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How To Properly Archive Data On Disc Media

Zonk posted about 7 years ago | from the yay-data dept.


An anonymous reader writes "Patrick McFarland, the well-known Free Software Magazine author, goes into great detail on CD/DVD media over at the Ad Terras Per Aspera site. McFarland covers the history of the media, from CDs through recordable DVDs, explaining the various formats and their strengths and drawbacks. The heart of the article is an essay on the DVD-R vs. DVD+R recording standards, leading to McFarland's recommendation for which media he buys for archival storage. Spoiler: it's Taiyo Yuden DVD+R all the way. From the article: 'Unlike pressed CDs/DVDs, burnt CDs/DVDs can eventually fade, due to five things that affect the quality of CD media: sealing method, reflective layer, organic dye makeup, where it was manufactured, and your storage practices (please keep all media out of direct sunlight, in a nice cool dry dark place, in acid-free plastic containers; this will triple the lifetime of any media).'"

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Dupe... (4, Informative)

LighterShadeOfBlack (1011407) | about 7 years ago | (#18559589)

This is practically a word-for-word dupe of a /. posting from December 11th 2006 [slashdot.org]

Re:Dupe... (1)

AbsoluteXyro (1048620) | about 7 years ago | (#18559627)

I thought this looked familiar... It is an excellent article though!

Re:Dupe... (2, Interesting)

LighterShadeOfBlack (1011407) | about 7 years ago | (#18559745)

It is a good article on the pros and cons of DVD-R vs DVD+R in general, however I'm not too happy with the way the author recommends one particular brand over others like that without any hard data to back it up. It's quite possible it's absolutely true and they really are a superior brand of discs, but without presenting any numbers to support his assertion it will remain nohing more than one person's opinion.

Re:Dupe... (2, Interesting)

Dogtanian (588974) | about 7 years ago | (#18560171)

I'm not too happy with the way the author recommends one particular brand over others like that without any hard data to back it up.
To be fair, whilst I'm not claiming that I've never come across criticism of Taiyo Yuden, they seem to be consistently ranked #1 in reliability and quality. In fact, come to think of it I can't recall seeing any reviews where their media (overall) weren't the top rated.

I believe that Verbatim (owned by Mitsubishi) are also very highly rated (except for a brief period in 2002 when they switched to a far less reputable media supplier). More info in this article. [digitalfaq.com]

Bear in mind that a *large* number of major brands don't make their own media; these include companies such as Memorex, Fuji and Emtec (formerly BASF). Apparently you can look at the cakebox/packaging style and media type and figure out if it's good-quality rebranded media inside, but I don't buy enough discs for this to be worth my time; more sensible just to buy from companies that do their own.

Re:Dupe... (1)

Nogami_Saeko (466595) | about 7 years ago | (#18560257)

I'll chime in as well with a statement that I've never had problems using TY media. Of all of the media I've used (and I use a lot - doing commercial DVD authoring), TY is the only one that has never once had a problem.

It's worth noting that this article is specifically talking about data archiving (obviously), where the +R format does offer advantages with error correction/handling. One size doesn't fit all for media however, and I still recommend using DVD-R for video DVD authoring as it has a much higher compatibility with set-top players.


Re:Dupe... (1)

eric76 (679787) | about 7 years ago | (#18560879)

I think the gap between DVD+R and set top players is pretty much decreased to the point that there isn't much difference between DVD-R and DVD+R compatibility with them.

I saw some figures showing the percentage of "modern" DVD players and the difference in the number of models that could handle DVD+R and those that could handle DVD-R but not DVD+R was only something like 2% to 4%.

Re:Dupe... (1)

Master of Transhuman (597628) | about 7 years ago | (#18560547)

It's common knowledge among the CD recording crowd that Taiyo Yuden - a Japanese brand - is the top maker of media. I always buy Fujitsu brand DVDs (although not CDs, because CDs are less critical) because most of their media is made by TY. It's an issue with the proper spreading of the dyes, apparently. The Japanese have the quality control standards that the Taiwanese simply don't have (except in cases where a Taiwanese company is using Japanese equipment and methods, which does occur.)

Check out the forums catering to people who burn music and video on DVDs like cdfreaks.com. A lot of these guys report their success or failure matching particular media with particular drives by measuring the artifacts on burned disks. They have any number of utilities to do this.

Taiyo Yuden comes out on top.

Of course, if your particular drive was never tested with TY by the manufacturer and doesn't happen to like that kind of media, that won't help. The quality of the drive matters, too. I dumped LiteOn after having numerous mechanical and burning problems. I switched to a NEC drive which has performed flawlessly for well over a year now.

Re:Dupe... (1)

DeadChobi (740395) | about 7 years ago | (#18563915)

Meanwhile my LiteOn is still going strong after almost 5 years of use, both as a CD burner and as a regular drive.

Re:Dupe... (0)

Anonymous Coward | about 7 years ago | (#18559645)

Who cares if its a dupe, its still a great article, and maybe some /.'ers missed it :-P

Re:Dupe... (0)

Anonymous Coward | about 7 years ago | (#18559945)

And your point... It's been almost 4 months already!

ATTN: SWITCHEURS! (-1, Offtopic)

Anonymous Coward | about 7 years ago | (#18560147)

If you don't know what Cmd-Shift-1 and Cmd-Shift-2 are for, GTFO.
If you think Firefox is a decent Mac application, GTFO.
If you're still looking for the "maximize" button, GTFO.
If the name "Clarus" means nothing to you, GTFO.

Bandwagon jumpers are not welcome among real Mac users [atspace.com]. Keep your filthy PC fingers to yourself.

Re:Dupe... (1, Funny)

Anonymous Coward | about 7 years ago | (#18561685)

Excellent, thanks. The comments there are much more intelligent.
Oh how I miss 2006, the internet has really gone downhill since then.

Re:Dupe... (1)

RedElf (249078) | about 7 years ago | (#18561831)

This is practically a word-for-word dupe of a /. posting from December 11th 2006

You must be new here...they usually wait less than 4 days to dupe it.

A sticky history (0)

Anonymous Coward | about 7 years ago | (#18559669)

"From the article: 'Unlike pressed CDs/DVDs, burnt CDs/DVDs can eventually fade, due to five things that affect the quality of CD media: sealing method, reflective layer, organic dye makeup, where it was manufactured, and your storage practices (please keep all media out of direct sunlight, in a nice cool dry dark place, in acid-free plastic containers; this will triple the lifetime of any media).'"

Great! Your porn will outlast you.

M*Farland? (4, Interesting)

MDMurphy (208495) | about 7 years ago | (#18559699)

I'm sure it's just a coincidence that we have to articles posted by anonymous readers linking to "famous author" M*Farland, but it struck me as odd. Especially since he commented on the USB story. Could there little astroturfing going on?

It's not like we haven't seen that before ( Roland P* )

Patrick McFarland? (4, Informative)

MysticOne (142751) | about 7 years ago | (#18559703)

I know who he is. I would've never called him a "famous free software writer" as he was labeled earlier today, and if he's "well-known", it's not for being a writer. The way these summaries are worded, as well as the fact that both stories today were submitted by "an anonymous user", just makes me think that somebody is looking to boost their site's traffic today. Nevermind the fact that the article is old and has already been linked to on slashdot before.

Anyway, just seemed fishy to me. That's my $0.02.

Re:Patrick McFarland? (1)

iminplaya (723125) | about 7 years ago | (#18559967)

I never read the articles on Slashdot. That's what Playboy Magazine is for.

Check your calendar (0)

Anonymous Coward | about 7 years ago | (#18560705)

My theory is that it's an April Fools joke one day early. I mean, calling him "famous" and "well-known" has got to be a joke, right?

Mods, can I get an Insightful, Interesting, or Informative here? :)

Re:Patrick McFarland? (0)

Anonymous Coward | about 7 years ago | (#18560837)

I think Patrick must be dating the slashdot editors, as he gets quite a few articles posted, all trading on his Free Software Magazine credentials. (Where he hasn't posted in quite a while, after posting a handful of entries last year.)

Re:Patrick McFarland? (2, Informative)

diablo-d3 (175104) | about 7 years ago | (#18563377)

Don't look at me. Whoever this anonymous coward is, he/she must have a sense of humor. I've written for Free Software Magazine three times I think, and one of those even made it to Slashdot. As much as it rocks to be linked to Slashdot twice in one day, I do not, and have never, described myself as some famous author, nor as as a famous coder, nor as any of the other things I've seen.

Rule #1 (0)

Anonymous Coward | about 7 years ago | (#18559733)

Don't archive with anything made from protons, as it is theorized that they decay even when stored in a cool, dry vacuum.

Why bother with optical? (3, Interesting)

Anonymous Coward | about 7 years ago | (#18559895)

A 500GB hard drive is like $150 these days and 1TB drives are just around the corner. Drop one into a $10 USB enclosure and backup your stuff using rsync. To do it right, do this twice with 2 different drives and store them in 2 different physical locations. I don't care what fancy pants brand of DVD-R you use, a magnetic solution is still superior in both durability and simplicity (try backing up 100GB of data using a DVD writer and a hard drive, then tell me which one took longer).

Re:Why bother with optical? (1)

TheSHAD0W (258774) | about 7 years ago | (#18560087)

I agree, and it's faster to archive and restore. You'll want to store it in a cool, dry place, in an environment that's as static-free as possible.

Re:Why bother with optical? (1)

Lucky77 (777803) | about 7 years ago | (#18560223)

Just about 10 years ago $150 is what a 500 MB Maxtor drive would cost. Having the much denser drives now changes the criteria concerning backup and archival methods. DVD's, regardless of being -R or +R, still seem flaky to me. Perhaps as the technology matures (increased reliability) along with a magnitude increase of density then I will take another look at utilizing DVD technology for archiving.

I just bought two 500 GB drives ($139 each) last night for the very same backup strategy that you suggest. I plan to keep one offsite and the other in my library in a large book size box that looks like a book, but is designed for holding whatever booty one desires to put into it.


Re:Why bother with optical? (2, Informative)

Hatta (162192) | about 7 years ago | (#18560301)

At $150 a 500gb drive is $.30/GB. At american-digital.com (my personal favorite place for bulk media), I can get 16x Taiyo Yuden dvd+r media for about $.60/disc; which, at 4.7GB/disc, works out to $.128/GB. So hard drives are more than twice as expensive per gigabyte as DVD+R.

Re:Why bother with optical? (5, Insightful)

Anonymous Coward | about 7 years ago | (#18560595)

I think you're really making their point. Optical media just isn't cheap enough to bother with it anymore, and with the prices of magnetic storage always decreasing, there's even less of a reason to use optical media.

Yes, you'd save a few bucks initially by using optical media. But then you have to split all your data in evenly sized 4.7GB archives or such. Label them all manually. Waste hours swapping hundreds of discs by hand. Catalog all these discs (number them, keep a database or something0. And they take LOTS of physical place to store.

I got tired of looking for a specific DVD. After an hour of flipping thru pages of those (expensive and large) CD wallets and not finding it, I gave in, and bought several TB worth of HD space. Now if I want a movie, it's there, listed alphabetically and all. Jewel cases suck too -- too brittle, wastes space too, and a waste of money.

HDs have a very high density (the new 1TB drives will store more than a spindle of 200 DVDs), requires no storage cases, no constant media swapping, no splitting to fit the size of media, etc. It's all-around better! Restoring stuff is almost instantaneous. You never have to look for a specific disc. Transfer speeds are great. Everything is sorted alphabetically inside folders/directories... What more could you ask for?

Want to make a new copy - to another format, or just onto newer media? It takes what, 15 seconds to start a copy job using HDs? With optical media, you'll be swapping discs by hand for months.

Plus, HDs are not read only -- you can make monthly backups on them no problem (full or differential). Using optical media this is a pain. The cheap discs are write-once, and even if the rewritable discs were cheap, it still takes a while to erase them all manually.

Backup/sync jobs can be totally automated using HDs. Want to do daily differential backups? Schedule it once, never have to bother ever again. With optical discs you'd be swapping, labeling and cataloging media 365 days a year... What a pain.

Long story short, I might as well backup all my storage on 1.44MB floppies instead of optical discs. It'll take hundreds or thousands of them, and you'll spend countless hours swapping media and splitting stuff to fit the media size. NO THANKS!

Re:Why bother with optical? (1)

Lucky77 (777803) | about 7 years ago | (#18560783)

Please mod this AC up

Re:Why bother with optical? (1)

aurispector (530273) | about 7 years ago | (#18562331)

Yup, the simplest, fastest and most reliable method of backing up data is a portable USB drive. Dunno about the cost but if they aren't cheaper now they will be soon. The author of the article shills for DVD+R quite effectively but how long will it be the standard? What's new? Blu ray?

HDDs keep getting cheaper in terms of dollars per byte stored. They are also getting faster, smaller and more reliable. Why bother with anything else?

Reality Check (0)

Anonymous Coward | about 7 years ago | (#18563033)

External HDD: 1000GB for $298 [newegg.com] = $0.298/GB
Internal HDD: 320GB for $80 [newegg.com] = $0.25/GB
DVD+R: 470GB for $26 [newegg.com] = $0.055/GB

It's also a lot easier to lend someone else a DVD than a hard drive, even external ones. Especially if your data really is naturally divisible into smallish chunks.

Re:Reality Check (1, Insightful)

Anonymous Coward | about 7 years ago | (#18563379)

External HDD: 1000GB for $298 = $0.298/GB
Internal HDD: 320GB for $80 = $0.25/GB
DVD+R: 470GB for $26 = $0.055/GB

It's also a lot easier to lend someone else a DVD than a hard drive, even external ones. Especially if your data really is naturally divisible into smallish chunks.

Oh, so your time spent burning DVDs is worth nothing eh? Let me give you a call sometime so you can back all my shit up for free.
I have a cron job that executes at 4am that copies everything to a USB external hard disk. I think it took about 30 seconds to write the script.

But how reliable are HDDs? (2, Interesting)

AmiMoJo (196126) | about 7 years ago | (#18566111)

I ask myself this a lot: how reliable are HDDs in the long term?

Say you use them for archiving. It is better to go the NAS route and have them always on, or powered down when not in use? How about a USB enclosure only connected when in use? How reliable is an almost-new used-it-once HDD that has been sitting on a shelf for five years?

Re:Why bother with optical? (2, Interesting)

Master of Transhuman (597628) | about 7 years ago | (#18560625)

What's your time worth? As someone said, backing up 100GB of data - something I do periodically and I do it on DVD - takes time. I back up over 200GB of data off my machine to DVD - it takes me most of a day of personal attention. Backing that up to an external hard drive would take much less time and require nothing more than starting the transfer (depending on how the files are being selected of course).

That said, DVD (or tape, of course) is better for offsite archival storage than disk in many, if not all, cases. But nothing can beat disk for fast, local, immediately available backup.

And disks are getting cheaper and with more capacity all the time. While tape is approximately matching disk capacity - and even speed if you buy high-end units - tape drives that can handle that capacity and speed are way more expensive than disks.

It's a no-brainer. The only reason I haven't switched yet to disk backup for everything is that I can't right now afford to buy the drives vs buying 50 DVDs at a time. Plus I'm waiting to upgrade to a whole new machine, at which point I'll move the current machine to act as a file server and attach an external USB or NAS drive system as a backup. This will give me three tiers of backup - the workstation, the file server, and an external backup. Then I can still periodically burn to DVD for offsite storage if I want to.

Re:Why bother with optical? (2, Interesting)

KokorHekkus (986906) | about 7 years ago | (#18560663)

And add to this that failure of one optical disc is less catastrophic. If one optical disc fails you have a lot less loss than if one drive does... of course that means more work but there is always a trade-off, isn't there. You could argue that you should have more than one drive but the same goes for optical disc.

From personal experience optical discs might need one more step though: to verify that the write was ok. I don't have any optical discs that have failed me yet after I started to check writes... turns out the only problem was that I had a writer that was about to give up. Hence not a read error but a write one... after that I always run a check.

And a anecodotal story against those who says that it will "allways fail in N months". A swedish tv program took some burned DVDs, put them in a plastic bag and chucked them outside under a bush for about 3 months no problem reading them. So with optical media: check your write + store them as proper archieval media should be.

Re:Why bother with optical? (0)

Anonymous Coward | about 7 years ago | (#18562141)

add to this that failure of one optical disc is less catastrophic
But it's far more common. From scratches, to the metal backing that peels off, oxidization, defects in the plastic and all that... Who hasn't seen bad discs? Go rent a DVD anywhere, and you'll see why handling media directly is bad. I've seen thousands of bad discs, yet only a handful of bad HDs (providing yours aren't ancient, a lemon like the IBM deathstars and properly cooled they shouldn't crash anytime soon)

You could argue that you should have more than one drive but the same goes for optical disc
Difference being, I actually HAVE more than one copy on a hard drive - at least of the really important stuff. Why? Because it took mere seconds to make it happen (simple everyday file copy operation). Were I to make 2nd copies of DVDs, I'd be swapping, lebelling, cataloging, filing discs for weeks. One takes seconds (and often an old HD you weren't using anymore could suffice), while the other is so much of a PITA you'll never actually do it, making hard drives a safer option overall.

I've given up on optical media when I had to start recopying old CDs (with movies in mpeg4 mostly) onto something newer. It took me MONTHS to recopy it all onto large hard drives. If I was then re-writing this to more optical media (DVDs), I just might be still working on it, and I know I'd have to go thru this all over again in a couple years or so. BTW, I've lost many, many discs. Most were reputable name brand, properly stored and all. 3 months is nothing. Try recopying a couple thousand 5yo+ CDs and try telling me none were bad with a straight face... Oh, as a bonus, all my movies are instantly accessible over the network -- no more looking for the F#@$%$#$ disc anymore, and no more shelves full of ugly CD wallets.

Re:Why bother with optical? (0)

Anonymous Coward | about 7 years ago | (#18562251)

But it's far more common. From scratches, to the metal backing that peels off, oxidization, defects in the plastic and all that... Who hasn't seen bad discs? Go rent a DVD anywhere, and you'll see why handling media directly is bad Last words from the parent above you: "...store them as proper archival media should be." You think DVD rentals is proper storage? You gotta be kidding.

Re:Why bother with optical? (1)

zoftie (195518) | about 7 years ago | (#18561431)

Perhaps you'd like to calculate the time, that it takes for you to swap in and out and keep track of the media. Unless you have some automated solution to make backups on multiple cds with robot arm actuators replacing dvdr's and marking them, with likes of inkjet.

Nope, I'm with the germans on this one... (0)

Anonymous Coward | about 7 years ago | (#18561645)

... Yuden raus!

Re:Why bother with optical? (1)

shoor (33382) | about 7 years ago | (#18560555)

I've thought about doing that, but, what bothers me is that if the hard drive fails, it could take out ALL the
data on it. (Granted, there may be ways to recover some or most of the data, unless the drive is just utterly
destroyed in a fire or something, and if it was a fire, your whole box of DVDs would probably be wiped out
too). Also, with DVDs or CDs, one buys incrementally to archive; one could put
some money in an interest bearing account for instance, though it's a trivial amount. Finally, there's a
psychological factor for some of us: It's not archived if the media it's on can be erased and re-used.

Re:Why bother with optical? (0)

Anonymous Coward | about 7 years ago | (#18563357)

That's why I said "do it twice" and store them in different locations. Hell, in the time it takes you to do 1 100GB backup to DVD's, I can make 5 hard drive copies and still have time to jerk off.

Re:Why bother with optical? (4, Insightful)

pogopogo (464296) | about 7 years ago | (#18560667)

There is a difference between an archive and a backup.

An archive is something that is stored in a safe location for possible use later, but also to save for posterity.

A backup is used to keep current data in two locations in case one set of data is lost.

Hard drives are fine for backups. For archives you want write-once media that can't be easily (or even possibly) erased.

Two different solutions to two different problems.

Re:Why bother with optical? (2, Funny)

MMC Monster (602931) | about 7 years ago | (#18561097)

This article is not a dupe. It is simply a backup of the /. article of December 11, 2006.

Re:Why bother with optical? (3, Interesting)

MMC Monster (602931) | about 7 years ago | (#18561171)

On topic: People should use something like par2 to create some fault tolerance so that when a few bytes go bad (or a scratch develops) the entire DVD+/-R is not toast.

I typically create data DVDs with 30% redundancy information (though smaller percentages are probably more than adequate) with par2create, and store those par2 files on the same DVD. That way I survive the little scratches and can recreate the data.

Isn't there already some redundancy? (1)

Kadin2048 (468275) | about 7 years ago | (#18563975)

Doesn't the ISO9660 format already have a certain amount of redundancy in it?

Not saying that using PAR2 to create some additional redundancy is a bad idea, but I don't think that one-bit errors are totally disastrous automatically, if you've burned your data in a normal format.

Not sure what UDF does, though.

Although it's not as if PAR2 is a particularly exotic format, just in case it drops out of common use in the future, I think I'd still put a plaintext copy of the source code for the reassembler on every backup volume, or at least on the first volume in each set, just to make life potentially easier down the road. (And even if the format doesn't drop out of use, having the backups be self-contained in terms of containing the software necessary to decompress/assemble themselves would let someone use them even if they didn't have network access, which might be handy.)

Re:Why bother with optical? (0)

Anonymous Coward | about 7 years ago | (#18566091)

Hard drives are fine for backups. For archives you want write-once media that can't be easily (or even possibly) erased.

By your definition, magnetic tapes were never archive media. Paper printouts it is, then! Can I get you a punch card with that?

Get a clue. Hard drives are excellent archive media. Hot swappable. Put them in a closet or safe. Very insensitive to light and heat. Blazingly fast (so you're more likely to *create* archives in the first place.)

Optical doesn't get fried by power surges. (1)

AJWM (19027) | about 7 years ago | (#18560885)

I've had hard drives fried by failing power supplies. Sometimes you get lucky and replacing the electronics from an identical drive works, sometimes it doesn't. I've never heard of a CD or DVD drive's laser suddenly burning holes in the disc.

Ditto with mechanical shock -- a DVD will survive a lot rougher handling than a harddrive will, even if the latter's heads are parked.

There are always trade-offs.

Re:Optical doesn't get fried by power surges. (1)

tomhudson (43916) | about 7 years ago | (#18561701)

" I've never heard of a CD or DVD drive's laser suddenly burning holes in the disc.

I've had cd drives that ate the cd, and one time ejected a cd at high speed. Think frisbee, not coaster. When a disk fails at 52x, your PC will sound like an unbalanced washig machine.

Ditto with mechanical shock -- a DVD will survive a lot rougher handling than a harddrive will, even if the latter's heads are parked.

Drive over a hard drive, then put it back in the machine - it'll work. Just drop your 100-spindle stack of dvds on the floor (because they were way more awkward to handle than one stupid hard drive) and at least one will land on its edge and develop fractures - not to mention the scratches and the way that any ambient dirt will get on them.

Your time has to be worth something - dvds just aren't worth the time any more, and usb keys are getting so cheap (and large enough) that for many purposes, back it up to a key and throw it in a drawer off-site.

Re:Optical doesn't get fried by power surges. (0)

Anonymous Coward | about 7 years ago | (#18565909)

>I've never heard of a CD or DVD drive's laser suddenly burning holes in the disc.

I've had it happen!

Re:Why bother with optical? (1)

TonyTech (1031316) | about 7 years ago | (#18562899)

Try this: backup your data to an external hard drive. Then, shake it violently over your head a few times or drop it to the floor from 4 feet. Then try and read your data from the drive. I don't trust mechanical magnetic drives for backup as far as I can throw them!

Which leads to... (3, Insightful)

BlurredOne (813043) | about 7 years ago | (#18559903)

This just brings up the question:

Is there a point to digitizing human cultural pieces that has survived for 10,000 years onto media that will fail in 10?

Re:Which leads to... (1)

Surye (580125) | about 7 years ago | (#18560123)

That's the benefit of digital, it doesn't degrade over copies, so each generation of storage media gets a perfect copy from the last.

Re:Which leads to... (2, Insightful)

the eric conspiracy (20178) | about 7 years ago | (#18560281)

That's the benefit of digital, it doesn't degrade over copies, so each generation of storage media gets a perfect copy from the last.

That is certainly not true, and even worse digital is less resiliant to errors than analog formats.

Re:Which leads to... (1)

Kjella (173770) | about 7 years ago | (#18565385)

"That's the benefit of digital, it doesn't degrade over copies, so each generation of storage media gets a perfect copy from the last."

That is certainly not true, and even worse digital is less resiliant to errors than analog formats.

If there are errors, I don't recall them ever happening in the copying, they happen in storage. And while single bit errors can happen, with checksums I can verify that I have files that are closing in on 20 years old that are perfectly preserved. With PAR files I could even recover them too. No, more often than not the media itself is shot, for example you get CRC errors from the DVD or the disk dies. Then it's just about having another good copy. i guess it all depends on how big an issue it is, a bit error in a financial statement might be a big issue, if it's one wedding picture where you in the digital day and age take five others of the same subject plus hundreds more for the rest, then honestly it isn't.

I'd say that if you can manage to preserve all your files (i.e. nothing lost due to known broken media) then you're past the 99th percentile. That is not so easy as it sounds, you need backup, depending on the disaster (e.g. fire) maybe offsite, you need to have restore tests and you need to cycle your media. And if that's not enough, you can make it even more resiliant.

Yes, if I got the choice between a single digital copy and a single analogy copy I'd take the analog copy any day. But if I can add some PAR, encrypt (for privacy) and uplaod it to my parents' machine for offsite backup, I've got analog so far beat in resiliance it's not even a competition. Uploading a few hundred MB of pics when 700MB divx rips have been going round forever is honestly not a big issue anymore.

Re:Which leads to... (1)

BlurredOne (813043) | about 7 years ago | (#18560297)

Very true. And I dont dispute the merits of digital.

However.... There are plety of cultural pieces that have survived in harsh environements, wars, etc. and are still in relatively good condition. Put a cd outside for 1 year and its fubar. Thats the point I was trying to bring across.

We may be able to make perfect copies indefinetly, but at some point in the future, someone, somewhere, will have the great idea of digitizing art, and destroying the original, then leave the only copy of Mona Lisa out on their desk in the sunlight, and it will be lost forever.

Re:Which leads to... (1)

Lucky77 (777803) | about 7 years ago | (#18560299)

Good Point. One needs to keep the old stuff updated into current technologies though. I know of individuals that have information stored on reel to reel tapes that have little possibility of ever being copied to current media leave alone being reformated into a usable format.


Re:Which leads to... (1)

blubadger (988507) | about 7 years ago | (#18560393)

Or, if you want to do away with the "generations" altogether, engrave the digital data into a rock — with suitable instructions on how to decode, of course. That way your data becomes immortal, more or less. On the other hand, you would probably need a mountain-sized rock for the average TIFF.

Re:Which leads to... (1)

LighterShadeOfBlack (1011407) | about 7 years ago | (#18560327)

It also brings up a partial answer: Not using consumer-oriented optical discs.

A more complete anwer to your question: Yes, it is worth it. Existing peices of history may have "survived" thousands of years, however I'm not aware of anything that has survived that time completely intact. And despite all the modern preservative techniques at our disposal we still cannot completely prevent the degradation of physical artifacts. Digitised content on the other hand can be copied infinitely and perfectly preserved indefinitely with the proper techniques and the relevant care taken. Of course those proper techniques require something more sophisticated than a DVD writer, but I don't think anyone seriously thought otherwise did they?

Re:Which leads to... (1)

BlurredOne (813043) | about 7 years ago | (#18560541)

It's not that I don't see the merits of digitizing for preservation. My issue is with the belief that digitization is the only answer to preservation. I rue the day that we no longer work at preserving our original pieces just because they are stored 'perfectly' in a digital format.

Formats will change, but paper will always be paper. Marble will always be marble. And art (in all its forms) will always be art.

Re:Which leads to... (1)

HairyCanary (688865) | about 7 years ago | (#18563569)

I think perhaps you miss the point. Storing something digitally is not something you do because a single digital copy is somehow better than a single analog one. You do it because you can make an arbitrarily a large number of duplicate copies of the data and therefore keep it safer than a single analog one could ever be. Don't just have it at the Smithsonian... have a million perfect digital representations all over the world.

Re:Which leads to... (1)

Kadin2048 (468275) | about 7 years ago | (#18564219)

I don't think it has to be an either-or decision.

If an artifact has existed for 10,000 years, only a fool would suggest that we destroy it and only retain copies that are on an untested medium. However, if some new medium makes the data more convenient and useful, then there's no downside, really, to making it available in both -- keeping the old format and also copying it into a modern electronic one.

Just as a trivial personal example, I have a lot of photographic slides and negatives. Some of them (the ones taken by people in my family who knew, at the time, that they were taking photos of something historically or personally significant) were shot on silver halide black-and-white, or Kodachrome color film. They'll probably last a century or more, properly stored. Short of glass plates, they're the modern photographic equivalent of stone tablets. But I've still scanned them in, not so much for preservation purposes (although there is that -- what if the house they're stored in burned down?) but for convenience. The originals will still hopefully always be around, but it doesn't make any sense to only keep them in a format that's increasingly hard to use and enjoy. A whole lot of people have gotten to see them since I've put them up on Flickr, then ever would have seen them just as 2x2" slides.

I think this approach ought to be the ideal model for things like important records; paper (at least, good cotton paper) has pretty amazing longevity. But it's really inconvenient to work with -- digital records are superior from an accessibility standpoint in almost every way. But it's dangerous to not keep physical copies, because most digital storage formats just don't have a very long track record. We can make guesses that some media will last a hundred years, but really, who knows? Unfortunately, from a budgetary standpoint it's the most expensive solution, but for Things That Matter (whether on an individual, organizational/corporate, or governmental/cultural level), it's almost unquestionably the way to go if at all possible.

Re:Which leads to... (1)

alphamugwump (918799) | about 7 years ago | (#18564795)

Yes. "Preserving" stuff (artifacts or information) isn't really just about chucking a bunch of junk in a clean, dry place. To be useful, it must be accessible.

Remember "Raiders of The Lost Ark"? How at the end, some old guy hides the Ark in a government warehouse? You might write your important cultural stuff in stone, but if nobody can find it, it might as well not exist. Another example: the beard of the Sphynx is sitting in a back room somewhere in the British Museum. But nobody knows it's there, so who cares?

Basically, if information isn't easy to get at, it's effectively useless. You might have some very important data stored on one of a thousand CDs, but it's effectively useless. On the other hand, if it was stored on a hard drive somewhere, you might be able to find it. Likewise, there might be some important stuff sitting in a museum somewhere, but if people can't see it, what's the point? If it was online, again, it would be more useful.

Another thing: have you ever tried to find information about things that happened before 1993? For example, NPR has online archives of their shows, but they only go back so far. I'm sure there's a basement somewhere full of analog tapes, but that doesn't do me any good, and again, it might as well not exist. Ultimately, I think that any history that isn't digitized, thrown on the internet, and mirrored, is going to vanish. That's right. When those superintelligent robots look back, 2000 AD is going to be like the beginning of written history.

Besides, the really important information isn't written in stone. Culture can't be "preserved", only kept current. Before we had writing, we had the oral tradition. We stored information through stories. We kept the interesting stuff, and threw away the rest. Admittedly, this method has a good deal of corruption, but it does work: there are stories about Odysseus all the way from Scotland to Iran. Likewise, we still sort of understand the bible after 2000 years, and we're probably going to keep it around for a good bit longer.

But the cultures that don't write anything down, and that nobody gives a shit about anyway, they just get forgotten.

DVD-RAM best for archiving (0)

Anonymous Coward | about 7 years ago | (#18560105)

For achival DVD-RAMs are best suited, because they are purely chemical and supposed to last up to 30 years. It's a little slower to write than DVD+RW, but data correction and verification is way better. The UFS filesystem also retains most Unix/Linux file attributes. And while a DVD-RAM is a little more expensive, you generally only need a few of them for home backups. (Besides the obvious reuse advantage.)

Disks BAH! (2, Funny)

iminplaya (723125) | about 7 years ago | (#18560139)

I prefer cylinders [tinfoil.com]. If they were good enough for grandpa, they're good enough for me.

Note: With I can gather from the name of the site, it appears they might also sell hats, but I couldn't find a link.

Dude - you need to update! (1)

NotQuiteReal (608241) | about 7 years ago | (#18561901)

Those cylinders are analog. Don't be such a square. You need to get digital, man, that's where it's at.

Check this out for all the tactile comfort of cylinders, with the convenience of digital - paper tape [baudot.net] is where it is at!

Redundant Archive of Inexpensive Discs (1)

Doc Ruby (173196) | about 7 years ago | (#18560253)

And since the optical media is so cheap, make multiple copies of each disc, with data shuffled around on the surface on each copy.

That way, any "spot defects" will be very unlikely to hit the same data on every copy. Making the whole redundant backup set last many times longer.

Re:Redundant Archive of Inexpensive Discs (1)

Lordpidey (942444) | about 7 years ago | (#18560465)

Uhh... I seem to recall that CDs have enough spots on the disk to hold like 1.8gb of data, but there needs to be heavy redundancy, and thus only 650mb can be used.

Re:Redundant Archive of Inexpensive Discs (1)

Doc Ruby (173196) | about 7 years ago | (#18561665)

There is no redundancy like that. Or else you'd already see "1.8GB: use at your own risk" discs. Or CDs that are a lot more loss resistant than they are now. Or at least a mention in the article we're discussing of this triple redundancy.

Re:Redundant Archive of Inexpensive Discs (1)

AusIV (950840) | about 7 years ago | (#18562451)

From Wikipedia [wikipedia.org]:

CD-ROM Mode 1, usually used for computer data, divides the 2352 byte data area defined by the Red Book standards into 12 bytes of synchronisation information, 4 bytes of header data, 2048 bytes of user data and 288 bytes of error correction and detection codes. These codes help prevent the data from becoming corrupted, which could lead to errors for executable data.

This means on a 700 MB CD, you have ~840MB of space. Audio CDs use this extra space because data corruption isn't too significant (just a blip in the audio), but with data CDs you'd rarely get a successful CD without any redundancy.

So 1.8 GB? Not a chance. But there is some redundance.

Re:Redundant Archive of Inexpensive Discs (1)

Doc Ruby (173196) | about 7 years ago | (#18563083)

Well yes, there is a filesystem, ISO9660, which eats some data as overhead. And the 288 bytes error correction/detection. But that's not data redundancy, it's really detection, not correction. For correction it would have to have 1168 bytes of correction for 1168 bytes of data.

And you can't use the "extra" bytes above 2048 per frame for data, because you need the filesystem to do what it does. If you encoded in CDDA, which is no filesystem/overhead, you start losing data immediately on different players than the one that originally recorded it, and probably even with the original. It's not really redundancy if you can't do without it.

Good experience with DVD-Rs myself (3, Informative)

bouis (198138) | about 7 years ago | (#18560467)

A quick primer: you can "error scan" DVD+/-R media with a drive that supports it. CDSpeed, a [free, IIRC] utility distributed by/with Nero, can easily save these scans. DVD enthusiasts often compare their scans... cdfreaks.com is a great discussion site.

Some media have been observed to degrade fairly rapidly, others are quite stable. About a year ago, and again recently, I scanned a number of relatively old DVD-R discs [backups, uh, owned by a friend] burned from fall of 2002 on. You can see my post here:

http://club.cdfreaks.com/showpost.php?p=1733269&po stcount=294 [cdfreaks.com]

Funny thing is that most of the discs I used were of a brand widely lambasted as "cheap ____" and I was told that they wouldn't last six months. Curiously enough you can see that the cheaper "Princo" media has held up better than the "gold standard of the day" Riteks [although both are much better than some]. You can also see that one of older discs was scanned recently, and more than a year ago. It shows almost no degradation during that time [and what it does could easily be attributed to the aging scanning drive].

The CDFreaks forum has a lot more scans, including of older media. If you've got some discs and are worried about their aging stability, here's a good place to start:

http://club.cdfreaks.com/forumdisplay.php?f=33 [cdfreaks.com]

good old days (1)

scottnews (237707) | about 7 years ago | (#18560903)

I started burning CDs when a burner was $500.00 and only available as a SCSI drive. This is one rare times I'm glad I was on the bleeding edge. Back then you had to know what gold/gold , blue/gold , blue/blue. Was it made in Japan or Taiwan. Turn your screen saver off. Buffer under run protection did not exist. A 4x burner was fast.

Now people complain if you can't burn faster than 24x. Ask them what color their media was and you'll get something like, "Its magenta with Sony written across it." People just don't learn the basics anymore.

If you burn and it fails in a few years, then you need to: gold/gold has the longest lifetime, silver/silver is the most compatible, made in Japan, keep it out of sunlight, burn at 8x or less if you really want it to last.

the whole premise os wrong (1)

Alien Being (18488) | about 7 years ago | (#18560975)

A friend and a very competent sysadmin said to me (maybe 5 years ago) "tape sucks".

He told me in many ways, why any kind of disk archive was better than tape. I've thought about that conversation many times.

My conclusion FWIW, is the same as everyone knew half a century ago. Accessibility-density-longevity... pick = two.

Re:the whole premise os wrong (0)

Anonymous Coward | about 7 years ago | (#18561865)

that argument would seem to favor tape

Fails to mention MO (2, Informative)

zoftie (195518) | about 7 years ago | (#18561179)

Magneto-Optical media is used by medical facilities where archival time length is paramount. Such as:
  - http://md5.ca/~pavel/md.jpg [md5.ca]
  - http://tinyurl.com/2cu7zv [tinyurl.com]
MO drives are a bit costly, but if you have important media its worth it. Besides cool look for neo's warez stash in Simulcara book. Quoted guaranteed archival time is over 40 years in most cases, and they continually improving the technology, compared to driving the costs down of the generic blank media market of CDs/DVDs.

Re:Fails to mention MO (1)

tomhudson (43916) | about 7 years ago | (#18561873)

"Magneto-Optical media is used by medical facilities where archival time length is paramount."

My last magnto-optical media died from the click of death, you ignorant clod.

Re:Fails to mention MO (1)

DjRenigade (1079881) | about 7 years ago | (#18564809)

The format is a no go. Way to go Sony, once again!! In the begining, i loved Minidisk players and i still own a Mrz-30 that still works well. I have a Net-Md and it sucks!. I see where i work they have 3.5 MO disks. you can only order them from Japan or somewhere like that. It is a shame that they never caught on. they have very good sound quality, 20-20k. The ATRAC3 format would even hold up to 5 hours of music compressed. The interface was the problem. Oh well, back to work...

Other tips: (2, Funny)

pizzach (1011925) | about 7 years ago | (#18561265)

Other tips for longativity:

- Use acid free CD-markers when marking
- Do not use as a coaster like your America Online CDs
- Do not play Frisbee outside with your CDs (Exposes to direct sunlight)
- Chewing reduces durability

Obsolete conculsions (1)

Cafe Alpha (891670) | about 7 years ago | (#18561877)

The article admits that Taiyo Yuden's formulation used to be the best, until they improved all of the others!

We're to use Taiyo Yuden's "Super Cyanine" "stabilized" Cyanine dye, because for a short time, it was the best dye. But then the article goes on to admit that TDK' "metal-stabilized Cyanine" is rated for the same shelf life. Then it goes on to admit that the "Metal Azo dye" I see listed on the brands I've been buying is rated for a longer shelf life than either of the previously mentioned ones, but then claims it's not better. OK, but you didn't claim it was worse either!

So basically, this guy took an obselete article that said that some obscure brand makes longer lasting DVDs, and as the other major companies have caught up or even exceeded Taiyo Yuden for longevity, he did not rewrite the conclusion.

I challenge anyone to find any support in that article for it's conclusion. What's the reason for prefering Taiyo Yuden over Mitsubishi? I don't see one! Over TDK? I don't see one.

And, I believe that I'm seeing the Mitsubishi formulation sold by Sony.

I wonder if choosing longer lasting dyes is the reason that I'm seeing 2x speed Verbatim double layer disks instead of the 8x double layer disks I used to buy?

DVD-RAM would be the way to go if 12x media (1)

TonyTech (1031316) | about 7 years ago | (#18562969)

... was available other than in Japan. I think there is an importer of 12X media now though. Though DVD-RAM can't be used in regulated environments that specify true WORM media, for other (small, SOHO) data backup chores, it would be the thing to have (with 12X media). NewEgg has 12X DVD-RAM drives for under $40. Personally, I think they are purposely keeping DVD-RAM media away so as not to suppress Blu Ray adoption. Wikipedia has a pretty good writeup on DVD-RAM. The history of optical media for computer data storage is indeed a fiasco. A severe lack of leadership by the industry IMO.

DVD Writable sucks badly as archival technology. (3, Interesting)

gweihir (88907) | about 7 years ago | (#18563271)

Sorry, but if you have to select media and burner based on some black magic, then the technology is entirely unfit to be used for any archiving. Archival media give you ensurances like 30 years data lifetime in any combination. You can already get that with MOD. MODs have >50 years data lifetime and drive makers will allways support the lasdt three media generations (currently they are supporting all, i.e. the last fife generations and that wor reading and writing). The only DVD technology that is somewhat comparable is DVD-RAM with cartridge. But that seems to have zero market share in the computer business.

My conclusion is that either people do not care about their archived data or that the number of, e.g., lost baby- and wedding-photographs is not high enough yet.

Re:DVD Writable sucks badly as archival technology (1)

tonywestonuk (261622) | about 7 years ago | (#18564089)

What a MOD?..... Link Please!

Re:DVD Writable sucks badly as archival technology (2, Informative)

FateStayNight (1000465) | about 7 years ago | (#18564343)

Magneto Optical Disc Probably the cheapest comsumer priced devices are Sonys HIMD which are pc compatible, although even these are getting hard to find too. People dont like good technology it seems.

Just use a hard drive (1)

jspenguin1 (883588) | about 7 years ago | (#18563841)

Here [wiebetech.com] is an excellent article on the true cost of archiving to CD/DVD. I have grown to distrust optical media more and more. The only CDs I burn now are KNOPPIX discs, OS install discs, etc. Anything important I archive to a hard drive. I have an external SATA enclosure that has a removable tray.
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