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'm Surprised (Score:3, Interesting)
Bummer (Score:4, Interesting)
Safety in Numbers (Score:4, Interesting)
Why not just burn a few copies of the archive to a bunch of DVD sets? The DVDs will get defects, but shuffling the chunks across the discs just a little will probably ensure that the random distribution of specific defects will not hit every copy of a given bit, against the odds a low defect rate will produce.
How about a pair of those archivers, which fire up every few years just to transfer the aging DVDs to fresh new ones? For another $1000, that's another 5 cycles of DVDs, 800GB per cycle. Another $1000 gets a pair of backup jukeboxes.
For higher capacities than 800GB, there are pricier pro jukeboxes, but with dual drives for the retranscription cycle (and faster restores). But the architecture is the same. Why try to make the media more reliable, when there's cheaper/easier solutions that just accept unreliable media, and move on?
Not a concern with MY optical media (Score:3, Interesting)
I have CDs good since 1998 (Score:5, Interesting)
my experience: some DVD media dies with no reason (Score:3, Interesting)
Possibly relevant, I noticed an internal pattern of small spots visible with a loupe or macro lens (on order of 10 microns in size; much larger than the data pits). You can read more about it here: http://www.bealecorner.com/trv900/DVD/Maxell-DVDR
Maxell America agreed to take back this DVD for analysis. As instructed I sent it to their Fair Lawn, NJ site. It was received Oct. 5 2006 and Maxell acknowledged receipt. They have apparently done nothing with it since, despite several emails to them in the ensuing two months.
I use DVD+/-R over CD-R for archiving. (Score:3, Interesting)
Sure, you can handle the CD-Rs carefully and avoid this problem. But wouldn't you rather use a more reliable medium in the first place?
Verbatim DatalifePlus 8x MCC 003 (Score:2, Interesting)
Stay away from Taiyo Yuden 16x media. I'm using a BenQ 1620 for all my DVD burning needs, and the PI/PO tests done on T-Y 16x media using DVDInfo Pro [dvdinfopro.com] have always resulted in low quality burns. I am currently using 8x Verbatim DatalifePlus DVD+R media, and burning them at 4x. The results are truly unbelievable. The media code on the 8x Verbatims is MCC 003. I've heard through the grapevine that T-Y changed their media somehow from their 8x sets to their 16x sets, which has resulted in that the 16x DVD+Rs aren't as good. If you can get your hands on 8x T-Y DVD+Rs, then go for it; otherwise, stick with the Verbatim DatalifePlus series.
-BB
DVD media quality guide (Score:2, Interesting)
Shoddy Article (Score:1, Interesting)
Actually, the pits have a depth of 1/4 wavelength of the laser, so that the light that is reflected from the bottom of the pit travels 1/2 of the wavelength longer and cancels out the light that is reflected from the land.
That would be about 263157894s. or about 3046 days - more than 8 years.
Additionally, I really don't get his argument about the ATIP and wobble. If your DVD-R has degraded so badly that you can't read the ATIP before burning it, you probably don't want to use the disc for long term archival anyway. He goes on about the error correction of the data in the ATIP, but as far as I know, the ATIP is only used to determine the recording strategy, and should be of no relevance to reading the DVD - after all, the relevant part shoud follow the same standard as pressed DVDs so that the "new" DVD-R and DVD+R media are compatible the old drives that predate the recordable media. The same compatibility argument holds for the encoding of the ATIP data itself - if it differs from the pressed DVDs, it can't really be important for reading the medium.
Re:Safety in Numbers (Score:4, Interesting)
Plus, you get a DVD reader and writer. For dealing with the DVDs (and CDs) that still distribute lots of content as a transfer medium. And for those without distributed endpoints to where they can archive data, or insufficient network bandwidth to archive all their data across the WAN frequently enough, DVDs are good and cheap offsite archive repositories. Plus you can burn DVDs that will play in every consumer player, which can connect your data to lots of people without data processing HW. HDs are a cul de sac for data, trapped within the infosystem.
DVD archiving isn't really competition to online HD storage. It's complementary, in different use cases, different user environments. There's considerable overlap in their related extremes, but there's a lot of difference that makes leaves the DVD solution worthwhile for many scenarios.
BTW, while I'm offering detailed factual analysis of HD vs DVD mass storage, don't throw in your "opinion" that "it's absolutely stupid...". Especially if you're going to offer a disagreement worth considering. Do you want to work together to figure out the real merits in a debate, or do you want to get into an obnoxious pissing contest that few other people will want to wade through? Few people worth teaching will learn anything from such unnecessary conflict. Including ourselves.
Re:Bummer (Score:4, Interesting)
Re:Safety in Numbers (Score:3, Interesting)
But what happens if a DVD gets corrupt? Or scratched? Or, lost?
"Plus, you get a DVD reader and writer. For dealing with the DVDs (and CDs) that still distribute lots of content as a transfer medium. And for those without distributed endpoints to where they can archive data, or insufficient network bandwidth to archive all their data across the WAN frequently enough, DVDs are good and cheap offsite archive repositories. Plus you can burn DVDs that will play in every consumer player, which can connect your data to lots of people without data processing HW. HDs are a cul de sac for data, trapped within the infosystem."
Ok. A DVD Reader and writer. Woohoo. For little bits of data, yeah, ok, DVDs are good. But if you are archiving data, say, lots of data, do they work? What about getting data off bad ones? I've tried getting data off a damaged DVD once. It wasn't pretty. At all.
"DVD archiving isn't really competition to online HD storage. It's complementary, in different use cases, different user environments. There's considerable overlap in their related extremes, but there's a lot of difference that makes leaves the DVD solution worthwhile for many scenarios."
For some, yeah. I use DVD to archive a lot of projects, but at some point, it seems to make sense to consolidate all the DVDs. I think maybe when we can burn 20 gigs a DVD or more, it would make more sense.
BTW, while I'm offering detailed factual analysis of HD vs DVD mass storage, don't throw in your "opinion" that "it's absolutely stupid...". Especially if you're going to offer a disagreement worth considering. Do you want to work together to figure out the real merits in a debate, or do you want to get into an obnoxious pissing contest that few other people will want to wade through? Few people worth teaching will learn anything from such unnecessary conflict. Including ourselves."
Your first "factual analysis" included "Cheap but adequate DVD-R media costs $200 for 1000 discs, about 4TB capacity. And a cheap DVD-R changer jukebox costs under $500, about 800GB per load." which is more expensive than a HD. Then you say it $450? Which is it? I think it's more like $450 (jukebox) + $40 (200 DVDs). Then "How about a pair of those archivers, which fire up every few years just to transfer the aging DVDs to fresh new ones? For another $1000, that's another 5 cycles of DVDs, 800GB per cycle. Another $1000 gets a pair of backup jukeboxes." which, doesn't make sense. If you are just going to "fire then up every few years" why not just use a HD? Or two HDs? Just seems a huge waste of time (burning all the DVDs), and effort (loading/unloading) to get what benefit? To say you have all that neat stuff? How many hours would it take to archive all that stuff? I'm thinking days......week? Two weeks with verification after burn?
I'd just stick to hard drives, and have intervals where you'd check out the data, and every 2 years or so, consolidate data on a newer bigger drive.
Re:Patrick got his bits wrong... (Score:2, Interesting)
The usual vague personal testimony... (Score:5, Interesting)
Everyone says "I've never had any trouble with brand ABC," but the thing is, ABC varies depending on what you read or who you talk to. Some people insist they've never had any trouble with the cheapest generic products they buy at Staples. Some say any name brand is OK. Some say Verbatim is good. Some say to stay away from Verbatim. The more sophisticated will tell you not to use anything but phtalocy- pthalocy- pffthal- the Mitsui stuff. Others (like this guy) are partial to other dyes. Some say you're a fool to use anything but Mitsui Gold... some say they're an overpriced waste of money.
It's all authoritative sounding talk, talk, talk and no two experts say the same thing.
In reality, I don't think anyone understands very well what actually causes these disks to fail in the real world. I've had disks fail in less than two years--maybe only a couple-three in many hundreds, but certainly not zero--and I've never seen any obvious pattern as to which of them fail.
The thing that really bothers me is that drives and/or their accompanying software drivers never give you any indication of what the signal quality of a particular disk is. If they did, you could detect that a disk was deteriorating before it failed, and make a copy. As it is, they just keep silently keep correcting errors behind your back and you have no warning until there is utter, catastrophic failure.
Re:This bears repeating (Score:3, Interesting)
If you have a large organization and you're backing up terabytes+ daily, then yes with incremental. You can probably afford the $37,000+ for a TB storage solution.
A good bit of small businesses really don't have more than a couple hundred gigs that need to be backed up and the nightly stuff is probably under a gig unless you're in the media business.
Tape backup for archival is a horrible solution. You're dependant upon the media and the media player and in the case of Microsoft, the OS as well. BackupExec issues anyone?
How many of you had that backup you made to tape take forever to retrieve where that happenstance copy you made to another server work just fine?
Tape backup for `backup` is a fine solution but not for long term storage.
When marketing companies are finished with projects and they need to be removed from the server, they are archived on CD/DVD media.
If is probably cheaper to buy about 20 500 Gig Hard Drives and run a backup scheme using that media than to spend $2,000 on a 120Gig DLT tape drive that will take 6 hours to make a backup.
I'm not really discounting the usefulness of tape backup, I just question if it is relevant today when disk storage is cheaper.
My
Re:I use DVD+/-R over CD-R for archiving. (Score:1, Interesting)
Re:Bummer (Score:3, Interesting)
Of course, I expect the requisite *woosh* response to my own post, but at least be kind and explain what I've missed when you do.
Re:par2 (Score:3, Interesting)
Maybe not. PAR2 files store the filenames as part of the recovery data. As long as the TOC track (innermost track) isn't kaput, you can recover the data even if both the UDF and older 8.3 file tables are blitzed. If the TOC is busted, you'll have to get a professional DVD reader or go to a recovery service.
(The "how to" is over on the QuickPar forums. Basically, you rip the disk at the sector level to a pair of files. Rename the one with a PAR2 extension, then feed it the 2nd file as source data. QuickPar will find all of the data blocks and reconstitute the original files.)
UDO Archive Appliance (Score:1, Interesting)
Why not just get a NAS that has RAID? That would make more sense. When a disc dies, you can replace it, rebuild your array, and everything is fine. PLUS, you could expand your archive over time.
How about NAS RAID and UDO [plasmon.com] all in one system, the Archive Appliance [plasmon.com].
independence (Score:3, Interesting)