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."

Comments

Like having a baby

[Dancin_Santa]

Age 20 years in 3 months.

That's what waking up at 3:00 in the morning every day to take care of the kid does to you.

Re:Like having a baby

[eu_neke]

Wouldn't it be great if we could make the general readership of slashdot mature in the same manner?

This is an idea, albeit not perfect

[broothal]

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.

Re:This is an idea, albeit not perfect

[selderrr]

this reminds me of a very funny story some 35 years go.

My dad was a database guy avant-la-lettre : he used to catalogue his bibliografies and other stuff on small cards, and sort them in binders & carboard boxes all over his office.
These cards were kinda expensive though, and ordering them on univ budget took weeks. So when computer punchards started appearing, and programmers were trowing away hundreds of cards every day after compilation errors, my dad had found is never ending source of cards. So after a year or 2, his office was littered with punchcards with text written on the back.

Some time later, a collegue flew over from overseas for a congres. Upon seeing my dad's office and his insane collection of thousands of punchards, he went completely bananas "you've got everything on computer !! How splendid ! Could we please copy your archive to add to our own database ? "

My dad, being a complete computer illiterate was like "duh? sure, if you think it's of any help and if you return the cards"

So the collegue packed a few dozen boxes with cards and flew them to the US. Where they fed them into the poor mainframe....


I still giggle when I picture the problems their IT staff must have had trying to read the damd nonsense, and the look upon my fathers face "well offcourse the data is on those cards ! Didn't you guys turn them around and look ????" :-)

50 years is not enough

[Alain Williams]

• long-term archiving needs (i.e., 50 years and longer)

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?

Digital Short-comings

[locarecords.com]

The UK Parliament not so long ago debated the benefits of storage of Government documents and after heated arguments decided that digital was unproven and paper itself not good enough.. especially as they want records to last 500 years.

It shows that digital still has a long way to go compared to the current UK practice of printing on vellum... in other words goats skin !!!

Quote: "... we compare longevity of 250 or 500 years [of long-life paper] with the 1,500 years of vellum"

Re:Digital Short-comings

[njj]

One common criticism of the use of vellum is that of animal cruelty, although it's worth noting that the goatskin used is a by-product of the leather industry, and comes from goats that had already been slaughtered to make, say, shoes.

I was glad to hear that this latest attempt at pointless `modernisation' (for the sake of appearing `modern' rather than for any deeper and more sensible reasons) was defeated. Not least because it's really cool to be able to say ``This is actually an Act of Parliament from the 16th century, and that's actually Henry VIII's signature - not a photocopy, not a JPEG, but the real thing.''

A related matter concerns the increasing prevalence of digital photography. As this BBC News article explains, digital photography may cause problems for future generations of local or family historians. Proper (printed) photographs tend to get stored away in shoeboxes in attics, and are still more-or-less as legible after a hundred years as they were when they were taken. Whereas an entire collection of digital photographs can be wiped out by one hard-disk failure.

Or maybe in fifty years' time nobody'll know how to display a JPEG. Somewhere I've got a tape with the very first program I wrote, recorded on it. It was a simple bullseye game for the Video Genie II (a TRS80 clone) - it wasn't particularly sophisticated by general standards, but not at all bad for an eight-year-old kid. I have no means of retrieving it on any of the small menagerie of computers currently in my house.

Another, related, example: in the mid-1980s a (for the time, pretty damned impressive) multimedia project was launched - the Domesday Project. This was a laserdisc containing digital reproductions of the original 11th-century Domesday Book itself (a census survey of the entirety of England ordered by William I) together with (I think) the 1981 national census data. All very innovative (albeit rather a costly system) but ironically, 15 years on, the laserdiscs are not readable by current technology - but the original 900-odd-year-old Domesday Book itself still is.

I guess the point is that it's all very well saying ``this media is guaranteed to last for fifty years'' (although personally I'd be happier with something that'll last several hundred) but also you have to guarantee that the data format itself is going to remain readily decodeable. This is not a problem for 1000-year-old documents on vellum (as long as your Latin or Norman French is ok, and you've done a basic course in paleography).

nicholas

Re: CD decay rates

[some guy I know]

This recent article in The Register refers to a test by a Dutch magazine called PC Active.
They tested 30 different brands of CD that had been recorded only 20 months earlier.

"Several data CDs developed serious errors, or became virtually unreadable."

Here is a picture of one of the CDs.
The red area can no longer be read.

This is pretty hideous.
I use CDs for archival storage.
It looks like it will become necessary to copy everything to new media every year or so, lest it become lost, forever lost, never to be seen again by the eys of mortal man.
It's very annoying.

This problem has already been solved

[treat]

If you're a sysadmin, this problem has already been solved. RAIDed hard drives, always on, read occasionally to check for errors, and drives replaced as they fail. Replace the drives with new models every so often (or as they fail perhaps). Replace the controller and system it is attached to as necessary.

That is to say, that no digital storage that exists outside of a lab is suitable for long-term archival. Luckily, digital data being so easily copied (how easily people forget this!) makes this an easy problem to ignore. If you're developing new types of media, great. Otherwise, there is only one practical solution.

Yes, "my" solution - the solution used by anyone who has digital data they want to store long-term - requires someone to babysit the data. Sorry, most things in this world need some kind of human maintenance.

If you're storing the data on hard drives attached to a working computer, you can mirror the data on the other side of the world to protect it against any catastrophe that humans will survive.

If you don't care about a practical solution that has by far the highest chances of success, feel free to speculate about how long CDs will last based on completely invalid lab testing. (Accelerated aging? Hah! How can they possibly account for every variable?) If you truly care about your data, keep it online and make sure someone is around to maintain the system. If you want something less, it's because you don't actually care about the data that much.

Gold video disk with 296,000 year lifespan?

[adeyadey]

In 296,000 years Voyager-2 will pass Sirius... Do you think the gold video disc on-board will still be readable? :-)

My findings

[Mxyzptlk]

This is quite interesting - I'm looking into CD archiving quality right now, because I have to transfer my grandmother's story of her life from ordinary tapes to something more persistent.

Some things I've discovered so far are:

• The swedish national archive recommends Kodak Gold Pro for archiving purposes. However, Kodak seems to have stopped selling them...
• Gold CDs are better than silver CDs. The worst kind of CDs are the ones that you can see right through, if you hold them to a lamp.
• You should store your CDs in their original packaging, if available. That is: store them in a hard plastic package, and avoid soft paper or plastic. Store them upright, in 22% humidity and 5 C (66 F).
• Avoid humidity and light as the plague - even a couple of minutes of sunlight can have a great effect. If you are really paranoid, then you should use clean cotton gloves when you are touching your CDs. Of course, scratches, finger prints as such are not good...
• You should use CDs with less storage space, because the bigger the room each bit has, the less risk is it that that bit can be destroyed.
• If you must write something on the CD, then write as near the center hole as possible, and use you smallest handwriting. The color of the pen can actually affect the reading capability of the data, although the data is on the opposite side of your text.

The biggest problems seems to be that the CDs come and go, so it can be difficult to get the tested products. The tests that has been done has used "accelerated aging", which is just a simulation. That is, there is no real experience in aging CDs.

My advice would be to store valuable information on as many different formats as possible. Continually monitor the quality of these, and transfer to new backups when they start to degrade too much.

Hope this helps!

Copying from generation to generation doesn't cut

[OzPeter]

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?