Long-term backup storage media

Hard Drives. Space is dirt cheap these days, you can grab a few TB worth of internal hard drives at a fairly low price. Even external hard drives aren't too expensive.

"Rumors say CDs and DVDs won't remember
your data longer than ten years.

You just said it: RUMOURS! :)

The Optical Storage Technology
Association (OSTA) has published the
following longevity estimates for
recordable optical media:

Manufacturers' estimated recorded life
span.

CD-R: 50-200 years

CD-RW: 20-100 years

DVD+R: 30-100 years

DVD+RW: 30 years

BD-R 50+ years

So, chances are that you may not live long enough to prove these estimates wrong! :)

Now compare that to the average lifespan of a platter hard disk (2-10 years). Optical media win that contest hands down.

And then there is the good old stone tablet which will last a couple of thousand years. But the data density of 0.001 kbit/kg is a bit of a showstopper. :P

But in IT, the Cranberry Diamondisc DVD is considered to be the Holy Grail of long term storage, they boast a life span 1000 (one thousand) years. Of course it requires special hardware to burn these discs."

"From http://www.superwarehouse.com/HP_5.2_GB_Magneto_Optical_Disk/88146J/p/54344:

HP magneto-optical rewritable
cartridges allow virtually unlimited
read/write cycles, making them the
ideal choice for data management in
information-intensive environments. HP
write-once cartridges are designed for
permanent storage of data that can't
be altered or erased. Both disk
formats have an archival life of 100
years..."

Paper backups using an efficient encoding scheme also remain an option. It is not handy and takes a lot of space, but it is robust and long-lasting.

"I think the question that must be asked is ""how long-term is long-term""?

Quality paper is probably the most efficient low-end long-term storage currently known(300+ years).

But if you're looking to archive records in the event of nuclear blast, you might try etchings on metal in a can in a cave.

But if you want to store company records for 50 years, hard disks disconnected and stored in a vibration-less environment together with paper documents on the interface & data formats is not a bad plan.

But if you want to publish historical-class data for the next 200 years, ie, you're investigating for a library or similar institution, you want to make sure that the information is usable when we go to The Hypernet, so you might be investigating a redundant array of cloud data storage centers from different companies with a common query-able interface published on the current Internet.

But if you want to archive historical-class data, you want something that is probably similar to a ROM-style hard disk. (I'm taking a guess that those exist for long-term archive storage).

But are you storing text? video? pictures? binaries? Each of those has different information characteristics and can be stored a little differently.

There's no 'right' answer here until you narrow your focus a bit."