Expected life of CDs/DVDs? - Page 1
Forum section: electronics / general

author: brainwash
author_rank: Frequent Contributor
timestamp: September 08, 2013, 06:06:10 pm
content: I was just sorting through my >10yr DVD collection and transferring some of them on the NAS. I've probably copied around 30 DVDs and at least 3 of them are partially unreadable. Luckily, important data has been at least duplicated, but I did not expect failures so soon.Causes:- scratches, caused by hauling them around (change apartments a lot) in the spindles- discoloring, seems like sun burns but most of the time they were stored in darkness- no visible damageI haven't finished copying all the DVDs but I've taken a look at all of them and expect perhaps a 5% failure rate. That's pretty sad.Except duplicating over and over the same information, filling up harddrives and sending them away and keeping live copies around, what are archival options are there?

author: IanB
author_rank: Super Contributor
timestamp: September 08, 2013, 06:13:00 pm
content: Are they DVD-R discs, or DVD-RW?I would be less surprised about re-recordable discs failing than write once discs.

author: brainwash
author_rank: Frequent Contributor
timestamp: September 08, 2013, 06:18:41 pm
content: DVD-R, most of them were written quite some time ago (1997-2003) when DVD-RW were not so prevalent.I do have a few CD-RW and DVD-RW from around that time, only lightly used and they are still readable. Too few to actually draw a conclusion.

author: Thor-Arne
author_rank: Unknown
timestamp: September 08, 2013, 06:20:57 pm
content: Difficult to answer.Some manufacturers claim life expectancy for recorded disks to be 30 to 100 years (sourcetheXlabs), but theNational Archivesclaims to have experienced 2 to 5 years.

author: SeanB
author_rank: Super Contributor
timestamp: September 08, 2013, 06:26:09 pm
content: Depends on the make of disc. I tried reading some Verbatim CDR's that were made in the late 1990's on an old HP external writer, and the data was perfectly readable. Some made last year are not, but they were mostly scratch discs for transferring data to old computers without USB drivers ( win98 machines that were being updated slightly) that understood large discs.Verbatim Datalife were about the best, but they stopped making them. The no name ones you buy on a spindle vary a lot from batch to batch, even from disc to disc in the same 100 pack. Best way is to make 5 copies of the data, using multiple small files. that way you at least are able to do data recovery.I was able to read off the Verbatim discs a 650M QIC image with no problem, but as I did not have a working copy of the particular Microsoft backup to hand easily I just copied the huge file, then did a secure erase on the CDR with the microwave oven. Dumped the file, as I was just checking what was on the disc before tossing it. Even some I made with the rerecordable Verbatim discs ( which were used as daily backups and were cycled on a 2 week rotation so had upwards of 100 write erase cycles on them) were readable. Overtaken by tape when the data exceeded 700M and i got tired of doing 2 backup jobs. Big tapes, they took a whole 1G compressed.......

author: IanB
author_rank: Super Contributor
timestamp: September 08, 2013, 06:31:20 pm
content: 2-5 years is depressing. That's not very good for long term storage.I read many years ago that the quality of the plastic in the disc is a big factor. If plastic is low quality or contains impurities it can "rot" over time and lose its integrity.

author: mmagin
author_rank: Frequent Contributor
timestamp: September 08, 2013, 06:41:22 pm
content: If you don't use the drive a lot, I'd advise gently dusting it out with one of those cans of dust-off that has a tube on the end that you can use to direct the blast.I was having trouble ripping CDs on my Mac Mini and this solved my problem. Considering how I never use the drive otherwise, and there's also probably negative pressure at the slot that faces the outside (due to an exhaust fan elsewhere in the computer) it's no surprise it was dusty.

author: brainwash
author_rank: Frequent Contributor
timestamp: September 08, 2013, 06:45:19 pm
content: I'm going through a lot of duster cans. They're even good for removing ear wax, but don't tell this to my doctor.

author: Thor-Arne
author_rank: Unknown
timestamp: September 08, 2013, 06:58:06 pm
content: Quote from: IanB on September 08, 2013, 06:31:20 pmYes, very depressing.I initially heard that CD's/DVD's was reliable for 10 years, luckily my backup routines are so good that when the CD's failed before that time the files was still intact on hard drives somewhere.Everything is stored on external drives now, and the important files is stored on 2 external drives (one off-site), on 1 NAS and both of my laptops.For smaller files flash drives and/or DropBox can be a good idea, for media (photos in my case) these are either to small or to expensive.

author: quarks
author_rank: Frequent Contributor
timestamp: September 08, 2013, 07:31:43 pm
content: With trying private Long Time archiving of digital data, you have to be prepared to loose (sooner or later) access to your data.If your data is of any value for you, make several copies on different media. Make yourself a reasonable datamigration plan for the years you want to be able to access your digital data. Also it is worth to look for Special Archive Media CDs, DVD-RAM, MO (one of my favorites but unfortunately obsolete) and the DVD compatible MDISC (Marketing talks of up to 1000 years). Do not have just one last single archive copy on one media.Self burned DVDs (-R, +R and especially RWs) are in gereral not good for archiving (CD-Rs are a little better/safer, but also not really good).Expected life is very hard to tell. If you do not verify your burned disk after writing, it can already be damaged from the start. If everything went well, you have to store the Disks safely (avoid thermal and mechanical stress and humidity). With that my guess is, you should check the data at least after 3-5 years and start to migrate.

author: MacAttak
author_rank: Unknown
timestamp: September 08, 2013, 08:29:37 pm
content: If you really care about it, then get out of the business of managing your own data redundancy. Amazon S3 provides standard storage at a maximum cost of $95/month per TB, or as low as $10/month per TB for the "glacier storage" which has a ~3 hour restore time period before you can retrieve it.Let them worry about detecting media failures and redundancy.If these are personal video recordings, then the cost is probably worth it to you.Then again, if these are 10 year old pirated movies (you mention that most are DVD-R) that you downloaded from the internet, why in the hell are you hoarding it? Watch them and move on with things. Or at least don't fret about losing 5% of something that you didn't pay for in the first place.

author: brainwash
author_rank: Frequent Contributor
timestamp: September 08, 2013, 08:50:24 pm
content: Wait, what? If I need to pirate movies I can just watch them online. DVD-R is just a medium format.Cloud? No, thanks, that's less reliable than anything above and completely out of your control. I'm talking saving memories for a lifetime not until the next company strategy meeting.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: September 08, 2013, 08:52:27 pm
content: There have been a few fungi and bacteria that have been discovered that have severely limited the life of media. Some eat the plastic, others the bonding between the plastic and aluminum, others the rewriteable media. I seem to remember seeing a discussion where this is one of the major reasons for the large discrepancies between advertised life and real life. When the lifetime studies had been done, these pathogens were not widespread. They were first discovered in 2001 from Belieze. Since then, more have been discovered.About backup methods, level of extremity is based upon the necessity of keeping the data. At my parents office, their patient records are their lifeblood. We have three total backups methods because if they lose the patient records my dad would go bankrupt. THe first two are linked. We have three USB HDD which at anyone time two are in a lockbox at the bank the other does daily back up for a week until it is switched out with another one at the bank. This way at most even assuming a system failure PLUS two of the backup drives fail at most he temporarily loses two weeks worth of data. So level 1 backup is the daily, level 2 is the ones in the lockbox, the third is offsite. This backup is automatic, its fully encrypted to meet HIPPA requirements, etc. THe problem is it might take some time to retrieve the backup. This may seem extreme to many but if they lose those records my dads livelihood could be toast.

author: mcinque
author_rank: Unknown
timestamp: September 08, 2013, 10:51:44 pm
content: Some years ago I've read an interesting article on a national specialized magazine that has introduced some benchmarks results about the life expectancy of CDs.The results was ten years tipically, and they are influenced bywritable layer materialwriting speed (less speed means less writing errors and more space for correction bits)storage (humidity, temperature, UV rays)type of protection of the upper writable layerI've seen many early cheap writable CDs (expecially Verbatim) with upper layer delamination after about 2 years, while the good old 2X Kodak GOLD Writable CD, with a good quality protection layer over the top, still readable after 15 years.The only sure thing is that you cannot trust in that kind of support: only the old tapes will last for 3 decades! Guaranteed.

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 08, 2013, 11:00:08 pm
content: Beware! DVD+R(W) has a different (better) error correction scheme than DVD-R(W). Neither is suitable for archival.At this point there does not seem to be any suitable cost-effective archival recording scheme on the market. Spinning disks have a pretty good size and cost advantage over anything else at the moment.Some tapes are in fact readable after 30 years, others not so much.At least one of the "cloud backup/archival" companies has gone belly-up due to hardware failures and inadequate backups. Anybody depending on that company's services for primary storage lost their data. The privacy of data stored in "the cloud", even if encrypted, must not be overestimated.Relevant discussion about archival media on another forum.

author: staxquad
author_rank: Frequent Contributor
timestamp: September 08, 2013, 11:05:26 pm
content: I miss Kodachrome

author: brabus
author_rank: Frequent Contributor
timestamp: September 09, 2013, 09:28:49 am
content: My car satnav needs a dual-layer DVR+R for the maps. Result: I need to write a new disc every three months.I buy first quality Verbatim discs, write them very slowly with my NEC DVD writer... what's wrong with them?I suspect thermal cycling in my car is cuplrit for this, because all other DVDs I wrote (ank kept in dark closets at home) are still readable after 5 years.Yes, they are single layer DVDs, so they can be more robust, but... only 3 months for the DLs?

author: jahonen
author_rank: Super Contributor
timestamp: September 09, 2013, 04:06:14 pm
content: There is alwaysPaperbak. Although physical storage space required might be uncomfortably high.Regards,Janne

author: vk6zgo
author_rank: Super Contributor
timestamp: September 09, 2013, 04:30:51 pm
content: Quote from: staxquad on September 08, 2013, 11:05:26 pmYes,I still have colour slides from 40 years ago which have been stored poorly,but have not lost either their colour balance or resolution.The best ones are the now defunct Anscochrome.

author: mcinque
author_rank: Unknown
timestamp: September 09, 2013, 04:33:21 pm
content: Quote from: dfmischler on September 08, 2013, 11:00:08 pmTrue!Quote from: brabus on September 09, 2013, 09:28:49 amThermal cycles are a good killing methodQuote from: jahonen on September 09, 2013, 04:06:14 pmBrilliant!