To verify, or not to verify... that is the question

OK, no this is not really a newbie question per say… In fact I’d really like some expert advise… But since I didn’t see any other section that seemed really appropreate I decided to start here…

Now, my understanding of ‘verify’ option of Nero or other burning software is… that the data that gets burned to the DVD/CD is read back and compared bit by bit to the original data. At least that’s what I assume it does, as anything less extensive would be worthless to me.

Then there is scanning… My understanding of scanning, is that the scanning software tells the DVD/CD drive to ‘read’ the information on the CD or DVD, and the drive reports to the scanning software of any PIE/PIF or C1/C2 fallures, etc… however it does not compare the data to the original, or for that matter, it doesn’t actualy do anything with the data… Just tells you if the disk is readable by the Burner/reader… You can use this to judge the quality of the burn, and hopefully do tell me something about the long term readabilty of the burned disk… but it doesn’t tell me if my data is accurately copied…

So… My main purpose for burning DVDs and CDs is for long term archive of digital photos. My desire is to be able to remove the data for these photos from my hard drive, and use DVDs and CDs to store ALL of the original photo images I take. Now, it’s critical to me that this data be accurate, and readable for as many years as possible… With my sincere expecation that I could read this information of the disk in 10, 20, 30, or so years from now… Now I’m making mutiple copies, to help insure at least one copy will survive over time.

My problem… is TIME… Currently I’m burning a copy on CD, and a copy on DVD… I’m seriously considering burning a third copy on DVD that I can take to my parent’s house, and store there, which would protect from some major catastorphy at my home, like fire for instance…

At 48X I can burn and ‘verify’ a CD in about 7 minutes… A scan at 48X probably takes something like 4 minutes from start to finish. So if I do all that, I’ve got close to 15 minutes of my time tied up.

At 8X, I can burn and verify a DVD in about 20 minutes, and a scan probably takes at least 10 minutes at 8X. So I’ve got about 30 minutes into this process…

So… I shot 10,000 photos last year… the data is about 8MB/image, so I’ve got like 80G or close to it of data I need to archive each year… that’s about 120 CDs, and 20 DVDs… (another 20 DVDs if I make another copy to take to another location)… So I’ve got at least 40 hours a year tied up in this process…

So… is it safe to eliminate the ‘verify’ part of this process? (my gut says NO)… Do I need to ‘scan’ every burn? Since I’m new to burning, I’m a little less sure of if this can be eliminated and/or reduced to only scaning every now and then…

So... the bottom line question is... Should I verify and scan? and/or is one more valuable to me then the other, if I should try to eliminate one? Which is more important? Verification bit by bit, or scanning to make sure 'media errors' are not exsessive?

I’m not an expert, but my opinion is that if you want to be absolutely sure of your burnings then you must do both verify and scan

Verify to ensure that data on disc are the same on the harddrive, and scan to see how is the burn and to have an idea on how much time the disc will becose corrupt. In fact, the more are errors on the disc, the little is the time the disc will become unreadable.

In other words, with verify you can check integrity of data, and with scan you can check integrity of the support burned.

If you want more durability, maybe (but I’m not totally sure) RAM media are for you.

Seriously, with high quality CD’s I don’t even verify. I can see doing so if you need to be CERTAIN that the data is there, but I can’t remember the last time I lost data that was on a CD. Maybe some of the stuff I burned with dodgy media like 10 years ago. But nothing since then. Just buy high quality CD’s, and if you need to do a verify do so. I see precious little point in doing a scan on a good quality CD.

DVD’s… are another story. Still something of a black art. In another 5 years… maybe DVD’s will be as ubiquitous and reliable as CD’s. Maybe.

your biggest concern whould be quality discs. once you get a hold of some quality media that your burner agrees with, consistently burns well, and you can trust, then i’d say it’s safe to do away with the verifying and scanning EVERY single disc. maybe do every 5th disc just to be on the safe side.

i think cds have better longevity and even poorly burned cds can be read in low to mid-quality readers for quite some time. i’ve found dvds to be a bit more finnicky, but if you have a good burner, and some good media (not necessarily ty although it’s what i would recommend, but something that you’ve had good experience with and works well with your burner) then I’d say it’s safe to cut out some of the time.

another option that gives you equal portability but at a bit more cost up front would be to just buy an external hard drive. that would decrease your time invested and unless you wanted to view tham on a dvd player (most nowadays can view jpgs) you’d have that with you to plug into any computer that’s nearby.

by the time you invest all the time and all the money on quality media (and we don’t even know what kind of burner you have and whether or not you’ve found it to be reliable) you probably could have just gotten a nice hard drive that will do the job in a significantly quicker amount of time.

like i said, i don’t know if there’s a reason you want to back them up specifically on dvds or if you’re open to the extra drive option, but the drive also gives you the benefit of being able to better organize, categorize, modify, and search through the thousands of photos you have. you’ll always be able to add to the drive, but with teh dvd once it’s burned it’s burned (unless you use RW discs, but that would be a pain to keep reburning discs)

Also keep in mind that that if you make 3 copies of the data and they somehow all go bad there is no reason to believe that the same images would be affected. There is brute force software that reads at a lower level than windows and can read and extract all the good data from a disc even with crc (unreadable sector errors) that would stop normal programs like windows explorer. You could easily rebuild a complete disc from the 3 copies. Locate some of these programs and include a copy on every disc you burn in case you need them later you won’t have far to look. One commercial program is Bad Copy Pro but there are many such programs. Just google “data recovery” or other similar search keys. It will add another layer of security.

Well… a little info about what I have… I have a LG GSA-4081B, and recently aquired a BenQ 1640. I also have some old CD-R burner that I’m not even sure of who made it, I used it years ago on a Mac, and have since retired it (and my Mac).

I’ve scanned some of my CD-R that I made on my Mac, and found that even after nearly 8 years, they are in pretty good shape, and have realtively low error rates.

I got my LG burner a couple years back, knew nothing of scanning or the differance between good or bad media. I guess I got lucky, cause it turns out the Memorex brand DVDs I purchased were RICOHJPN R01, and after doing some scans of the ones I burned two years ago, they appear to be in good shape too. My BenQ and CD/DVD Scan show most to be rated no lower then 95…

I've still got some RICOHJPN R01 media, but it's been on the shelf for at least a year, but seems to burn fine still (I've heard that there is a finite shelf life for unused media, but I'm not positive this is true of false).   I also recently purchased some YUDEN00 T02 media, and have been burning exclusively on my BenQ.  Scans of new and old burns have consistantly been in the 90s on DVD/CD scan.  So, it seems I'm in OK shape at this point...

In many ways I don't want to stop verifying, and know I should probably scan at least every 10 disks or so... (assuming all is good, much more frequently if I ever see problems).  However it's just really tempting to stop doing the 'verify', yet there is this nagging feeling that I should NOT drop that...  Perhaps maybe if I veify one of the two(or more) copies I make that would be enough to sooth the nagging feeling I have that I should verify...

I don’t really want to keep copies of most of these images on hard drive. I know hard drives are realtively cheap these days, but still. I’d estimate that 30 to 50% of the images I take are of very little value, except maybe centimental value. I don’t want to delete images, partly because I see even the bad ones, as sort of a time capsule… where hopefully someday my daughter might want to go back and look at some of the things I thought were worthy of photographing, etc… Now my intention is to keep any really good shots on harddrive, as well as having backups on optical media.

Maybe what I could do is skip the verify of all burned Media, do a verify on at least one copy of each… except in the case where I knew the image was of high quality/value… and I’ll burn addtional copies of only those really good images, and do full verify of those… and keep those good ones on harddrive as well.

Knowing there are programs like ‘Bad Copy Pro’ out there also does also give me some peace of mind that maybe I could drop most of the verifacation, perticularl when
i also know I have multiple copies, etc… Thanks for the info on those types of programs GumShoe… I wasn’t really aware of that sort of thing.

If anyone else has any tips or ideas on this type of thing, keep em comming… I’ll keep reading.

It’s true. With time also unburned media will degrade. To augment at most durability of both burned and not burned media it’s better store all media away from light and in jewel cases, avoiding cakebox.

If you are concerned about security, I suggest you to scan all media that you burn. On a box there can be a bad media (it’s very common to find 1 or 2 bad media on a box). Even if the media is good, can happe something that produce a bad burning, so if you don’t check all media the occasional one bad burned will escape you, and you’ll risk to lose all data on this disc.

Again if you are concerned about security, then you should verify all discs.

Also harddrive can damage, so storing on an harddrive gon’t ensure you to don’t loose data. I suggest you to do multiple backup on optical media of most important images, and store backups away from light and on single jewel boxes.

There is also another software that you can find very useful.

Check here for dvdisaster

I also have about 10,000 photos (although not 80MB a piece) and I have a lot of family video (I don’t know how many hours). For the really important stuff, I have them on cd, DVD, and Harddrive. It might be a pain but if you absolutely cannot lose it it will be worth the effort in the long run.

On the Harddrive, everything is on there twice on different parts of the drive, that way if there is a bad cluster then it will be somewhere else also. If both files on the drive are unreadable then there is dvd and cd backup. Triple redundant backup. Oh, and the harddrive is not kept in the computer. It is stored away from the system in case of fire, tornado, earthquake or even if a hurricane reaches K.C. area. It may sound like overkill but if you absolutely do not want to lose your data then you need to do whatever to make sure you don’t.

Well my unburned media has been in a cakebox/spindle and in a dark closet… temperture is pretty steady at around 70F, maybe when I’m on vacation it might get hotter for a week or so but probably not much above 85…

My burned media of any value gets stored in thin jewel cases, typicaly in the same dark closet as my unburned stuff… however for long term the burned media is most likely to go in my basement, which is realtively dry… probably no more then 60% humidity at it’s worse, and the temp is pretty stable at around 65 degrees year round. I’ll make sure it’s in a dark box to protect from any stray UV.

(I’ve got 8 year old CD-R with home video on it that’s held up really well in my basementl, so I’m reasonably comoforable with this)

I guess for the time being I’ll keep verifying and scanning everything that I hope to read 10 years or more from now… It seems maybe it’s just too risky no to do this. I mean it’s sort of like the old saying… you can pay me now, or you can pay me later… Or an ounce of prevention is worth a pound of cure… or better safe then sorry.

If I could just get myself to burn these things every month or so, rather then waiting till I’ve got like 3000 images that need burned… I spent my whole weekend burning, verifying and scaning about 4000 images… Actualy I probably have some more scanning to do… the burning and verifying is all done.

Oh, I said 8MB a photo… not 80MB… I don’t think I’d be using CD-R at all if I had 80MB size images… I mean you’d only get about 8 images on a CD-R, it’s bad enough to only get 80 to 100 images per CD-R. (I’m saving Canon RAW data from a Digital Rebel, which has a 6MegaPixel sensor…)

Oh, I said 8MB a photo… not 80MB… I don’t think I’d be using CD-R at all if I had 80MB size images… I mean you’d only get about 8 images on a CD-R, it’s bad enough to only get 80 to 100 images per CD-R. (I’m saving Canon RAW data from a Digital Rebel, which has a 6MegaPixel sensor…)[/QUOTE]

Sorry, I mis-remembered what I read. I know photographers that scanned in there photos and only saved in high res uncompressed tif (they would not settle for the tiniest loss of color depth) which can be a minimum of 150 MegaBytes. I’v seen one photo take up a whole cd. I was not that picky.

I also wanted to add that verifying and scanning after you burn is probably not where the process should end.

i’d continue to scan the discs every couple of months or so to track degradation. (maybe only scan one or two to get a respresentation on how they should be doing)

there’s some preliminary data on dvd longevity in the blank media forum here that might be of interest to you.

i’m sure you know this already, but i just wanted to add the extra word of caution that just because a disc scans well now doens’t mean anything 10 years from now. no one knows what’s going to happen 10 years from now since widely avialable technology to copy data to dvds hasn’t been around long enough.

Yes, I intend to do some periodic scanning of disks over time. I also understand there is really know way to know for sure how long the data will remain readable… I actualy assume that sometime in the next 10 years or so, some new technology will come out and I will likely go though a process of coverting all the stuff I have on CD/DVD to what ever new technology replaces it… My sincere hope is that I can get at least 10 years out of a well burned DVD… But Again I’m sort of hedging my bets by burning copies on both DVD and CD… and I will likely burn a second DVD copy soon.

The whole matter of longevity of DVD/CD data is of great interest to me. There seems to be alot of information out there. Some of it seems somewhat ambigious and others I just have a hard time trusting simply because the people who write the information don’t give anything close to scientific… At this point it’s hard to know for sure who to belive on such matters.

Give a try on DVDisaster

see here

I can’t be sure. I haven’t got any burnt CD’s from prior to 1995 to test. My earliest CD’s in 1995… mostly work. Most of them.

All indications are that DVD’s… we just don’t know. Some clearly don’t last nearly as long as CD’s. Some seem to be going strong after a few years. But nobody has more than a 5-year-old DVD to test… and “modern DVD media” (i.e. 4x or 8x mass-produced media) is really only a couple years old now.

I belive I’ve mentioned this ealier, but maybe not… I’ve got about 40 TDK CD-R disks from 1998, I’ve scanned about 25 of them so far, and only one had error rates so high that all the data could not be read. On this one bad disk, the exsessive error was very close to the end… I guess I need to scan the other 15… but so far my CD-R have held up reasonably well…

But then my more recent CD-R media has been made in India… The early scans I’ve don so far on these look fine, but they’ve only been burned less then 2 years…

In 10 years of burning CDs and now DVDs, it NEVER happened to me in normal conditions, when using good media of course, that ‘verify’ fails. It failed only in two occasions:

  1. I accidentally changed the source data while burning
  2. The CD/DVD was defective.

#1 is up to you, #2 can be detected with other tests than verify.

Frankly I think you can skip “verify” when you use good reliable media and you run other tests (more on this later).

Also with good and consistent media, scanning 1 out of 5 discs in the same spindle is largely enough IMO. The rest, I perform a transfert rate test to be sure there is no flaw. Unless you set CDSpeed to perform the test for maximum accuracy (which is useless IMO), a TRT is far less time-consuming than PIE/PIF scans.

Also transfert rate tests can sometimes show a problem with a disc, that a PIE/PIF scan won’t detect.

My routine:

  1. I carefully dust each blank with an antistatic soft cloth (no more ugly solid PIF peaks :cool: ) - and yes, even when it seems “clean”.

  2. I never check “verify” anymore

  3. I scan 1 disc out of 5 burns to check for media consistency (and the 2 first discs of each cakebox)

  4. I perform a TRT on every disc I burn (Nec 3540), at an intermediate setting between speed and accuracy

  5. If the TRT shows any slowdown, I perform it again (can be a glitch)

  6. If a second TRT still shows a slowdown, I mark the disc as suspect, keep it as an alternate backup, and burn another disc with the same data/image. Sometimes if I have some spare time I scan the problematic disc out of curiosity, to learn more about the relation between PIE/PIF/jitter and readability problems.

  7. I inspect all discs under a strong artificial light for possible dark spots indicating dye melting due to impurities or dye defects.

This implies to use a reliable drive for transfert rate test, i.e. one that doesn’t show erratic slowdowns (COUGHbenqCOUGH). NEC drives are the best option I think (for this test, not necessarily as burners).

Of course, for archival purposes, use only Taiyo Yuden or genuine Hitachi-Maxell CDRs, and Taiyo Yuden or MCC DVDrs (CMC DVDRs are interesting for longevity but don’t always burn well on some burners), and keep your discs away from light, dust, humidity and heat.

Hmm… I too have never seen a verify failure on a good disk… about 8 years of burning (but not that frequently)…

TRT… What is it with BenQ and this test? I’m not sure I’ve ever seen a clean 16x transfer test on my BenQ… can you point me to any good threads that discuss this issue?

I do have a LG 4081B and have seen OK TRT tests on that… but it’s max 8X read I think… However at least I have this drive… Are there any known problems with using my LG to do TRTing? (This drive is really not usefull for any of the other DVD/Speed testing since it’s incapable of reporting errors) I just hate to have to buy another burner to do transfer rate testing… ( my wife would kill me anyway )

Sorry, no. :o You’ll have to search a bit. I know my 1640 has unpredictable/erratic glitches in TRT, other users have noticed the same glitches, no review uses a Benq drive for TRT, but I don’t remember any thread dedicated to this subject.

but it’s max 8X read I think… However at least I have this drive… Are there any known problems with using my LG to do TRTing?
Speed, maybe. It’s always better to test at full speed I think, as small imperfections will be detected more easily. At least that’s the way I see it.

TRTing - nice contraction/neologism :bigsmile: - let’s try to spread it :bigsmile:

I use only quality MCC Verbatim DVD and CD discs.
Some of them I store in cakeboxes (family pictures), some of them in clusters (spare copies, apps, my personal backups), and some of them in single jewel cases (games, movies, rarely full albums).
They are either stored in a special device for CD’s which casts shade on them, either in clusters, which, as you know, impregnable from sunlight, or either in cakeboxes, which I keep in a dark shelf.
My room tempature is oftenly hot, however then I turn on the AC, so altogether my room temp is always cool.

  • From now on I will always verify (using Nero). However, what is “Scan” and how do I do it?
  • What’s the shelf life for my backups and in how many years i’ll need to clone them?
  • What’s the shelf life for pressed media’s?

Thanks a lot in advance.

Regards,
muaddib

I’ve never ‘verified’ a disc in my life, at least not intentionally. I do, however, run PI/PIF scans on most of my burns, that and/or transfer rate tests.