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NIST Releases Study Of CD/DVD Longevity
dirkin writes "The National Institute of Standards and Technology has released a preliminary study of the potential lifespan of CD-Rs and DVD-Rs. The PDF study is here. A good starting point for deciding what type of media to purchase to keep those backups and photos kicking around longer. (You DID buy the silver/gold alloy phthalocyanine CDs, didn't you?)"
the speed in which the CDR is burned sometimes it makes a difference, for the highest reliability I think 1x is the best.
RAID?
;)
Just about every solution is an endless blackhole of money to keep that data around. Hey, there's always tape
------
Free your mind
My pr0n my precious precious prOn!
Take multiple backups and atleast have one backup on high quality CD-Rss not the 25c a piece ones.
Keep upgrading your Harddisk from time to time and backup data from old HD to new one.
for the last time people, I am "frodo from middle eaRTH", not "middle eaST".
Strange all of my disks DO work - even after 3 years.
Almost all of my no-name disks are dead after 3 years. Some of my verbatims are dead to. Hard disks at 1/gig now seems cheap compared to my dvd writer and 20c per gig disks. My bet is those optodisk-RW will be dead in two years.
Man, finally a study that backs up my suspicions.
I have had many a music CD go and then blame it on scratches or whatever.
I wonder how this compares to DVD-R?
--Dweebs
treat them like a mushroom and keep them in the dark.
I have many CD-R discs that are still quite readable despite being 4-5 years old. On the other hand, I've seen a disk erase itself in less than a day when left in direct sunlight, and many disks will slowly degrade at light levels found in most human-occupied spaces.
Lots and lots and lots and lots and lots and lots of floppies.
Jonahweb.com has stuff.
Just put your stuff on an FTP site and let the world do the backup for ya.
All of mine from the 80's and 90's still work.
Just backup to harddrives.
I'm using Araid99-1000 units in my computers, and backup is just replacing the slave drive (even while the computer is on and running).
The price for say, WD120mb drives are so cheap now that it is probably close to the cheapest, safest and most accessable backup format available.
Well - if you recall tape drives were the "big thing" in backup about 5-10 years ago. I have looked at 10 year old tape backups & they work just fine. Maybe we need to trust good old reliable tapes. Or the other (faster) solution would be external hard drive backups.
===> An eye for an eye makes everyone blind - MG
Just do what I do : buy a rack, install in front of your machine (under the DVD or CD-RW or somewhere) and back up all your important data (or your entire harddrive) to a separate harddisk. Prices on smaller models (40-60 gigs) aren't all that steep, and most people I know have trouble just filling up their 'small' 20 or 30 gig drives. A spare 60 gigger rackdisk will keep you satifsied for a long time... Alternatively you could also just buy an external fire-wire or USB harddisk, although I don't really have all that much experience with those kind of devices.
Simply buy twice the number of drives you need, and do an rsync between the two sets now and again. For added safety, get a friend with broadband and store the second box there. Then you are safe from fire, theft, drive crashes etc, with minimal effort to keep the backup up to date.
I've got a whole load of burned CD's that I created up to about 5 years ago.. and on varying quality of media, and a lot of them aren't any problem.
I suppose storage is the key thing, keep them in a dark cool place will help them last just that bit longer (unless you have a case of those little bugs that like eating the data layer).
Although they are of a similar tech, what about DVD recordable disks? I've got plenty of those now... but if I keep doing what i've been doing over the years and backup my backups onto newer media then I'm not too worried.
Just my $0.02
Are you local? There's nothing for you here!
This doesn't tell us much. It's almost a teaser. "Are you going to die tomorrow? The answer may surprise you. Stay tuned for News at 11." I have some CDRs that stopped working within days and others that have lasted over 4 years now--same brand from the same spindle even. I wonder if the full Dutch article gives specifics or if they found _any_ CDs that were still working fine after twenty months. The teaser seems to suggest that they're all terrible. I do know that I get fewer duds now that I use Toast than I did when I used "Easy CD Creator." Beyond that, I don't know anything that makes a difference. CDRs stop working. DVD-Rs are crazy fragile. Hard drives fail. Paper burns. Maybe my data wasn't supposed to last forever. Alex.
I am not suprised by this. It is easier to scratch CD-R's than CD-ROMS. I have corrupted many CD-R's just by scratching the CD on the CD tray itself. In addition, CD-R's are written with ink(as opposed to plastic CDROMS) making it much easier for them to go bad.
The Television Wiki
i'm scratching my ass all day...
WTF happend?
I have been using them for over 5 years now... no problems what so ever, but hey I didn't buy the cheepy CDRs you know!
I have/had a few website backups. They are about 4 years old. One day I thought it would be fun to see what they looked like, but I was unable to mount any of them. I tried another machine to see if it was just the drive, but the other machine could not read it. Well I don't really need the data on them. But I guess you can't rely on them for storing your financial data.
So I guess I have to rethink how I am going to store those pictures from my new digital camera. I guess one have to copy the CDs from time to time.
It's a good thing I make nightly backups using PaperDisk!
http://www.paperdisk.com/
And people would laugh at me with their CD backups. We'll look who's laughing now!!
---
Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves. -- AE
I have had many CD's that have worked for 5 + years. These are the ones that I only use every once in a while and are kept in jewel cases. The ones where I just burn like say a driver for a network card on a computer that is not on the network yet or other things sneaker netted over I could care less about. My backup for my data that I really need/want is on my Nomad Zen. But I do have several CD's that are pretty old and the data is fine. These articles are pretty small, so I would not put much faith in them. Now if someone else did a truely scientific stufy on them and found this (charts and all) I could possibly pout more faith in it. To those who thing it should be possible to mistreat a cd and expect it to be readable, you have GOT to be kidding!
Gorkman
This article is quite inconclusive in my mind. There is nothing in it that describes the care given to the cds for the past 20 months (what cases, if any, they were in, the amount of light and heat they were exposed to, etc.) Also, there was no mention of the quality of the media they were burned on, nor the speed at which they were burned. Too many variables are introduced in the article to fairly say that cd media is not a viable backup alternative. It seems like decent advice to burn slowly and simply take care of your cds, they would last much longer.
I've had cheap brands of CDs (you know, the ones where a 200 pack is $30 normal price, free after rebate) actually get holes in then after many reads. I've also had ones that have warped. I have had the best luck with the name brands. However, the best cheap/free after rebate brands, in my experience of getting them free every week at OfficeMax:
1. Kypermedia - a very nice product
2. E3 works - never had one fail
3. Iomation
And the worst possible: ValuDisc
Good thing I saved all my stuff to LaserDisc !
That researchers will say anything to get published.
Have any of you ever had a CDR become unreadable for any reason other than scratching it? I sure haven't, and I've used CDRs on a regular basis for 5-6 years now.
P2P the ultimate backup medium on the cheap. Why pay when people will back it up for you for free!
:P.
Hell I guess that's why all my DVD's, CD's, home made porn, and scanned images of my squashed face end up being backed up to. And all it costs you is bandwidth and a RIAA law suit
What a deal!
GPLv2: I want my rights, I want my phone call! DRM: What use is a phone call, if you are unable to speak?
Has anyone tried to create a P2P backup solution? Like a gigantik P2P-RAID with cryptated data.
I have some CDR-disks from early 1996, several from 1997-2000, and a huge pile from 2001-today.
None have shown any sign of damage up to date.
Maybe its my cautios way of storing them, I just leave them in the spindles after burning, 50-55 per Box. No direct sunlight, but surelly some indirect one.
Save it to film.
www.bannination.com Two things float to the top he
This is really something to think about.
I have lots of CDs with photos and other things that I really don't want to be destroyed because of a 'flawed' media.
Is an harddriver safer in a long run than CDs? Or is the only safe thing a RAID solution? Printing each photo on paper is not an option though.
Since it was already taking 30 seconds to feed me the page, I might as well copy what I got..
CD-Recordable discs unreadable in less than two years
Posted by Dennis on 19 August 2003 - 14:33 - Source: PC-Active
The Dutch PC-Active magazine has done an extensive CD-R quality test. For the test the magazine has taken a look at the readability of discs, thirty different CD-R brands, that were recorded twenty months ago. The results were quite shocking as a lot of the discs simply couldn't be read anymore:
Roughly translated from Dutch:
The tests showed that a number of CD-Rs had become completely unreadable while others could only be read back partially. Data that was recorded 20 months ago had become unreadable. These included discs of well known and lesser known manufacturers.
It is presumed that CD-Rs are good for at least 10 years. Some manufacturers even claim that their CD-Rs will last up to a century. From our tests it's concluded however that there is a lot of junk on the market. We came across CD-Rs that should never have been released to the market. It's completely unacceptable that CD-Rs become unusable in less than two years.
On the image you can see the exact same CD-R. On the left you see the outcome of our tests done in 2001. On the right you see the same CD-R in 2003. The colours indicate the severeness of the errors in the following order; white, green, yellow and red whereas white indicates that the disc can be read well and red indicates that it cannot be read.
For those of you who are interested, the original Dutch article can be found here and in the September issue of PC-Active. Please discuss this subject in our Media Forum.
When modding "Informative", please make sure it both has a source and IS actually informative.
Do backups to a raid system. Even IDE raid with only mirroring, just throw the data there every now and then.
:)
And don't use it too often for regular usage if you can help it.
By backing up to it and unmounting it once a night, you run less chance of corruption due to power outages, kernels going nuts.. generals going nuts...
Sorry.. too much strongbad. I guess this is where I'd mumble something under my breath. gah!
--
"I'm not bright. Big words confuse me. But Wanda loves me and that should be enough for you." - Cosmo
Or, rather literally translated into English: "Our sample shows that there is a lot of junk on the market. We have found cd-rs that should never have been for sale. Possibly it concerns rejected batches." Which suggests to me that the correct heading of this article should be: CD-Rs are like everything else: you get what you pay for.
What speed was used to write the CDs?
Were they all stored in the same place?
Were they all burned by the same CD burner?
Were they all burned from the same source (a single CD, hard drive, network, etc.)?
30 CDs sounds like an epidemic, but since they were all burned at the same time twenty months ago, there could be a lot of other reasons why all of these discs would go bad. If they were all burned at the same time, then they're effectively talking about one batch, regardless of how many different CD-R brands were used in that single batch.
Does the Dutch article cover this or is this just a scare story?
Take now into account earth's rotation and its magnetic field. It induces an albeit very slow movement of the molecules - the data layer degradation. The same effect causes btw certain currents in the Pacific oceans. While the movement is very slow and in the case of the ocean not very important, it does cause damage after a certain amount of time in the case of a CD-R. You should remember that the scale of the information storage units on a CD-R is in the nanometer range. The information is just "washed away" in an entropy-like effect.
However, you can slow this movement down. The molecular movement in the data layer is directed. So it can be reversed to a certain degree just be placing the CD-R the other way around. So, all you have to do is to mark the position of the CD-R in your rack exactly. And reverse it's position every month or so. This can increase to the lifetime of a CD-R about 150 percent. More can't achieved (in normal environment) because electric machines like your computer etc. create their own electro-magnetic fields. And the effects of these varing fields are much more difficult to negate.
BTW: the 100 percent wrong place to store your CD-Rs is on the top of your CRT.
Owner of a Mensa membership card.
Just test it:
http://rdiff-backup.stanford.edu
Remote incremental backup system over ssh with recovery points management. (GPL'ed Python script)
Anyone know how DVDs compare for reliability?
Well I am not sure the 2 year limit applies to every brands of CD-Rs out there. I for one knew some of the CD-Rs are of better quality out there. Another thing is the burning speed could be crucial: 1x recording might be a bit conservative (actually for many CD-writer nowadays 2X/4X is the minimum writing speed) but any burning speed > 12x tends to produce C1 or C2 error sometimes. I personally choose a writing speed of 8X most of the time.
Things with moving parts are always prone to failure. I have had excellent luck with the 512MB flash drives - they still have a lot of space, they can be random rewritten, and there are no moving parts.
Something big is happening. Maybe the collective stupidity and arrogance of SCO execs reached a critical mass and the whole company just imploded into a black hole of stupidity. Or may be their IT staff is in open revolt. Go, SCO geeks, go!
This is shocking, and makes me wonder how should I backup my data, photo and music collection.
How about more than once every two years for a full backup? And given that hard drives are already commonly storing two magnitudes more data than a CD can, in two years we'll all have said goodbye to our CD-R anyway. But I have a feeling people around here will still bitch when Apple removes them from their line, while the PC shops will still be shipping that damn floppy.
Stop the Slashdot effect! Don't read the articles!
And it is true that 40% of my 3.5'' floppy discs are not readable anymore, but I have copied them to CD years ago. And I will copy my CD-Rs to blue-ray, or whatever comes next. In reality, who the fuck cares is the CD-Rs are still readable in a few years. This is true for my private stuff as well as the CD jukebox we use at work.
And BTW, two years is just rediculous. I have CD-Rs older than that and they still install debian. When it comes to audio or even DivX video, it's not even a serious problem if there are a few unrecoverable read errors.
Cheers.
KdenLive/PIAVE - non-linear video editing
Don't forget to have one or more off-site backups (encrypted in case they are stolen). I keep one off-site backup (on CD-RW) in town, at a friend's place, and swap it for a fresh backup every time I visit him. (Be sure to offer to do the same for your friends.) An out-of-state backup gets refreshed every time I visit my folks.
It's peace of mind knowing that if, heavens forbid, anything catastrophic were to happen to your place of residence, or if burglars were to take your computers and disks/tapes, then you would at least not have completely lost all of your critical data.
FWIW, I can't remember having a single CD-R go bad. I've had some scrathed ones which took a while to read because the reading drive slowed to a crawl, but I got the data nonetheless. I even recently found what must have been one of the first CD-Rs I've ever burned. Must have been from around '96 or '97, it had my backup copy of Duke Nukem 3D on it, among other stuff, and everything read fine (the disc was a Sony CDQ-74CN).
Did you know you can fertilize your lawn with used motor oil?
Looks like they didn't account for different recording speeds.
Slower recording speed = more reliable, though there are still bad cds that'll go bad quickly no matter what you do.
I have some Verbatim CD-R's, both data and audio formats, from 1999 that still work to this day. I don't know what brand this study used, but I haven't had a problem with Vertaim or any of the other "expensive" CD-Rs.
--If only there was a license required to use a computer.
Back in the eighties, when regular CD's were first introduced that could be read by a standard computer (pc, mac, etc), the discs were fairly thick, and consisted of (iirc) from top down:
disc label
protective coating
data layer (usually pressed)
protective coating
Then at the end of the eighties, I don't recall exactly what year, but it was adopted by various cd makers till eventually all, the price of CD's dropped dramatically, almost in half.
The reason for this was the fact that the top protective layer was removed from the manufacturing process, leaving just the thin disc label and it's material to protect the data layer, barely.
I want to clarify that I'm talking about regular PRESSED cd's manufactured in bulk, and not dye layered ones, but the point is the same in both cases. By removing the top protective layer, it allowed manufacturing of CD's to drop in price dramatically.
I'm positive there have been other cost cutting measures used for dye layer CD's that the manufacturers have adopted over the years, such as cheper dyes that are affected faster due to exposure to sunlight, and so on.
It's not just about scratches or dye, but about the overall picture here. The manufacturers WANT to have built in obselesance. This gives them a nice steady flow of income when one has to contually burn his media archive every 2 years.
Food for thought anyhow. I thought I'd post about what I saw in the eighties, in case it was relevant.
user@host$ diff
For serious backups, I wouldn't be using a harddrive.
This was a discussion here before about this subject
The surprise isn't how often we make bad choices; the surprise is how seldom they defeat us.
I've been burning CD's for years at work, and I still often use the earliest ones, the ones with drivers and old files on it. They ALL still work. But just in case, I'm gonna use this article to requisition a new backup device.
Oi! Yes, you! Tell me what has happened to SCO?
I have perhaps 8 Sony CD blanks that apparently were attacked by fungus. I kept them because maybe they can be analyzed to understand what went wrong. We never bought Sony CD blanks, the blanks came with CD-RW writers.
Since we don't buy Sony writers any longer, and never bought many, I can't say if that is an ongoing problem.
Anyone else having problems with the quality of Sony products?
I found it odd, though, as they said they couldn't tell the public their findings. This point stuck with me, but I forget the exact reason. Perhaps it is simply that it would influence the market? Wouldn't make sense to me: the taxpayer probably put up the funds for the tests and the public and the market would both benefit from the results. Maybe NIST got some industry money to do the test with the condition that the results be kept secret.
Anyway, it would seem they probably have done the same for CD-Rs.
The translated article is short, because the original one was short too. I just glanced over this translation, but I think it was complete.
I fear that If you want more information, you should buy the magazine itself.
No, I am not going to buy it. I have broadband.
That's because you're using hastily slapped together plastic/aluminium/dye sandwiches from the infamous Coaster Manufacturing Company - CMC Magnetics, and the other shit brands. They're cheap for a reason folks - the same thing happened with floppies.
Try decent discs. Two words: Taiyo Yuden - the very best there is. When you absolutely, positively got to be able to read the data in five years - accept no substitute.
Don't believe me? Track some down. Burn on them. Put them side by side with a crappy CD-R. Spot the difference. Test them. Notice that with many drives you'll get zero C1 errors. Test them in a week. A month. A year. Notice that if kept right, and they don't deteriorate suddenly, they should still be C2 free in twenty years.
Crappy media has crappy quality control, and thus tends to fail quickly. This isn't news, it's just the way it is.
I wonder if this Dutch study used those cheap CD-R's that have the silver front and no brand name anywhere on the CD itself.
--If only there was a license required to use a computer.
Perhaps those unprotected CDs can be protected somehow? For example, if I covered the unprotected side with a thin layer of lacquer or some other coating, would it help the CD remain readable for a longer time?
I'm feeling curious if other people tried something like this and what their results were.
I used to work for a company in Austin, TX whose speciality was optical drives (not CDs, but WORM mostly), and one of our customers was the National Archives. This was when CD-Rs were just coming out, and the NA was interested in a cost/benefit analysis of whether or not they could replace their expensive 14" WORM systems with cheap CD-Rs.
The first thing to understand is that WORM systems, true WORM systems, not the Magnetic-Optical pseudo-WORM systems, are built on ablation of material in the disc itself. In other words, you burn holes in the disc revealing a lower layer that is reflective. In the case of most discs, and Kodak especially, they were gold on the reflective layer for long-term stability. Various tests of accelerated degradation were performed in both climate stabilized and non-stabilized situations, and at worst, the discs were stable for 100 years before any error correction was necessary.
We decided to perform the same kind of evaluation of CD-Rs, and found that brand varied greatly. The best were stable for 3-4 years, the worst only 6-8 months if the climate changed dramatically. In addition, UV exposure had a radical impact on the life-span of the disc. Further research found out that the problem was the natural instability of the organic dyes that were used in the disc layers.
Basically, if the disc wasn't perfectly sealed (look at the work done in the referenced article, and how it starts at the edges), oxygen would get in and react with the dye, which would change it's characteristics relatively quickly. It doesn't take much before the dye structure collapses, and data becomes unreadable after a short period. While I suspect the dyes have gotten better over time, they're still organic last I knew, and still subject to degradation by contact with air. Quality control is the only thing that will get you anything here, and I suspect even the best dye-based discs can't make it past 20 years unless exposure to UV is totally eliminated.
What Kodak had developed was what they called "Century Discs", which were basically scaled down WORM discs, but in CD-ROM format. They were gold inside, non-reactive, and well made. They did, however, require a very expensive writer because they needed more power than a CD-R drive could ever hope to provide to force the burn away the spots. They were, however, readable in a normal drive.
That's just my experience, but everytime I've seen an organization talking about "archiving" on CD-R, I have issues with it. It's fine for "backup," where the data cycle is shorter, but true archival purposes (for example, financial data), it won't cut it. You either need to use WORM, or tape. Tape is, however, subject to problems over the cycles as well, witness the failing properties of 9-track tapes written by NASA in the 1970s (heard first hand, not sure where to find it written up). Linear-write systems are better than helical.
Just a few thoughts, but this is not an easy issue. You have to understand what you're storing, and how long it has to be readable before you consider an actual medium for storage.
Having owned and used a CD writer since about '96, I've got quite a selection of backups and music cd's from over the years.
A cheap highschool student, I was always on the lookout for the cheapest CD-R's I could find - no name brands and auctions on ebay. I'd just like to point out that, contrary to this article, almost all of the old CD-R's that I have still work, unless I scratched them or dinged them up pretty bad. I don't seem to have any problems with decay.
Maybe I'm just lucky?
-dave
http://millionnumbers.com/ - own the number of your dreams
...to your web server in just a couple of minutes.
"Smoking helps you lose weight - one lung at a time" -- A. E. Neumann
yep... the PS2
used to include a study of glove compartment temperature cycles for their high end discs...
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
Holographic storage is almost here. Just more wasted tax dollars on a technology that will be obsolete by the time the media wears out (unless you own ancient cds).
You DID buy the silver/gold alloy phthalocyanine CDs, didn't you?
No, I've not ever ran across them, and it's not like they print the reflective layer and dye compositions on the side of the package. Mine are always green-ish.
(fp?)
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
Mine will be kept on a real Hard Disk. What I have now is a 120GB, 7,200 rpm Maxtor HD, which has never disappointed me at all.
Discerning pr0n collectors choose silver/gold alloy phthalocyanine CDs.
Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)
http://www.lawrenceperson.com/
I still think that corn CDs are the best idea... you'll just need to reburn every once in a while.
It only becomes a problem if you're a big nacho fan...
They seem to still be very readable. I don't get all this "only lasts a year or two" crap about CDRs. Obviously this is false.
Meh.
CDRs and DVDRs? I used to back things up on Kodak Gold CDs but I can't find them anymore :/
-- the cake is a lie
Yes, I did buy gold CDs. Until they stopped being sold around here...
I'm backing up onto my CDR now so I don't lose it. I advise the same to everyone else.
I look forward to over 2000 years of stable storage without data loss!
Yeah, right. Didn't you see Raiders of the Lost Ark? The Ark was full of dust.
At least you'll be able to melt some Nazis though.
The coolest voice ever.
The PDF doesn't seem to suggest any particular brand to get, only says that 'D2' DVD-R's performed very well. Does anyone know which dvd manufacturers make this type of media?
I have a lot of CDRs that are 15+ years old and still work. These are the cheapest CDRs too from back then (which were still expensive).
actually, I was going through my legally obtained mpeg-4 backup CDs earlier this week, and found a number of Discs had irrecoverable errors on them, despite having been kept at room temperature, in cd sleeves, and having no scratches. The longevity of cheap to medium grade CD media is not nearly as high as you'd think.
that buying cheap crappy CD-Rs meant that your data died faster, but I had no idea how the degredation worked. What about the "armored" DVD-Rs from places like Datawrite? They're supposedly almost impossible to destroy. How well do they stand up?
I rarely backup onto such media. I just buy new computers with more drive space. Or add drives. RAID works, drives get cheaper way beyond the rate I generate content. And yes, i am aware of the benefits of off-line storage.
With the study subjecting discs to extremes to cause them to fail, they've shown relative tolerance to certain conditions, but we still don't have "burn to these CDs and keep temp between 60 and 80, RH between 10% and 50%, and light to a minimum and they're good for 10 years" kind of numbers...
500GB of disk, 5TB of transfer, $5.95/mo
I know I shouldn't feed the trolls, but...Wow, that's mature. It is an open standard, with free (both open and closed source) readers for virtually every platform in existence. The paper contains images, charts, and so on. PDF is a perfectly acceptable choice, particularly if it was a report which was not originally designed for the web.
Unfortunately, seems they slightly missed the point- the charts and other line art...well...aren't. They're screen-resolution bitmaps. Oh well.
Please help metamoderate.
I have some Kodak Gold CD-Rs stashed away for archival masters. I have no idea how long the DVD+Rs and DVD+RWs will last.
Mea navis aericumbens anguillis abundat
Where's the kharma whore with the summary when you need them?
I just write mine down as ones and zeros on paper. It takes me a few months to do a full system backup, but it would take the government years to accomplish the same task. I figure I'll be saved by the statute of limitations by the time they figure out what I've been doing.
...papyrus. That, or clay tablets. Nothing else comes close. And I'm not joking.
Tubal-Cain smokes the white owl.
I found this very old dupe: http://slashdot.org/article.pl?sid=04/04/22/165825 1&tid=
All those Netflix movies I've burned will essentially be worthless!
If someone says he and his monkey have nothing to hide, they almost certainly do.
...I guess I'm the oddball here. I've never thought of any of these media as permanent storage. In fact, I learned quickly very early on that all are susceptible to wear, damage or degradation. CDR/W and related tech are more a bandwidth-saving item or convenience item than anything else to me. The things that I need to save, I move to newer formats, usually multiple copies if it's important stuff.
I've yet to lose data to media degradation, however I once lost some important accounting data to a hard drive crash, followed by two ZIP disk backups that were killed by "click-death". One in a billion shot, I guess. Well, I didn't exactly lose the data, I had hard copies on paper, apparently the only semi-permanent storage media that's trustworthy.
Fred
"A fool and his freedom are soon parted"
-RMS
I suggest you get a little cozier with your browser configuration options...
In Capitalist America, bank robs you!
I wish they would test the Memorex black cd's. If you scratch the non-readable side of them, they are actually gold. I've been using these for the past year or two. The price is good on them, and I've had no problems.
Need Free Juniper/NetScreen Support? JuniperForum
"Only wimps use tape backup: real men just upload their important stuff on ftp, and let the rest of the world mirror it."
vodka, straight up, thank you!
As others have noted, the technologies used in the media are never printed on the packaging. Furthe, like many commodity items, the wrapper has nothing to do with who actually made the media. One spindle of Brand Y disks can be made by Manufacturer A, and the spindle twice its size, with the same labelling, also from Brand Y- will be made by Manufacturer Z. It is extremely difficult to be an educated consumer under these conditions.
It happens in lots of other places- gasolene is not "made" by Mobil; Mobil, Hess, Shell, Sunoco etc contract to area distributors. The distributors buy from whoever is the cheapest or distributes to their area; they slosh-mix any company-specific additives, if any, on the way to the station. Milk? Guess what- federal law requires that the bottling plant's registration number be printed on every bottle of milk. Next time you're in the store, notice how the brand name and generic store brand milk have the same prefix on that stamped number? Notice the brand name milk is pretty expensive compared to the store brand stuff? Dirty little secret of the milk industry, in plain view.
When I need CD-R/DVD-R media, I don't want to have to spend an hour sitting on some webforum reading posts to find out what the most reliable media looks like this week and where to buy it. I want to walk into a store, see "gold type cyno-whatever", see it's $2 more for a spindle of 20 than the other stuff, and walk out.
Though I'm sure there is collusion among manufacturers at the moment, it's only a matter of time before one manufacturer realizes they can market their product based on media type/chemistry thanks to this report educating buyers (the major PC mags will probably pick this up in an issue or two).
What bugs me is how bad my DVD-R disks SMELL. I have to hold the spindle at arm's length when I open the cakebox, and leave the room until the disk is done, because it reeks. I want to know what the hell makes it smell so bad...or, then again, maybe I don't...
Please help metamoderate.
Mitsui licensed the process to Kodak, and still sells the Gold/Silver CD-Rs under either the Mitsui or MAM-A trade names.
They released it on a CD, so its not readable..
Older discussion: Say Goodbye To Your CD-Rs In Two Years?
afterdawn had a discussion on CD-R brands a while back. In short, go with Taiyo Yuden. And to identify Taiyo Yuden?
The biggest issue IMO isn't the media, but the readers. So what if your CD-RW is still readable in 20 years if you can't even find a CD-ROM around to read them with?
I still have tons of 5" floppy disks around, and I'm sure the data on them is usable, but getting it off is another story.
In fact, if I had enough space, I would back up my commerically manufactured CDs and DVDs, given the horror stories I've heard about their crappy longevity. The MP/RIAA wants you to re-purchase all the content they've sold you every 5-6 years. Screw 'em.
Computers are useless. They can only give you answers.
-- Pablo Picasso
This report fails to address the fungi that grows on my cds, as originally pointed out by Dr. Trías.
HAD
Ain't that the truth. We'll probably have collapsible flyin' cars first.
DVD-R media is probably the hottest market right now (even NIST/LoC admit CD media is nearly useless in terms of storage capacity), and note that NIST used the least number of samples, couldn't get any information on composition other than "it's Cyanine based" (gee, thanks), and DID NOT name this mysterious "D2" sample that was so much better than the others?
Sounds like NIST doesn't want to burn any bridges. Not even a mention of dual-layer media, either...I'd love to see how long that stuff lasts, especially since it's something like 5 times more expensive than single-layer media.
Please help metamoderate.
did you ever go to the store and pick up a cheapo blank and a super high grade? you can feel the weight difference. you can also tell with older movies that are sold for under $10... they always weigh nothing. VHS tape is magnetic media (like audio tape)... generally speaking the heavier it is the better the quality. the higher quality ones also will last through more playings/recordings. i am not sure if either are better for archiving though.
with CD-R media i have heard some claims that the black ones are good (look like a playstation game) if they will go to people that have a tendency to leave disks all over their desk... the black plastic lens keeps harmful light off the media surface.
test brands yourself... leave a few on your dashboard through the summer and see what the sun and temperature swings do to them.
recycling in the transporter pattern buffers, locked in diagnostic mode.
Betcha dinna know eeets gude fur 75 yearghs! - Scottie
I love my Taiyo Yuden disks... I like to master audio to the HHB manufactured ones.
I've had a lot of cd's bubble & pinhole on me, even store burned media is cheesy these days. I don't trust cd's at all.
html has a helluva lot smaller footprint...
"I just write mine down as ones and zeros on paper." And you remember to use 100% cotton acid-free neutral pH archival paper.
I'm not a Troll, it's reverse psychology.
So what do i use for backing up data I want to keep for years?
CDr's now "suck".. I just moved alot of data off OLD hd's i had sitting around. They worked fine when i put them away but alot of them failed to spin up or had big time read errors. I thought moving everything to CDr would be the way to go.
I also use a RAID setup on netbsd with a few new seagate drives. Seems to be working fine but a good spike or other big hardware failer could knock the drives out... and just putting one drive away gets me back to my 1st problem.
So what do use?
I have to return some videotapes...
My 18-month old 120GB, 7,200 rpm Maxtor HD packed it in two weeks ago for no particular reason. I have partial backups on CD but stopped backing up several months ago when I found out that the CD's don't last. I was trying to figure out another approach to backup when this happened.
I have used numerous hard drives over the last 12 years and used to replace due to space. More often these days, I replace due to failures.
So the RIAA need not worry - disk drive and CD manufacturers will take care of their little problem by engineering reliability out of their products.
The first HD I bought was a 1.6GB WD Caviar. Still in service, almost 8 years after purchase ;-) Then I bought two disks, one from IBM (30GB DeskStar from the (in)famous series) and another from Seagate (60GB Barracuda IV), and they both failed after 2-3 years. Depressing, isn't it?
"Long run is a misleading guide to current affairs. In the long run we are all dead." (John Maynard Keynes)
I uses 1's and lowercase l's. That always confuses the feds.
Dude, I think I can see my house from here.
(NOT a joke post)
Is it true with many things that reflect light, that the less light it throws back, the more it ABSORBS?
--meaning here probably, that absorbation is what degrades the medium.
I mean, I've had both "dull" and "blinding" discs, (some light-green one's that basically didn't shine at all once "shone on",) and the EXTREMELY reflective one's, that would practically blind you, to some extent.. --I mean, when angled towards a tungsten bulb, or flashlight, whatever..
-Get the drift? --Maybe this is of some importance, don't ask me.. I always go for 'the shiny' one's; as I've suspected them to be "better"..
A horse can't be sick, you know, even if he wants to.
didn't anybody get the joke?
... unless you also make backups. A good jolt of electricity can fry all the HDs at once and without backups the data will be lost.
Ah, i use 2's and 3's If you saw a book filled with 2's and 3's, what would you think?
Make your computer faster: rm -rf
I have a ton of CDr's (everything I've ever created or downloaded) on the theory that when my hard drives go, I'll still have the orginal of whatever was on there. There's way too much to make new copies of, almost a 100 gig.
What's the bottom line? How long can I be sure my CDrs from 1997 will be of any use?
(Man, remember 1x burners?)
Sig not available, please try again later. If the problem persists, then the submitter is an idiot.
i only bought those for a while, they just looked so nice. No idea about their longevity tho, but i had some for at least 4-5 years and never had any problems. All maxells are cheap a reliable enough for me. Now, i wonder if they make them in dvds.
We should have been
So much more by now
Too dead inside
To even know the guilt
the weight of a Library of Congress with everything stored on clay tablets.
(We used to say that in former Soviet Russia when we went to library to read Natalie Portstone book).
Except for approximately 2% of business-critical or irreplacable data (pictures maybe), most of the stuff you have you don't need. You think you might need it, and you want to know that you have it, but you'll never need it. I know that everything, except my (backed up) downloaded music collection, and some other things, either I won't need or can replace free and easy. In 2 years, I guarantee the majority of what is on your computer now will be useless to you (other than stuff that can be easily replaced, like software).
I tend to keep things (like CDs) that I regard as archival in my freezer. Dark and cold... the reerse of light and heat.
A few years back I thought the same thing. Then the CDs I had just burned my entire mp3 collection onto under a month earler, so that I could make more space on my hard disk, stopped being readable. Better get to ripping...
the crossover between:
a) the time it takes to store an ever-increasing amount of data;
and
b) the ever-decreasing storage life expectancy (and ever-decreasing format obsolescence cycle).
It will then take longer to store the data than the storage lasts and your forward shifting methods will fail.
Only problem is, the message gets corrupted really, really fast. Witness the Religious Right in America. Or medieval Europe. Or the tail end of the Roman Empire.
"Hardly used" will not fetch you a better price for your brain.
When I was taking a discreet algebra course the prof got to talking about ecc codes used in cd's. To demonstrate how good they were he created a random 700mb file, took a md5 of it burned it to cdr and the made 8 equally spacede slashes along the top from hub to rim. He put it back in the drive and copyed the file back to the disk and got the same md5sum. I was very impressed
> I met a traveller from an antique land
> Who said: Two vast and trunkless legs of stone
> Stand in the desert. . . Near them, on the sand,
> Half sunk, a shattered visage lies, whose frown,
> And wrinkled lip, and sneer of cold command,
> Tell that its sculptor well those passions read
> Which yet survive, stamped on these lifeless things,
> The hand that mocked them and the heart that fed.
> And on the pedestal these words appear:
"Oz scratchum HTML in stone with stick thing"
Make-um website, for venture capital bling"
> Nothing beside remains. Round the decay
> Of that colossal wreck, boundless and bare
> The lone and level sands stretch far away.
With apologies to
> -- Percy Bysshe Shelley, Ozymandias, circa 2000.
I store all my data in FBI digital case files. The government will obviously never have a system in place that can read them, so I'm safe.
I'm Rick James with mod points biatch!
and ordering numbers, folks. not many websites of manufacturers tell you what they're using.
the only one I can find right now in three websites (verbatim, imation, tdk) is that tdk uses metal-stabilized cyanine dye in their CD-Rs. that would make them a "c5" sample, which is fairly resistant to stray UV, but temperature/humidity sensitive. to me, TDKs sound just a little bright, but it's not bright enough to be a car-only disk.
verbatim used to boast of using blue azochrome dye, which In The Beginning was prized by burners who wanted accurate audio. verbatim blue is still out there in the "digital vinyl" series at least. that would be an "S1" or "S3", who knows which, which has some issues with both temp/humidity as well as strong UV. Sounded good and neutral.
what I haven't seen is the richer, "tube" toned deep green of Sony and 3M 2x/4x disks of the late 90s. never knew what it was chemically, either. I'd order a case of them if I could find 'em. no "scatter-shatter" sound on those disks.
the only thing I've had issues with are budget CD-Rs with a barely-visible green coating to this point. they go away in a dark, double-shielded player in a console in the car, and have shelf life issues in the house as well. After two years, they wouldn't even pass the pre-record test of the burner. Never again.
but I can't buy for known permanance, despite NIST, because they don't call out whose disks they tested. Hope somebody consumer-oriented gets an idea from this, and beats 'em up with brand names attached. there's going to be somebody out there who has used junk disks forever and never lost a one sitting open under the cat hair on the window ledge, so anecdotal evidence is, uhhh, not reliable. even mine.
if this is supposed to be a new economy, how come they still want my old fashioned money?
For backups and archiving, I use hard drives, period.
I change hard drives every few years, since there's a constant attrition rate, anyhow. Plus they just keep getting BIGER and CHEAPER every year.
to me, optical media are for sending data to others, not for gathering dust.
if you go back far enough to have bought disks that said "100-year lifetime", you had that data.
of course, it was based on educated guesses based on short-term abuse testing and postulating that everybody would keep stuff between 65 and 70 Fahrenheit at 30-50% humidity in the dark. stored vertically in the jewel box, thank you, with all the original packaging paper stuff. unlabelled.
which happens noplace.
if this is supposed to be a new economy, how come they still want my old fashioned money?
Is the data really gone, or is it simply the reader that can no longer handle the tolerances? Are the dots truly gone, or just harder to read? It could be that archivists and the rest of us need more tolerant, but slower-reading devices for when we have flaky discs.
Really, the big advantage stone tablets have is huge amounts of redundancy, but a very small amount of actual data. DVDs could have multiple repetitions of the data on different parts of the disc for fault tolerance.
Ooh, a sarcasm detector. Oh, that's a real useful invention.
"I bring you these fifteen" [*fumble* - *smash*] "...er, Ten! Ten Commandments!"
"I'm not impatient. I just hate waiting." - My Dad
>can't buy for known permanance, despite NIST, because they don't call out whose disks they tested. Hope somebody consumer-oriented gets an idea from this, and beats 'em up with brand names attached.
I emailed all the authors asking exactly this question. I'm hoping to get a response. If I don't get one then you or I could file a FOIA request. They accept them via emial...
Not only that, but in Konqueror, you just click on a PDF link like any other, and it comes up in the window just like any other type of document. What's the big deal? What kind of crappy browser is the OP using that makes PDFs any more difficult to view than HTML?
Sure, 4 years ago a PDF link may have been a bit of a pain, but not any more.
To remove the opening of PDF documents in Firefox, that would be Tools/Options.../Downloads/Plug-Ins.../ then remove the check mark for PDF. At least I think so, the PDF entry isn't even there anymore on my system.
Being asked if you want to download or open a PDF document when you click on it might be nice, but I don't know if there is a way to do that.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
Useful info on a few of the manufacturers, thx. But seriously, are you really attempting to describe the performance of a digital storage medium with terms used to describe the way the stored data sounds? "bright", "good and neutral", "richer, 'tube' toned"?
The terms you use correlate to accuracy of reproduction of various frequency of audio. Audio stored on a CD (I"m not talking about CD with mp3 files on it) is stored as a sequence of samples... that is to say strictly as a time-domain function.
I can't think of any possible way that the performance of the medium could have an effect on the sound of the audio that could be remotely described by the terms you've used.
Personally, CD's are not usefull for data backup.
I have a box with an IDE RAID controller. Mirrored 120GB drives. I have software on my wife's windows box that backs it up to the RAID box each night, and I back up my box to it as well. So I have three copies of the data.
Apogee makes some quality media. Mastering studios tend to use them as masters.
There is software to recover from any error. I forget what it's called. It'll also do any real cd's you have.
It's really good, fixed up some old anime I had in rm on a bunch of old disks.
My understanding is that CD-RW and DVD-RW doesn't use an "organic" dye, but relies on some physical property of an alloy to determine a one/zero. Are CDRW even more or less susceptible to aging?
I recently starting going through some of my old CDR's and I noticed that 3 of my 4 CDROM drives had trouble reading a certain disc. I try a 4th drive (DVD+RW), and it reads it just fine. My guess is this means that the disc is starting to die, and now would be a good time to back it up again.
Is there any way to set up a 'RAID of DVDs' so that errors on one disk are fixed if not present on other disks?
___
It's the end of my comment as I know it and I feel fine.
Oh! THANK YOU! THANK YOU! I've got a few boxes of Kodak Gold Brand disks left. Nice to know that process was replicated by someone else.
Thanks!
___
It's the end of my comment as I know it and I feel fine.
Fortunately, the disc is still good! My NEC dual-layer DVD burner still reads the disc just fine. Unfortunately, it contains stuff I *never* listen to - mostly Eagles and Beatles and other old fogey songs.
This web page is from 2002 and may be obsolete, but it says that all Kodak media is silver/gold and has phthalocyanine dye: http://www.kodak.com/global/en/service/faqs/faq163 0.shtml
Guerre
Gold CD-R's are best for archival, but what about DVD's? Single or dual layer?
I have to backup a few large data sets (they're just over the size of a DVD, so I'll have to go dual layer). My plan so far is 3 sets of discs (one loaner, one on site backup, one off-site backup). Might also buy a hard drive and use that instead of one of the DVD sets. But, I've also had drives die if they're not running on a regular basis.
Or is my only option to find a used DLT drive somewhere?
I use Macs to up my productivity, so up yours Microsoft!
I have several old Kodak gold CDs recorded on an HP 4x burner about five years ago (about US$400 -- top of the line at the time) which have died. They were stored in an airtight plastic camera box with dessicant and rarely removed. Now the dead ones seem to have some sort of dull, milky film on the shiny surface. Cause of death is unknown. Their neighbors (the exact same gold discs in the same box) are still OK, but I am making backups while I can. You can't necessarily trust gold either :-(
Another good reason to store important things in the freezer is that the sealed metal box would be more likely to protect its contents in the event of a fire or natural disaster. Smart thinking.
Free Mac Mini - Help me
There are legend for cdr samples (e.g. s1 = azo), ....?
but wtf are the legend for dvdr???
wtf are those d1 d2 d3
Oh, and for you "Well just right-click on the text and click 'Follow Link'." people, tell me how to open a selected-text link containing extraneous Slashdot spaces in a new tab using Mozilla, or shut up.
Personally, CD's are not usefull for data backup.
Apparently, you don't believe in backups from what you write below.
I have a box with an IDE RAID controller. Mirrored 120GB drives. I have software on my wife's windows box that backs it up to the RAID box each night, and I back up my box to it as well. So I have three copies of the data.
So let's suppose that, unbeknownst to your wife, software on your her PC corrupts a file. That night, the corrupted file is automatically copied to the small (120GB) RAID array. Several months go by and your wife discovers that the file is corrupted. She goes to the RAID array and discovers that the file is corrupted there, too. Since hubby doesn't believe in archival backup of data, the file is irretrievably lost.
What if your home is burglarized? What if there is a fire? Since you have no archival backups, you can't go to the fire-safe or safe deposit box and get a copy of your valued files.
How would you feel if your bank told you that your account information was stored on a desktop PC, copied nightly to a server with RAID in the same physical location, and that there were no archival backups? No optical media. No DLT, LTO, or DDS4 tapes. Nothing. If it was my money, I'd have it out of that bank in an instant.
You're certainly doing a better job than most people, but don't kid yourself into believing that true, offline backups are unnecessary.
Bigger platters, bigger motors, the data is spaced further apart on the platters and the bits on the disk take up a larger area, thus using more magnetic particles.
New drives are much more delicate and the data is stored using a lot less area.
I personally have had several 30/40/80GB drives used as archive drives fail on me. All they did was sit on the shelf for 12-18 months without being spun up.
Be very careful.
Archivists make a mistake when they focus on the preservation of digital media instead of the preservation of the bits. Since bits can be copied over and over without degradation, they are potentially immortal. Academic disk-based storage systems like Oceanstore http://oceanstore.cs.berkeley.edu/ and commercial systems such as Centera and Permeon http://www.computerbanter.com/showthread.php?t=309 50 keep the bits safe using redundancy on multiple servers, geographic distribution, and continuous and automatic migration to new hardware. Just as in biology, the organism (storage cluster) lives much longer than the individual cells (servers).
I wonder what the longevity of DVD-RAMs is. I suspect it is much better than other forms of DVD as it has much better error correction, a diffecent kind of surface (oxygen I think) and you can put them in a caddy if you want, so that you keep them safe. It is also meant to be rewritten 100000 times. However, if you are worried about longevity then you need a magneto-optical disk, which basically needs both a magnetic field AND a laser (heat) to modify data. The chances of that happening unintentionally are really low. When CD's came out (early 80s) there was word that they would last max 15 years (alluminium oxydation). The ones I have from that time still work perfectly.
I had a friend tell me his store was bidding on a huge job to convert hundred of boxes of documents to PDF by scanning the documents. They were going to make CD-Rs with the PDFs on them.
They were then going to dispose of the paper documents via shredding.
This is an oil company with 20+ years of records.
The people he was bidding against were basically of the opinion of: "oh, these things last forever. don't worry about it."
Whereas I thought, "I think CD-Rs have a 10 year or so shelf life in darkness with low humidity."
I figured you would some optical character recognition to put into a keyword database and RAID servers and all kinds of good stuff. Not to mention making copies of the copies every X years.
Not to mention the fact that you would wonder if Cd-rom drives and Adobe Acrobat will be around in 10 or 20 years.
I kind of wonder how many people will get bitten by this issue.
I think this has been discussed before on slashdot that due to our digital world, ironically if there was some sort of global catastrophe there would be very little record of our civilization in 100 years.
This means that an errant or malicious program can overwrite files on your backup disk.
(Even with multiple copies of your backup, what happens when a trojan serruptitiously writes garbage to your older files on all of your copies while you are backing up your files?)
This can't happen with CD-Rs and CD-RWs (except to files that are currently being backed up), as long as you use a CD-ROM drive (instead of a CD-RW drive) to read them.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
...but the really annoying thing about CDs/DVDs, is that you have no idea that they have failed. You'll only notice when you try to recover. And I haven't found any program that'll let you burn a RAID - Redundant Array of Inexpensive Discs. If you want additional redundancy, you have to meddle around with creating PAR sets and distributing them yourself.
One small thing, which I've yet to see but maybe some slashdotter can point me to - is there any way, under windows, to automagically mirror a folder on one drive, to another folder (on another drive). I don't mean a full RAID1 of the entire disk, but the few 100mbs that are crucial. Sacrificing 160GB HDD space just for that seems like overkill.
Kjella
Live today, because you never know what tomorrow brings
I have encountered several people in the audio business describe the "Sound" of different types of CDs (as you do with "bright", "neutral", etc). However, I have yet to have a single one explain to me how a media type that simply describes waveforms through a binary series (1s and 0s) could possibly influence the sound produced, assuming the binary series is stored reliably in all of them. What impact would the media have on the waveforms? And WHY?
The only audible result from different brand of media, from what I understand, would be the vibration due to poor balancing, thickness, or other physical determinates of the vibrations of actual CD as it spins.
How do you store them? That makes a ton of difference. The golden rule: Always keep your discs away from heat and sunlight. Otherwise the dye will degrade much faster. Remember the dye is MADE to be light/heat sensitive. How else would you write to the disc? I can for the life of me not understand why R/RW-discs are sold with transparent jewelcases? Maybe to keep us re-burning our data every few years?
It was too much of a hassle to find the right one, so I transferred everything to HD. About 10 or so CD's were irrecoverably damaged. Some had faulty areas but were mostly readable.
Nowadays you should just buy a couple of 160+ gig HD's to store this kind of stuff. CD just does not have the capacity or ease of use or longevity, and DVD is not much better.
DVD drives in particular seem to be very picky about what they can read - I have 5 DVD drives only 2 of which read DVD+R's burned with HP NC8000, for example.
'Once scientists, even the dim-witted social scientists, get muzzled, the Western Civilization is finished.' - oldhack
Over the past year I've been migrating my archived data from CDRs to DVD-Rs. I copied several hundred CDRs back to a hard drive and the re-burned them. It was an education in which brands were good.
Everything yuo hear about Kodak gold CDRs is true. They're the best I've come across. Unbranded silver ones are crap. Princo, crap. RCA, crap-ish. "Gigastorage" brand cheapos stood up suprisingly well.
I tend to stick with Memorex now myself though.
i found an old disc labeled 'first one', and is the first non-coaster i burned with my hp 7100 cdwriter (which i still use, but no longer burns) ... the media is a hp 'c4432a', burned jan 5 1996 ... the data is still in tact, even trapped a few legacy virii in the confines of unscanned .zip files.
... ) but the data is still fine.
i'm curious what type of disc it is (dye), because it's 9 years old, and seen some of the harshest conditions i can imagine a cd-r would have to survive (cold damp basement, hot dry attic, caseless thrown around the desk
avg freaks out if i put the disc in the drive.
you can't have everything, where would you put it?
for any interested parties:
h tm l
http://www.cdmediaworld.com/hardware/cdrom/hp.s
is the c4432a page.
Name HP CD-R74 - C4403A
ATIP 97m 27s 55f
Factory Mitsui Toatsu Chemicals, Inc.
Dye Type Phthalocyanine (Type 5)
Color Top Gold
Color Label Blue/White with Gold Text
Color Bottom Gold
Capacity 650.85 MB (74:05:10 / LBA: 333235)
you can't have everything, where would you put it?
I've been in a bunch of places where the backups worked better than the restores...
And you jusy hit on the key point - 'cheap to medium grade CD media'.
There is some really cheap media out there. If you care about long term readability of the disk, use a brand name that you've had good luck with (or one that you know someone else has had good luck with). Use the cheap disks as temporary sneakernet options. Right now I've got two spindles of CDR media, one is a no-name, and the other is Verbatim DataLife+. If I care that I can still read the disk in a month, I use the Verbatim, otherwise I use the no-name.
Don't forget the part the the drive plays in readability. I've had disks not read in older/cheaper drives that will read fine in my Plextor.
Think Linus said: "real hackers don't do backups, they upload their stuff on FTP and let the rest of the world mirror it". Well, quite a good strategy :-)
Distributed online backup (with unison, for example) is a very convinient way for me to protect against hardware failure. It doesn't, however, protect against introducing errors into the file collection. "bit-rot" can be accounted for if you know if you actually changed some files (timestamps are good), but if you happend to zero a file which is the distibuted over the other backups, it is very good to have some rotating system, too, for the most valueable stuff. (and using CVS of course).
You must be the only person to have one of those. Most people tended to go through eight Caviars in one year. Go figure.
Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
Paper?? This is the digital age, son! You should type the ones and zeroes into a file and archive them on CDRs.
Make backups, use BitTorrent.
Like a moron, I traded a 100mhz dual trace Tektronix scope for the 133 meg drive. Now it sits on the floor in the closet. But guess what?
I'd gladly trade you my collection of antique hard drives (from 40GB on up) for that Tektronix scope, even if it doesn't work as long as the CRT is good.
"A single (S)ATA HDD requires a single (S)ATA connector. So in addition to that $100 drive you'll need a $5,000 box to put it in and to translate those several slow connections into Fibre or something else fast enough to make this idea reasonable"
I don't see your point at all. With LTO-3 your USD5K only gets you the drive, you still need to BUY a server to stick that drive to, and I'm sure you have the same problem of "slow connections" whatever that means (don't know what you're getting at).
Whereas so far most modern x86 servers have ATA connectors. If hot swap SATA becomes commonplace then you've already got your box - it's your server - I already see servers with hot swap SATA. So even though one LTO drive has faster transfer rates than one ATA HDD, you can stick 5 HDDs to 5 servers and back them up all at the same time, take the HDDs out and put them into archival storage. Whereas with the LTO solution - the 5 servers have to backup through that one server with the LTO3 drive.
If a server doesn't have a hotswap SATA maybe USB caddy HDD drives might not be too bad a solution at 30MB/sec.
"HDDs are really, really expensive solutions for any sort of archving, or for off-site storage. I can put a pack of 10 LTO-3 tapes in a box and ship it around the world for $20. "
You can ship HDDs around too.
And while you can ship your 10 LTO-3 tapes, if you need to read them you may wish to make sure there's a USD5K LTO-3 drive at the destination. Whereas finding a machine that can read SATA/ATA drives isn't as hard.
HDDs really expensive? Go do the figures yourself. AFAIK LTO3 tapes are 400GB for USD140. That's USD0.35/GB (I'm ignoring the compressed figures).
But they don't include a USD5000 drive.
Whereas ATA HDDs are 200GB for USD100. That's USD0.50/GB. They come with drive included.
As I mentioned in my previous post you need to have more than 83 tapes _per_ LTO3 drive, only then it starts getting cheaper than 200GB HDDs.
(AFAIK you only need 25 sets for the 6 week days, 4 weeks, 12 months, 3 years thing. 29 sets if 7 years.)
BUT if you start to need more than one LTO3 _drive_ before you hit 83 tapes then the LTO3 solution is more expensive. Remember - if you have one LTO3 drive at point A, and turns out you need another drive at point B (where you're shipping them to), then you now need more than 166 tapes, to be cheaper than HDDs.
Don't forget with 166 HDDs you can just stick them to 166 servers if you have that many servers. You don't have to look for a drive, since the "backup media" is a drive.
Also, I'm willing to bet the HDD prices are going to drop. With this scheme you don't get locked in to an expensive drive and media. Whereas if LTO3 media or drives become more expensive you're screwed. You still have to buy LTO-3 media and drives.
So far tape sure still seems like a con. Unless you're going to have hundreds of tapes per drive.
The tape drives would probably start chewing up tapes long before you have hundreds of tapes. So far the tape drive in my prev workplace started chewing up tapes.
I think you all misunderstand. As covered before, a little bit of entropy might give new interesting results. Just imagine your old family pictures with brand new colours (this might not be art though).
When you are sure of something, you probably are wrong (search for "Unskilled and Unaware of It").
Considering that there hasn't been a good song made since the 80s IMHO, I'll be more than happy to have your CD.
Use hex! It'll take a quarter of the time!
No doubt. I just today found 11 CDR's of various makes out of my garage today. They've been out there for a few years in the heat and cold. I was able to copy the contents of each one without any trouble.
Can anybody find out what the DVD sample D2 was?
An engineer who ran for Congress. http://herbrobinson.us
From the article:
Do not be mislead by the numbers presented--they have little relevance to how CD-Rs are typically stored.
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Maybe I'm blind, but I don't see a table discussing what the different DVD-R samples were made of. There's a nice table of which technology each CD-R was (S1 - S7) but nothing for D1-D3, which is the information I want...so I can buy a stack of D2's.
As someone else mentioned, use DGSI's gold MAM-A. They are clearly labeled on the spindle.
I suspect CD readers will be available for a loooooong time, because so much content is archived on them. It is likely that the 5-1/4" standard will last for at least 10s of years and everything will be backward compatible.
It would be nice if some DVD manufacturer would take it upon itself to describe its media's archival characteristics - then I think most companies would jump on the bandwagon.
-joseph
If one gets scratched, restore the ruined file (or restore the whole disk! it can't hurt!) and re-burn.
This has saved me many many many many many many many many times.
To take the idea even further, always buy two kinds of media (randomly, even). Burn 1 copy on one, and the other on the other. Now, if one media is better than the other, your data will survive as long as the best media, even though you did not know what that was at burntime.
Yes this costs some extra money. Believe me, I know. I've burned no less than 1800 cdrs (times two) and 450 DVD-Rs (times two). It's a small price to pay. and still cheaper than the harddrives (which I have 1390G of).
-Clio
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Blog: http://clintjcl.wordpress.com