Storage: Do burned CDs and DVDs have a shelf life?
- 2/13/09 2:55 PM
Do burned CDs and DVDs have a shelf life?
by Lee Koo (ADMIN) - 2/13/09 2:55 PM
Questions:
I've been backing up my important files on recordable CDs and DVDs for a quite a few years now. However, the other day my friend told me that he read some article explaining that burned CDs and DVDs, while a reliable backup method, do have a shelf life and one day they will fail to read and that I should make duplicate backup copies of my files on another media or external hard drive just in case. This is new news to me, but paranoia still set in! I went immediately to check on a few of my backed up CDs from many years ago dated 1998 and 1999 and was relieved to find that they read perfectly fine from my PC. Now I'm questioning if what my friend read was a myth and I'm turning to you for answers. Is it true, will burned CDs and DVDs eventually become unreadable? If there is a shelf life, what is their expected life span? Are there better quality CDs or DVDs recordable discs that are better for longtime storage? What is the best way to store burned disc to prolong shelf life, if there is such a thing? Am I being paranoid for no reason? Have you had any old burned CDs or DVDs fail on you because they were too old? Sorry for all the questions. Thanks for any facts you can provide.
--Submitted by Michael D.
Here are some featured member answers to get you started, but
please read up on all the advice and suggestions that our
members have contributed to this member's question.
CD/DVD shelf life --Submitted by Zouch
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2966806#2966806
Longevity of optical media --Submitted by Watzman
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2966751#2966751
Life depends on quality--here are my experiences --Submitted TonyGore
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2967126#2967126
To read or not to read? That is the question. --Submitted by Starkiller5
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2967968#2967968
Do burned CDs and DVDs have a shelf life? --Submitted by explorer2_000
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2966896#2966896
About CD/DVD lifespan --Submitted by mssusanf
http://forums.cnet.com/5208-7588_102-0.html?forumID=70&threadID=327942&messageID=2967294#2967294
If you have any additional tips, knowledge, or experience to share with Michael, please click on the reply link below and submit your answer. If you have links that will help with this topic, please do provide it in your submission. Thank you!
burn cd
by gselby4 - 1/30/09 6:03 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I have cd at speed 8 Had a life of 5 years as I had mp3 on them an they went south in the year 2000.Wayne
CD Life
by Philbeeus - 1/30/09 6:14 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Last fall I took a class on photos and our instructor said that you should always store them on edge and any time you made a change in the system to make a new master and throw the older one away. He suggested replacing them every five years. Its a small thing to do and not worry about losing anything.
I dont think so
by Pinda - 1/30/09 6:18 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
The only problem I can imagine is of they get scratched or damaged. Ive never had one go bad because its old. I have LPs Ive had for 40 years that are fine, if they can last I cant imagine a CD going bad. Id just be careful how you store them
most CDs are metal films, LPs are not
by Culebra - 2/13/09 6:33 PM In reply to: I dont think so by PindaYour belief that CDs can last as long as LPs is, unfortunately, totally incorrect. Ever notice what happens to metal objects ? Over time they corrode or rust (i.e., oxidize ). This is a chemical reaction which is unavoidable, except if your CD is glass or gold (which does not oxidize). Most CDs are comprised of a thin aluminum layer on a thick plastic base. The aluminum oxidizes.
Yes, LPs will not have this problem. But ... CDs will *definitely* go bad -- just a matter of time and how much exposure to heat, water, air, and other substances which can accelerate oxidation. For example, CDs will go bad faster in the tropics than in Canada. (10-15 years)
YES!!! CD's do have a finite shelf life.
by john3347 - 1/30/09 6:20 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I have personally had information begin to evaporate from CD's in less than 5 years. This has happened with more than one CD, but with several CD's that were 4 or 5 years old. I do also have some that are more than 8 years old that still have information intact. It is my understanding that if CD's (I assume this also applies to DVD's, but I have not had personal experience with DVD's.) are stored in an ideal environment (dark, dry, cool but not cold, etc) they will have a life much longer than some of mine which were exposed to sunlight, cold and hot conditions, and other conditions that portable media is subjected to. When I burn a CD or DVD, I date it with the month and year and I make a new copy and discard the old one every 3 years or so.
I really do not fully understand how what I am going to say here works, but it is my understanding that commercially produced CD's and DVD's are created by a different process than computer generated CD's and DVD's and have a much, much longer shelf life than computer generated media. I understand, however that even these cannot be expected to be readable when 30 or 50 years old.
That's my story, and I'm stickin' to it!
Manufactured CD's & DVD's
by foxwood farm - 1/30/09 8:22 PM In reply to: YES!!! CD's do have a finite shelf life. by john3347I saw a TV show a few months ago and they showed that the factory CD's & DVD's are pressed like a record. They make a steel master containing the pits and bumps and press it into a blank disk
Yes, CD and DVD's re mechanically pressed with pits and...
by AnthonyNYC - 1/31/09 9:59 PM In reply to: YES!!! CD's do have a finite shelf life. by john3347Like the other guy stated, the commercial cd and dvd's are pressed like a vinyl record so it is physically pushed into the material to create the pits and vallies that the laser reads as 1's and 0's.
A cd-r or DVD-R is made using a laser to etch the spots into the material and the problem is oxygen gets to this material and eats away at it over time, oxydation, like rust destroys the data so the disc can no longer be read reliablly. The name for this is disc rot, and it is documented, try googling it.
I wonder if storing your important cd or dvd's in an air tight plastic container or say a vacumm sealed bag would help?
It theoretically should keep the oxygen out, right?
Pressed CDs ROCK!
by vattan2005 - 2/13/09 8:55 PM In reply to: Yes, CD and DVD's re mechanically pressed with pits and... by AnthonyNYCThank you, AnthonyNYC. Now, I know why I have not had a single, not ONE, pressed commercial CD fail on me in the 26 years I have had CD's! However, many burned CD's and DVD's have failed quite frequently. Nowadays, I use Fuji (probably one of the top brands) to back up, create at least 3 copies of each for redundancy, and keep a final backup on hard drives. Works for me!
CD's and DVD's life
by jerry3525 - 1/30/09 6:20 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
The typical shelf life of CD's and DVD's can range from 5 to 10 years. The quality of it, temperature, humidity, and handling, all affect the life of the CD or DVD.
CDs and DVDs have a shelf life.
by Anton Philidor - 1/30/09 6:25 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Though some last longer than others, they will become unreadable to Windows. Especially RWs which you have erased and rewritten and added to a number of times.
There is software to read these CDs and DVDs when Windows will not, and you can usually rescue the material on the discs.
I recommend Isobuster (free for this purpose), which has been able to recover most of and usually all the material by going over and over the material in damaged sectors.
(I first learned of this from someone in Support at Nero, though the company now has its own disk rescue product, which I haven't tested.)
http://www.isobuster.com/
Also useful for damaged audio CDs is EAC (Exact Audio Copier; also free):
http://www.exactaudiocopy.de/
It's also good for undamaged audio, but more time consuming than CDex.
I'd advise making certain your material is readable every year or two, and consider using a dedicated external hard drive as an alternate backup.
Free IsoBuster?
by pie guy - 2/22/09 10:08 AM In reply to: CDs and DVDs have a shelf life. by Anton PhilidorI went to the IsoBuster website and it is $29.95
Longevity of optical media
by Watzman - 1/30/09 6:30 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
This subject has been dealt with at length previously, in fact I wrote a response to a similar question in 2006 that "won" that weeks response award (it was the 1/27/2006 column, if you want to look it up).
In a nutshell: You are PROBABLY being paranoid.
The best information available (and it's definitely somewhat limited since CD-R has only existed now for 14 years or so) is that QUALITY optical media burned on a quality PROPERLY WORKING drive, will last at least 50 years and some estimates go out to 300 years, based on the best avaialble lab work and analysis (it goes without saying that no one has been able to test even 50 years in real world conditions).
Now, however, a bunch of caveats:
1. Media: There is good media and there is junk media. And there are dozens of different dye formulations in at least five major dye families (if you care, they are Cyanine, PhthaloCyanine, Metallized Azo, Advanced PhthaloCyanine and Formazan). These all have significantly different characteristics (they WILL have different lifes), and each of them can be made into a "quality" or a "junk" media of that type. I guess it goes without saying that junk media, of any type, is just that .... junk.
2. Drives: There are good drives, there are bad drives and there are good drives that have become defective. It is my personal opinion that a lot of the problems that we have are caused by drives whose laser output power levels are below spec. That can happen even to a high quality drive that was once good (it can also happen simply because the optics have become dirty). So the media isn't heated to the proper temperature, the dye doesn't fully change it's reflectivity and you get a burn that consequently has poor long term stability. So the moral of this story is that everyone who has an optical burner should have a laser power meter and use it regularly (just kidding .....).
3. Storage and handling: This, too, effects life. Temperature, humidity, handling, storage type (it's better to store discs vertically; DVDs should not be flexed (including as in removing them from a case), scratches can do obvious damage, etc. etc.
So you put all of those factors together and they all impact the life of your media. The estimates of 50 to 300 years were for quality media properly burned and properly stored. There is no absolute guarantee that any of us real world users will meet any of those critera much less all 3.
So what is the bottom line? Here is my conclusion:
All indications are that properly burned optical media will last for decades.
However, as all kinds of backups do fail, I ***ALWAYS*** have multiple backups. And I think that is one rule that applies for all backups of all types. One backup, even two, is NOT enough.
***NEVER*** use "RW" media (CD or DVD) of any type for anything that you plan to keep. Only use "R" media. Sorry, RW media just is NOT stable, I've had too many bad experiences with it in my 40+ years in the computer industry (only 10+ dealing with optical media, but that's enough for me .... I've seen a years long clear pattern emerge).
After using a drive for a while, and after using media that it has burned in other computers with other drives, you will get a sense of whether or not the drive is reliable. Pay attention to that; signs of unreliable operation (especially problems reading discs later, either in the same drive or other drives) should not be ignored. FWIW, I've had the best luck with Samsung (now TSST) and Pioneer and, frankly, much worse luck with almost all other drive brands (and I build and service computers, and this is based on hundreds of drives that I've dealt with).
Also, you mentioned "shelf life" in your query, that really would refer to the time BEFORE the media was burned, the time between when you bought the media (really, when it was made) and when you burned it (the time subsequent to burning would be the "archival life"). Shelf life is limited, optical media should be used with 5 years of it's date of manufacture, although in general we have no way of knowing when the media was made, but usually it will have been bought within a few months of manufacture.
Hope that this helps,
Barry Watzman
Err on the side of caution
by john3347 - 1/31/09 3:43 PM In reply to: Longevity of optical media by WatzmanI do not explicitly dispute anything that Watzman has said here......BUT!!! Are you ready to bet your grandchildren's baby pictures that you have used "top quality" media (how can you distinguish top quality from mediocre?) and that you have a "top quality" CD drive and it is functioning perfectly? I certainly don't want to burn all my grandchildren's baby pictures to a CD and file them away in a box on a closet shelf expecting to pull the CD's out to embarrass the grandchildren with when they come home from college 20 years from now. (MUCH LESS 50 to 300 years)
I cannot vouch for "quality" of media or "quality" or condition of CD drive, but I have had pictures, saved documents, and data(OS back ups) disappear from CD's in LESS that 5 years!!!!!
Top Quality
by mwooge - 2/2/09 7:04 AM In reply to: Err on the side of caution by john3347> (how can you distinguish top quality from mediocre?)
Buy name-brand CDs and DVDs. Those'll be top quality or close enough. Don't buy cheap. You get what you spend for.
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