I think most of us have had the experience of losing data on CDR's. Is there any reason to believe DVD-R's will be more reliable, or do you think we will just lose 7 times the amount of data when the disc is unreadable in a year?

Any experiences yet?

DVD-R does have better error correction than CD-R.

yeah, but it is necessary because the physical representation of the data is so much smaller, and a scratch of a given size will cover more data on a DVD than on a CD. So while correct, it may not *necessarily* mean DVD is safer. There's more to it than just simply having more error correction, you have to look at why it has it, why it needs it, and other variables too.

If the error correction is better that's good, however if the disc is damaged you'll lose that much more data.

I think that data lose can be combated by making two copies when archiving and only using one of the copies whilst storing the other away and only using it if needed.

Good point.

I have some badly scratched DVD's that still work fine. If these were CD's i would be throwing them in the bin

I've only got two DVD-R from december 2002 that still play well. But I can say the same about CDRs.

If we talk about CDRs getting old and unreadable without physical damage, storing two of them in two separate places doesn't help at all, there was only several monthes of difference between the the time the ones stored in my home got dead, and the time when the ones in my father's home did. It only helps if one get scratched or lost. When one gets unreadable after time, you can bet the one you stored elsewhere is dead too.

About the better error recovery, it won't help for aging. Once an audio CDR gets errors, they quickly progress and rise, until, after several monthes, they get to the state represented in this post :
http://www.hydrogenaudio.org/forums/index....8482#entry87200
where 176400 bytes per second are lost, that is the totality of the information that was present.
For an audio CD in this drive, it represents more than 4 destroyed bytes in every 24 bytes frame. If the number of destroyed bytes per frame is subject to statistical variations, it means that the average amount of lost bytes is significantly bigger than 4 bytes per frame, so that the bottom value never gets under 5 per frame. It must be 50 % of the raw data or more. And looking at the curve and the aging rate, it seems that 100 % destruction is very near. If it's not already the case at the end of the CDR, it is just a matter of monthes.

I too worry about data loss and have wondered about a better way but I may be worried for no reason. I have not had data loss after burning maybe thousands of cd's and this includes using the good ol' bulk cdr's. Though, I stepped on one in the driveway and a track would not play.
I do wonder what is a realistic life expectancy for cdr's?

Realistic ? User report lifespan from dead-after-one-week to alive-after-8-years.

In your opinion, what would be the best to get? I have been using Fuji's for about a year with no problems. I got them as for me they had the best compatability. Though, I am willing to change.

I am willing to know too wich one have the best life expectation, no matter of the price,

Soren

Fuji's are good as long as hey are made by Taiyo Yuden.

http://forums.afterdawn.com/thread_view.cfm/3247

You can also find a thread there where I report gold CDR all OK while Silver CDRs with the same history, and from the same manufacturer, are dead, but gold is not the definitive solution, since you can find some gold CDR dead too in the above thread, with good descriptions (no scratches, no damage, developed slowly more and more errors in an unexpected way...)

I've had CDR's that were bad immediately after burning them. I would not notice this with audio CD's, but if I had data CD's with SFV or MD5 files, I would find the read problems if I tested right away.

After examining these discs, I could see problems in the material. I've seen black spots. I've seen areas that had a kind of cloudy appearance. I've seen small pinholes. All of these defects are actually inside the material.

I had these problems with Sony, TDK, Memorex, and probably a few others. It's not time and wear that is causing these discs to fail. They are bad out of the box due to a cheap faulty manufacturing process.

I've also had discs just wear out from old age.

Edit: with audio CD's, I would find the problems doing a secure mode rip with EAC.

I haven't lost any data yet with cdrs but weird

my cdr sometimes acessible and sometimes only a quarter of the cd is readable and even unredable!
its the same cdr with the same Samsung drive.........

edit: not [quarter] its session

Could anyone pls tell me why would this error occur?
Is samsung' laser's bad?

Besides, my samsung SC-152L could not handle cd-rw (Yamaha) in cd-mrw format properly?
any solutions?

Thanks in advance......,

Store the files on cds with a small amount of parchive2 files (about 20mb) with a small block size 384,000 bytes or less, so if a few of your mp3's got screwed you can recover them with the par files.

I have experimented with that. If I have all of my MP3's in one directory, I can make PAR files to protect the entire CD very easily.

But I put my MP3's in separate directories on the disc. I have not found an easy way to recurse the subdirectories. Without that, I have to go into each directory and create the PAR files.

I'm probably missing something.

I'm confused. I never had data-loss on a CD-R, if the CD-R hadn't any scratches.

You're one of the lucky ones. If you burn 1000 CD-R's. You will have some that are defective.

It's a real conundrum allright.
CD-Rs can go bad at almost any time, some of my worst examples have had the aluminum reflective layer start to flake off after a few months. Avoid unbranded bulk silver CD-Rs at Fry's!
I don't anticipate DVD-R, +R, /R, $R or *^()R will perform any better on average, and I've had too many hard drives die to trust them completely.

Maybe a RAID 1 array in a temperature controlled safety deposit box?

Has anyone reported any dead DVDR's yet?

This is an interesting problem and very important to professionals dealing with inexpensive storage media such as cdr/dvr which are intended for long term archival.

I have burned CDs since 92, but unfortunately don't have access to the oldest burns anymore.

Some of my stuff from c. -96 is still perfectly ok, without a single C2 and very low C1 count (consumer test with Kprobe/LiteOn cdrw). Other burns from only two years ago I cannot say the same.

I've seen lots and lots of 'brand' and non-name media fail after a few months to a couple of years. Examples:

- Kodak Gold: label side/reflective side peeled off = totally unreadable / all data lost
- Fuji: UV light made the disc unreadable in less than a week (when tested particularly for UV resistance) = all data lost
- no-name media developed lots of small pinholes in the reflective layer (oxidization?) = data mostly unreadable

The discs above were stored properly in proper temp/humidity/safe from scratches (only Fuji was exposed to sunlight for UV resistance testing).

I hope there was a lab that was interested in simulating the aging of various cdr discs and how it affects their readability.

I tried to set up a proper home made test to gauge various brand media longevity/readability, but eventually realized that it has way too many variables to be controlled in a home setting.

I'm sure there are thousands of archival professionals and perhaps even millions of consumers who would be interested in finding out what kind of media has a better chance of surviving the next ten years.

regards,
Halcyon

the quality of dvdr's probably vary more than cdr's. about 10% of my memorex dvd+r spindle was defective. but the dozen or so memorex dvd+r 3-packs i bought were fine.
i heard a lot of complaints about defective/incompatible dvdr's. as with cdr's you should go with a good brand name.

my experience is as follows:

Taiyo Yuden from 98 (Sony) --> No C2 errors, small rate of C1 errors (Max 60, ave 1.07).
Taiyo Yuden from 98 (Sony) horribly scratched --> No C2 errors, huge rate of C1 errors.
Ritek from 2000 (Memorex) --> Unredable, the C2 graph looked like the latest Oasis record on wave view.
Ritek from 2000 (Memorex) --> Redable, lots of C2 errors.
Verbatim DataLifePlus (MetalAzo) --> the last 5 minutes where unreadable inmediately after burn.
Taiyo Yuden from 2002 (Fujifilm) --> No C2 errors so far, the C1 count is very low (Max 13 errors, ave 0.34) .

This test was done in January 2003 with a LiteOn 32123S.

Pio: any dead TYs yet?

@/\/ephaestous: This is all new to me so bare with me. How can you tell that a name brand (fx Sony and Fujifilm) is actually a Taiyo Yuden?
Do I understand right? Sony and Fujifilm CDRs are the same (both being TYs)?

Sony seems to [have] be[en] a decent brand. The actual Sony manufactured discs are similar rates from similar ages...


The older Lite-ons (<40x)? have problems with the DataLifePlus discs. I know my 24x one does, and someone reported a while back that the 'Grade B' Datalife discs actually gave lower error rates.

Maybe there is a firmware to upgrade? I'll have a sniff

From the FAQ :

http://www.cdrlabs.com/phpBB/viewtopic.php?t=7280

That is the real question.

Not to my knowledge, but I left Afterdawn, CD Freaks and CDR Labs a bit, recently.

The fact that upon a quick glance around, I cannot find any reports of any (other than standard 'didnt burn it right - dont work' stuff). This is a very good sign in itself; as Pio stated, some CDR's die within days / weeks. We'd have heard about it if DVDR's had already gone belly-up.

would'nt Flash memory be the most reliable storage medium? I know it would be expensive though. DVD-RAM is the most reliable disc storage medium, its protected in a case and offers very good defect mangement and can be used like a Hard Drive, and i think there is double sided DVD-RAM which holds about 9.6 gb ?

protected in a case? how is that? i have a maxell DVD-RAM here, and it looks like a DVD-R/RW ... why would it be more reliable?

More reliable becus its in a case!!! you can take it out of the case though and DVD-RAM was designed to be the most reliable. This from taken from another site.

Although a tremendous amount of data is packed into a small space, you shouldn't experience any problems with scratches and other physical damage. In the first place, the media is packaged in a tough plastic cartridge. The Type 1 media remains in that cartridge forever; the Type 2 can be removed and can be used in some dual purpose CD/DVD drives. But more importantly, the DVD error correction is said to be 10 times better than that used with CDROM's. When used for backup, where there would be no reason to ever remove the media from the cartridge, errors should be effectively non-existent.

Because of the extreme expected life (100,000 writes is 273 years of daily backup!), media cost should be far lower than tape (which typically will survive only a few hundred writes) - in fact, these units could pay for themselves in just a few years in many locations.

Looks like a big floppy -> http://www.digital-photography.org/DVD-RAM...ProDirect_2.jpg

blueray disc -> http://www.cdrinfo.com/Images/Uploaded/max...luRay_discs.jpg

Some info here http://www.cdrinfo.com/Sections/Articles/S...%2DRAM&Series=0

Since I'm quite pleased with how my cdr's have served me (since 1998), with close to <5 media failed over more then 1000 burnt, I want to know just one thing:

On a theoretical level only, if I would store 2 discs, one is cdr, the other dvd-r, in an normal storage condition (aka, no scratches, no extreme conditions like exposure to sunlight, etc) and both media's are of the same production quality, will the dvd-r will perform worse/better/or the same as the cdr will?

hard to say. even if the only difference is dye degradation there's more than simply that to consider. The DVD's "pits" and track is smaller and more closely spaced, so 'per area' it is more susceptible to dye degradation. But it also has more data redundancy in its error correction scheme than the CD does.

dvd-ram is not always in a case. they have regular discs also. just clarification.

Here's some interesting information about the topic from Australian Personal Computer Magazine - tests and technical/economical backgrounds.

One intersting detail (out of many):

Memorex DVD-Rs. one bad experience with an entire 5-pack, but will never buy their DVD-Rs again.

i bought a 5 pack just when DVD-Rs were dropping in price (woo! $6 a disc! what a deal!), i'd say fall/winter; none readable today. one even failed as the lead-in was being written.

all the others burnt around the same time (yeah, my sorry ass using my friend's DVD burner ), Sony, Fuji, TDK (possibly fakes), a near smooth diagonal line in CD Speed a month or so ago. all burnt at 1x on an A04. the only thing to note would be that all i burnt were DVD-Videos, but that shouldn't make a difference. they're burnt no differently AFAIK than data, unlike VCD/SVCD which is burnt with less ECC but with an extra 100 megs gained.

now that i have a standalone DVD player that can read just about anything thrown at it (an Apex AD-1201 and fugly as hell) i don't have to worry so much about buying specific media, but i was buying Verbatims (for school projects) and Accu 1x (Lead Data when read by DVD Decrypter) as cheapies for any other DVD-Video. I still buy Accu but am trying out Ritek G03 for DVD-Video and other stuff i don't entirely mind losing, and Ritek G04 (4X) for Important Stuff

just so you know, it's prolly best to only burn 3.8 gigs or so, that's where cheapies tend to get unreliable (if the disc isn't entirely, anyways), and on the very rare occasion (like 1 in 20 or 30) the 4X Riteks.

as for Prodisc, i've heard enough to make me not want to use them, no to mention the video production company i'm interning at has had a few bad discs (even mastered a movie on one of them and couldn't figure out what the DVD duplicator robot keep spitting discs onto the floor).

www.dvdrhelp.com > dvd media >> taken with a grain of salt, of course.

I've gotten into the habit of adding an MD5 checksum file to every disc I burn. I always run the MD5 check after the burn process to make sure everything is OK.

Most of the bad CDRs I have had were probably bad right from the start, so maybe this will protect me from that. I hope.

Partial solution -- buy only high quality CD-R (and DVD-R) media at premium prices, perhaps in bulk to save some money (best sources are online, imo). Chances are, this media will last longer and have lower error rates. If your data is important to you... what can I say...

If someone wants the results of the last c't mag review, they tested DVD+R/RW's and DVD-R/RW's with an expensive hardware tester.

All DVD+R media is more or less good, because of the rather strict testing conditions of Philips Licensing. Most of the DVD+Rs/DVD+RWs available are manufactured by Ricoh, followed by Taiyo Yuden. Mitsubishi also makes some (Verbatim), which are usable too.

DVD-R discs are much more diverse. On one hand, good results from Mitsubishi (Maxell DVD-RW 2x) or TDK (TDK DVD-RW 2x) media, but shockingly bad results from Princo (Princo DVD-RW 2x) or Mitsui (MAM DVD-R 4x). Add to that that even media that is recommended by several drive manufacturers has completely different results in three different drives (bad burn / very good burn / very bad burn, for instance). It seems that the firmwares of some drives are not very optimized yet.

Also, c't found out that especially DVD+RW's should be recorded very even and not partially. If it's always burned only partially, the drive can't adjust the write strategy accordingly (Running-OPC), because the dye properties of previously written vs. previously unwritten parts of the disc are too different. Also, 1000x rewrite is a myth, since the error rates are way beyond spec after that. Realistic is 500x rewrite.

have you actually sat there and burned/erased a disc 1000 times?

my worst experience with shitty cdrs was with PLATINUM. they were partialy or completely unreadable a few month after burning them. my best experience was a VERBATIM, burned 6 years ago and not one damaged sector today.
i do also think about getting a dvd burner soon, so it interests me too, how reliable dvd+/-rs are. not how many scratches they tolerate before they can't be read anymore, but how long the material stays readable..

-andy-

Yes, they did, with all DVD+RW's and DVD-RW's, with 400 MB of data burned 1000 times each.

Chip, a PC magazine in Germany had a test of 4x DVD in 11/2003.
They made tests in a climatic chamber to simulate a 3 year aging (100h at 80°C and 85% air moisture).
They measured the inner, center and outer area of the DVDs and compared the errors when the DVD was fresh and after 3 years.
Unfortunately they don´t have the complete test from the magazine online, but the charts.

CHIP DVD chart
uncheck "nur Top Ten anzeigen" or click "alle" inthe left lower corner to see all results.

The values column under "Messtech." are representing the reliability.

We must not trust these kind of tests. We saw that for CDRs, they lead to a lifetime estimation up to 50 times the real number.

They give 70 to 200 years, while CDRs can often last less than 4 years.

could you explain how you do this?

I have the directory structure setup on the hard drive. I use some MD5 software to scan every file and every directory, which then creates the MD5 file in the directory root. I burn that file to the DVD with everything else.

After the burn is done, I run that MD5 file, from the DVD, and it scans thorugh every file on the DVD and verifies it.

Kinda slow. A full DVD will take about 10 minutes to verify on my system.

Without plugging any particular software, this is one I have used for this:

http://www.irnis.net/soft/acsv/acsv_main.gif

Edit: URL

Oh damn, I wish I'd read that before I ordered a pack of exactly those Mitsui discs a couple of weeks ago.

That'll teach me to automatically assume "Mitsui = TEH QUALITEY" without any research in the future...

Err.... Not that I doubt your results or anything, but I was under the impression that Taiyo Yuden made DVD-Rs, not DVD+Rs.