Slashdot Mirror
CDs, DVDs Eyed For Long-Term Archival Use
Alien54 writes "Computer scientists at the National Institute of Standards and Technology (NIST) are launching an effort to develop specifications for 'archival quality' CD and DVD media that agencies could use to ensure the procurement of sufficiently robust media for their long-term archiving needs (i.e., 50 years and longer). See the press release at the NIST site." The research involves "...enclosed chambers that use temperature and humidity changes to artificially age the media some 20 years in only six weeks."
It's cool to create media that can hold information for an extended period of time. But - do not forget that you need to have a device that can read the media. I've saved some of my earliest work from the 70's on a paper strip with holes in it, and from the 80's on a 12" floppy disk. Both look like mint condition, and I'm sure they work. But - I haven't got any hardware that can read them.
So - if you plan to store digital information for decades, you need to store the player as well. That means, you need to make hardware that will work after, say, 100 years. This makes me think if we should strive after something that's human readable (microfilm or plain old paper) instead of something that require a computer. This is by far an easy problem to solve. My humble suggestion is to save information on todays media and prepare to copy it to a new media every 10 years.
50 years is not long, 500 years is what we should be talking about.
Books, if looked after properly, last for centuries. OK: many modern paperbacks are printed on paper that has not been properly stabilised (still contain acid), but there are plenty of very old books.
In case you think that I am over the top: have you never looked at an old family album with pictures going back to the start of the last century? What will future generations think of us if none of that sort of material survives because we had the lack of foresight to put it onto good media?
For a start.
A typical backup tape will handle 120Gb to 200Gb these days.
Then you have the problem with getting hardware which will read the disks in 20 years or 50 years.
The real solution to archiving is the ability to move to new formats as they appear and become cheaper than the existing technology, it's an ongoing process, not a product. The hardware itself should be irrelevant.
Government of the people, by corporate executives, for corporate profits.
The software for HP WORM drives used on Solaris requires proprietary kernel drivers that have a license tied to the hostid of the machine. Good luck.
Tape. Back it up onto tape. Useless as an everyday access medium, great at archiving. Also, try to keep multiple redundant copies.
Well, it interests me for similar reasons. The site you're looking at there contains photos and some smallish video. They are backed up in a copy of the site at home, backed up in a copy of the individual media files on a seperate machine, backed up to DV tape (not the best, but better than nothing) and also backed up by my co-lo ISP nightly.
So...make at least three copies (live, on-site, offsite) and try to get at least one of those copies onto stable removable media, such as tape.
One last thing - make sure you keep the hardware and software around to read it. About twelve years ago I was involved in a rushed-job project to read some tapes and format the data. The reason? My employer at the time had brilliantly decided that they didn't need those old tape-reading machines that didn't connect to anything, and threw them away. Of course, when the contract came in for processing that tape format, as it did year after year, they suddenly found themselves unable to do a thing with it.
Cheers,
Ian
I understand that removable media always run a much greater risk of going bad as they're exhibited to all sorts of possibly harmful effects. However, I'd really like to see "CD-like" discs that last at least for around 20 years to give us plenty of time to at least transfer them to more modern media when they arrive. The problem right now is pretty bad since the media degrades much quicker than new technology arrives, with CD's already becoming unreadable when we haven't even fully made the switch to DVD's yet. I'm sure there are other perhaps more reliable removable media available, but they aren't as widely accepted, and I find the problem actually rather silly since reliability on removable media should come as a top priority, with those often being used exactly for storing old data not immediately needed on a hard drive -- as an archival media.
:-P
If this test will lead to an insight in making more reliable CD's or DVD's, where those can be somehow certified with a special "Archival Quality" tag, I'm sure they would sell a lot even to a greater price. I'd completely switch to them at least, since I burn CD's to make them last for a longer time than a year or two. Switching to tapes or something like that isn't very useful, since everyone I might bring my CD's to would need a tape drive.
Beware: In C++, your friends can see your privates!
I keep my data on burned CDs precisely because I care about it. A CD-R has one extremely important property that magnetic media doesn't have--it's read only, which means you can't accidentally delete it all when you're trying to restore it.
I used to work for a well known enterprise backup company. They had statistics around that said that the primary cause of data loss (by far) is operator error, second is software failure, last is hardware failure.
I used to think that online disk was the right way to go for important data, but any box that is on and on the Internet can be hacked, or someone can trip on the power cord, spill coffee on it, or decide that the backup server would make a really good Quake server. Given that, a write-only media stored a thousand miles away in a vault has some real advantages.
Now, if only we could get some media that would last more than two weeks, we'd be all set.
I see a lot of people saying that the short CD lifespan is not a problem .. you just copy from one generation of media to the next as you approach the optimum time.
Well that doesn't really cut it for two main reasons
1/ You have now decided that the only information you will hand down to the future is that the stuff that you care about now. As soon as you stop caring about that data, or your descendants stop caring, then that data will lost.
2/ It will only need a skip of roughly 2 generations of technology before you won't be able to recover any digital data that you (or someone else) accidently re-discovers.
If this doesn't seem important, look at what historians and archeologists are finding/learning from poking around things that have survived millenia, compared with the despair of knowing what huge gaps exists from records/items that have been irretrievably lost.
So how do you want to judge the concept of "archival"? As something that is accessible as long as the item is whole, or as something that requires active intervention to maintain its integrity?
I am Slashdot. Are you Slashdot as well?
30 years is considered good enough for day to day use, nowadays. But as a teacher of mine keeps repeating: "we have more problems retrieving data from the 1970's than from the beginnig of this century" Indeed, our future generation will only see a gap...
Many people have talked about older methods of storage as the gold standard. Paper, vellum, papryrus, clay tablets - some documents written on these media have survived thousands of years.
BUT, they have not survived that amount of time without degradation. The reason we can still read them is because of their low information density. Documents can fade - a 1 inch square portion of a document could flake away, leaving the original text still readable. Why? Because 1 square inch of most documents doesn't contain all that much information.
As physical objects I suspect that quality CDs or DVDs would degrade less over 1000 years than just about any of the other media I've previously mentionned. The problem is that we are trying to cram so much data onto them that even the slightest bit of degradation leads to data loss.
So what's the answer? Massive redundancy. Replicate data in 100 different ways across the surfaces of the CD or DVD - this might dramatically decrease the storage capacity, but even 10 MB on the surface area of a CD is a massive improvement over the storage density of vellum. Now you have a chance of lasting 1000 years. Even if the CD is shattered and all some future archeologist can find is a shard, there is a good chance that the entire data set is contained within that shard, perhaps even multiple copies.
Even further, one could imagine using file formats that are resistant to file errors, perhaps uncompressed raster images. Easy for future scientists to decode, and wonderfully resistant to degradation. This is just another way to decrease density.
-josh
Why look for a 50 year solution, when in 20 years the archives will be stored on more efficient media, just like mp3's.
But what are you going to store your mp3's on? CDR's? DVD-r's? Hard drives? Flash memory? We don't know much about the long-term reliability of any of those formats, although I don't feel particularly rosy about archivability prospects for any of them.
OtakuBooty.com: Smart, funny, sexy nerds.
> Only if you're a crappy parent.
Anyone who has had a kid with colic knows you're
full of crap. It's a totally different experience
and I agree with the first poster, you feel old
quick.