. I dunno whether it would end up the same way as stated in the article, though.
But, if you can spend more money on CD-Rs, you'd be better up with branded CD-Rs and apply no labels.
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Error 500: Internal sig error
here is an easy solution that has worked for me for years. 1. get a perm. marker 2. label your cd-r "applications cd1" or "music cd1" 3. make a text file(html format works the best) list contents of each cd-r 4. done simple as that no wasted time trying to make labels.
All media degrades. The trick is to use redundant data, and re-copy it before the media is expected to fail.
Is there a way to detect when a CD is about to fail? The CD drive will auto-correct minor errors without informing the PC - so by the time a drive returns an error code, at least one block of data is lost (if you're lucky, you can copy everything else off the CD).
I'm aware of commercial testing hardware that can report statistics like the Bit Error Rate (BER), Block Error Rate (BLER), etc. But is there any way to do this cheaply, possibly using software?
I have noticed that on some of my CDR's, burning slower results in a different color than a faster burn. I guess the dye is being changed more when it is slower. So now, for CD's that I want to keep for a few years, I write them at 4x even though I have a 48x burner. As for the labels, I don't use them.
We need to worry. REALLY. I am burning a cd right now. The data is music. Music from about 25 years ago that was on a reel to reel (older tape analogue) that had to be baked (put in an oven to recover the lost footage more here: http://www.soundsaver.com/squealingtape.htm)
If I am burning this to CD and then the CD becomes faulty, which is likely from my experience, the CD becomes useless, there is no turning back. This has happened to me, a skip becomes more and more of a skip until unplayable.
CD's are not a good way to archive anything.
Given the state of DVD-Rs, backing up CDs to DVDs is foolish. Unless you have performed extensive compatibility tests with drive and media, you should expect your DVD-Rs to have significant BLERs, in some cases higher than the maximum spec, and that is right after you burn them, not a few years down the road. CD-Rs are still cheaper per MB than DVD-Rs, so if you already have your data in CD-sized chunks, back them up to CD, not DVD.
Memorex is consistently one of the worst CD and DVD manufacturers around. They usually have 1-2 bad discs in a 10pack. One 10pack I bought actually had 6 bad cd's. I can't remember the link to a good CD evaluation site, but here's one for DVD's:
http://www.dvdrhelp.com/dvdmedia
I had a similar experience (or so I thought at the time). About 50% of a spindle of cheap 10x CD-RW's simply failed even after repeated attempts to blank and reburn them. Fortunately, I threw all the CD-RW's that failed into my coaster pile rather than the trash, since about a year later after I had replaced my CD burner I discovered that every single one of them worked fine.
The failing burner was a Yamaha SCSI unit that I paid about $200 for four years ago; it was (and probably still would be) quite reliable with other media, but it was only a 24x8x8x unit, which is why I replaced it. Its replacement, a Sony 48x24x48x IDE unit (rumored to be a rebadged Liteon), cost $50 on sale. It, too, seems to work with everything I throw at it -- including those CD-RW's the Yamaha couldn't deal with.
I suspect that drive/media incompatibility is more common than most people think. Some reports of failing media may be due to media that was marginally recorded to begin with due to such incompatibility.
The first time I listened to it (for about 18 months) there was a bit of crackle that coincided with the baseline in all the tracks on the CD. The second time I listened to it, just a couple of hours later, the crackle was throughout the CD and very strong. It turned from a minor annoyance to completely unlistenable. I guess the power of the laser in my stereo was enough to destroy the data still further.
By going through a fair few of my CDs I found that it was only one brand (Princo) that was affected. CD-R's of other brands that were burnt earlier than the Princo ones still played fine. I've since gone through and re-burnt all the Princo CD's that had something important on them.
The CD's were Princo CDR-80's from several different batches. (I bought them a few times because they seemed good at the time.) Has anyone else had problems with Princo CD-R's or any other brands?
It's odd that you had problems with sony. Recently, my roommate moved out. We had 300 cd-r's that contained divx movies that were pretty much community property. I found a deal on 2 160 gig hard drives on pricewatch, so I bought the hard drives and copied all the cd's to harddrive (yes it took forever). It was an interesting experiment though because we have all major brand cd-r's in the collection. About 20 or so of the disks are dead after maybe 1.5 - 2 years. The sony disks faired better than any other brand we used.
We didn't use cheap bulk cd-r's because I know from experience they flake fast. The real interesting thing i noticed was that PNY didn't fair as well as I had expected over time. As far as I could tell, PNY works best in standalone CD players as far as being able to read, and always seemed to last awhile (at least long enough that I got tired of the CD and gave it away).
These are just my observations. BTW, half of these cdr's were burned on a plextor 8x4x2 and half on a sony dru-500a.
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Squirrel
I have a hard time believing this. I've had some CDR archived materials for 5 or more years that read fine. I think the bigger problem is clueless users (like I used to be) who mistakenly burned CDR media at a speed too high for what the media is rated for. Those discs seem to run fine at first, but then die later. I've lost several gigs due to this problem just because I know how I used to burn CD's.
After doing a stint as a printer rep I learned that the main reason that bulk CD printing is done by a silkscreen-type method is (apart from cost) is that mechanically applied CD labels have a tendancy to throw off the balance of the CD itself as it rotates.
Granted, (again from many hours with our tech staff) this is a much rarer problem these days as the drives have developed a higher error tolerance to rotational flutter. Just something to keep in mind when evaluating the failure tests.
the only CDs I have that have lasted more than 19 months or so are my Kodak Golds, the oldest of which were burned sometime in 1995. In particular, I've found any CDs that use a blue dye to be the most fragile/short-lived.
I have some 650MB TDKs (blue) I burned 5 years ago that are still readable now. Just another data point . . .
And to correct my first post, it's glue, not clue. :)
I've been using one of those label makers for years...you know the ones that print on a piece of tape. Not one problem yet, I use a clear tape with black print, shows up well and is very readable, haven't seen one of them fail due to fading or lifting.
Then again I take care of my toys and don't leave them laying around where they can get scratched or baked in the Sun.
Beats writing on them with sloppy handwritting and a sharpie IMHO.
Look for a tool called CDCheck CDCheck. Downside is that you have to manually manage the .CRC files. There's also a sourceforge projected calld CFV which is a command line tool.
Or, if you're burning a new CD, set aside 10-25% of the space for parity data using QuickPar. That way, even if a portion of the disk becomes unusable before you have time to copy it to a new disc, you have good odds of getting all of the data back off of the CD.
Wolde you bothe eate your cake, and have your cake?
Look into some sort of parity software to protect your files on the CD/DVD. They add extra files (usually 5-25% more space) that allow you to recover files that have been corrupted by the media degrading. I also create parity files for files on my hard drive (in my archive tree) because there are command line tools that will walk the directory tree and verify that all files are still clean. Take a look at QuickPar for a parity tool. For a DVD, I'd recommend setting the percentage to 10-15% (will eat up around 15-20% of the DVD with parity data).
Now for professional data, I'd recommend a few methods. First, hook up a 250Gb USB 2.0 drive and get software like rsync or SecondCopy 2000 to mirror files off to that drive daily. (SecondCopy has the ability to move deleted files to a seperate folder on the external drive, plus keep multiple revisions of changed files.) An advanced option is to get (3) drives, swap them weekly or bi-weekly, keeping the latest backup at an off-site location. Might want to get one of those custom foam carrying cases to put the USB drive in. I'd recommend getting the USB drives that have built-in power supplies (take standard computer cords) which gives you one less thing to lose or carry around. Peer II sells a nice, compact USB 2.0 enclosure (CA-405U2) that supports large format drives (if you get the latest models).
Consider a tape backup that holds 50Gb native. Tapes are nice because they're small/portable. Downside is that tapes are expensive and backup software on Windows machines is usually proprietary.
You'll still want to do the DVD-R method as well, which is a very good way to take snapshots of projects. Protect it with parity files, but don't depend on it as your only backup method.
Wolde you bothe eate your cake, and have your cake?
Check out the freeware win32 tool Nero CDSpeed which has many excellent functions for measuring the quality of optical discs (CD, CD-R, CD-Rw, DVD, etc) and tools for verifying the integrity of stored data. Its scandisc function test the drive's ability to read each file at the filesystem level and read each sector at the physical level, telling you which sectors are good, which are failing and which are dead.
An interesting side effect of using this tool is that I've noticed that the manufacture of pressed DVDs is highly variable! Some discs are excellent, some are crap. And it seems to be pretty consistent with the company that distributed them too. Some discs read very smoothly while others require all kinds of speed adjustments by the drive to get data out of them.