How To Choose Archival CD/DVD Media 225
An anonymous reader tips us to an article by Patrick McFarland, the well-known Free Software Magazine author, going into great detail on CD/DVD media. McFarland covers the history of these 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)."
I agree... But where can I find some? (Score:3, Informative)
The only drawback is that you can only order them from the Internet. I do not know of any retail store who actually sells the brand outright nor do I know of any brand (like Sony, Memorex, Fujifilm) who sells rebranded Taiyo Yuden discs.
Also, the Taiyo brand is more expensive than any other brand.
Re:He forgot the most important one... (Score:4, Informative)
Patrick got his bits wrong... (Score:2, Informative)
Re:I agree... But where can I find some? (Score:5, Informative)
Re:Price is all that matters in the short run (Score:3, Informative)
Takes way, way longer to burn a DVD that way, but it's worth it.
MediaSupply.com (Score:3, Informative)
The secret to spotting Taiyo Yudens (Score:5, Informative)
I've seen Taiyo Yuden CD-Rs and DVD+/-Rs in a number of retail stores under various brand names. I'm hesitant to publicize my trick, but I suppose the Slashdot community should know. Here's how to spot Taiyo Yudens quickly in the store, without checking each label for "Made in Japan":
The spindles all have a unique bottom lip. Whereas most plastic spindle coverings are the same diameter from the top of the spindle to the bottom, Taiyo Yuden cases have a "lip" on the bottom of the plastic covering that starts about an inch from the bottom. The bottom of the clear plastic covering sticks out just a bit and then recesses to the diameter of the rest of the spindle. Taiyo Yudens comes in these cases no matter how they are branded, and I have never seen a spindle of discs with this bottom lip that are not Taiyo Yuden. I guess Taiyo Yuden supplies the plastic spindles as well as the branding on top of the disc.
In any case, I have had better luck with the consistency of Taiyo Yudens than any other brand of DVD+R. I'm not sure what the case is now, since I've only been using Taiyo Yudens for the past few years, but when DVD recording was first becoming affordable, the compatibility of much DVD media with various recorders was so terrible as to be useless (and endlessly frustrating). Taiyo Yuden makes quality discs, and it's always nice to spot them in the store when there's a deal going on.
Re:He forgot the most important one... (Score:3, Informative)
I've lost multiple discs burned onto completely worthless KHypermedia DVD-R media after less than 3 years--two boxes of media that were free after some promotion, yet I was still ripped off.
Re:Safety in Numbers (Score:3, Informative)
No, you will not get "more room". You will still have 1 Terrabyte of the same data copied out over more disks, but still only 1 Terrabyte.
Attribution. (Score:1, Informative)
Re:The secret to spotting Taiyo Yudens (Score:3, Informative)
Web Bug in Article (Score:1, Informative)
afcyhf WHOIS's as part of ValueClick. Most modern HOSTS files block it.
Re:I'm Surprised (Score:5, Informative)
All current forms of optical storage share the same problem that will limit their reliable life span. This problem will effect different media design types over different periods of time, but 20 years is a good average before you will start to see bit rot. How ever ALL optical media, regardless of being commercialy pressed or being consumer grade CD/DVD-R, will eventualy suffer bit rot for the exact same reasons. The problem is that the rate of expansion and contraction of the metal substrates that make up the innner layers and the plastics that make up the outter layers are very different. All optical media will suffer bit rot over time because of this, as what eventualy happens is the metal substrate inside the plastic protective layers gets warped and ripples start to form in the surface. This of course starts to alter the smooth/pit reflection encoding of data on the disc and ruins the data.
Again, different types of optical media design will last longer than others. Yes, commercialy pressed CD/DVDs will last longer than consumer grade CD/DVD-R media on average. How ever none of these formats have the reliability and shelf life of magnetic backup tapes! Espeically newer formats like AIT, SAIT, and LTO (and VXA isn't too bad either, awesome pricing on smaller VXA auto loaders). So if you are looking for reliable long term archiving CD and DVD are NOT what you want to use! You want to use tapes. How ever, you can use CD or DVD if you keep in mind that this format has a shorter shelf life and you plan a migration of that data to a new removable media format say 10 years out from now. You have to do the same thing with tapes too, as eventualy formats become old enough that it gets hard to find tape drives that will read your backups. And yes there is still a limit to the shelf life of backup tapes, as over time the magnetic signals encoded in the tape start to transfer between layers due to the tape layers being tightly wound around each other on the take up spool. How ever, even with that in mind, tapes provide a much longer useful life span for archiving data. And beyond having a longer shelf life tapes have several other advantages. They have much larger capacities than CD/DVD media, so you don't have to sit there rotating tons of discs to restore a large archive. And in many cases newer tape formats have much faster transfer rates than CD/DVD (granted they cannot do random I/O, but burning CD/DVD isn't a random I/O process either). Any one who has serious data to protect shouldn't be using CD/DVD for backup. This is more of a cheap low end consumer approach for those who cannot dish out $1000+ for a good tape drive.
Those who still have the wool pulled over theirs eyes and still think CD/DVDs are a long term storage platform need only look to those of us who have very old CDs and laser discs for proof to the contrary. I know plenty of people who bought some of the first pressings of CD albums back in the early 80s, and many of their earlier CDs are now suffering bit rot. This is even more prevelant on laser disc, probably because of the much larger surface area being affected. Many laser disc owners are fully aware of the problem of optical media bit rot. In many cases the bit rot gets bad enough that you can visualy see the distortions on the reflective surface.
Bottom line, if you value your data then use backup tapes! That's what that technology was invented for! CD/DVD-R is more of a short term backup option, best for cheap short term archiving or transporting of data. I use CD/DVD-R for regular backups of the documents on some of my workstations. But when it comes to our servers and our customer's servers it's AIT or LTO tape drives all the way!! Use the right tool for the job!!
Re:Safety in Numbers (Score:3, Informative)
I'd say that the 4.7TB that $1K will buy, along with the DVD-R burner jukebox, is more than "little bits of data". I already pointed out how to deal with inevitably damaged DVDs.
A 200 disc book can hold a lot of DVD data. For most people, 4.7TB is more data than they own, including all their movies. Since DVDs can actually hold 17GB when double sided/layered, that's 17TB. If you've got more data than that to store, you can afford $10-20K+ for substantial robotic archival systems.
Your attempt to argue with my economics is contradictory only because you didn't understand its plain point. The jukebox costs about $400 (as little as $300). 1000 DVDs cost $200, but only 200 will fit into the jukebox at once. So that first 800GB on 200 discs costs $400 + 40, or about $450 - the rounding error for shipping, and actual price of the jukebox, makes $450 a charitable statement, when it will probably be less.
I'll even parse the next statement you didn't understand. The point is that larger storage than just the first jukebox load quickly becomes much cheaper than HDs. And more incremental, without having to buy an entire 750GB HD to store the next 500GB. Or by spending that money on much more DVDs. Which also bring the the other benefits, including flexibility, that HDs don't offer. And though you don't get it, the point of a pair of jukeboxes is to transfer an entire 200 discs to "fresh" DVDs that haven't aged like the story we're discussing describes. Again, solution to the "expiring DVDs" problem that just uses more DVDs.
I don't know how long the unspecified DVD jukebox would take to burn a full load. So what? The archive is supposed to last for months, years. If you have more frequent archiving demand, use a different tool.
The point isn't "more neat stuff", but the right tool for the right job. Since the job we're discssing is "coping with expiring DVDs", there is a way to just use more DVDs, as I've detailed. There are arguments for using HDs instead, but not necessarily in all situations, or even in most. But then, since you're not discussing the same thing as am I, we haven't gotten anywhere in the point of this thread.
Re:Safety in Numbers (Score:2, Informative)
If all you want it a copy of the current (or the last few) day's disk state, then another disk makes good sense. If you want to be able to restore last December's tape because someone trashed your 1099-processing software in January and no one noticed until today, tapes are definately cheaper.
People like stores. It's not a guessing game. (Score:3, Informative)
Sometimes you need media immediately. Some people like to pick up media at the store. If you're going to be buying it at the store, why not get the good stuff, especially if it's the same price?
Additionally, it's not a guessing game once you know what you're looking for. If it comes in the Taiyo Yuden "That's" packaging and says "Made in Japan", it's Taiyo Yuden (unless it's a cheap imitation, which is still identifiable and not very common). People over at the media section of the CD Freaks Forum [cdfreaks.com] have discussed this to death for years. I will save you from hours of mostly non-productive reading by telling you that the packaging is unique to Taiyo Yuden, that fakes are not hard to spot and will not normally say "Made in Japan", and that most of the people on the CD Freaks forum, who have entirely too much time on their hands and enjoy obsessively testing CD-Rs and DVD+/-Rs with many official and hacked firmwares for dozens of recorders, agree that Taiyo Yuden is the best.
Re:I agree... But where can I find some? (Score:1, Informative)
Taiyo Yuden FAQ (Score:3, Informative)
Re:The usual vague personal testimony... (Score:2, Informative)
Alexander Noe's site also includes error readings from the main brands of DVD+R/-R (including TY) for comparison to your own discs.