I had to do something similar a couple of years back. But after exhaustive
research the best practices are very expensive and require additional
personnel to make sure all the steps are followed.

First: You need a starting media, 12 years ago it was 9-track tape, which
under the best conditions had a life span of 3-5 years, before sticktion
almost makes them unusable. Now it is probably a linear tape with a proven
record and enough market share to last 10 years or to at least get service
on a drive in 10 years if you need it for migration purposes. Most have a
"marketed" life span of about 30 years, which is a best guess to migrate
after 10 - 15 if they are stored in a pristine environment.

Second: A perfect environment for storage. What is perfect ? Were the tapes
made in a perfect environment? Yes and No. Ever get a bad lot of DLTs or
LTOs? Humidity fluctuations, temperature fluctuations. Best idea is to make
duplicate or triplicate tapes that are all stored in different locations by
either different companies or different corporate sites with all the
environmental controls.

Third: Hardware. At least three, or more depending on the quantity of tapes,
of whatever tape drives the data was written with. All must have maintenance
until you no longer have the media. We had 10 years of 9-track tapes, 9
years ago, Close to 10,000 tapes. In an attempt to migrate the data, we had
to keep our old tu78 tape drives on maintenance, $479.00 a month X 4, after
sticktion caused 95 tape breaks and almost 100 maintenance calls for damaged
r/w heads, our VP deemed it a waste and we crossed our fingers as our
retention policy has slowly come up. I can't wait to see what we will be in
store for when we are performing our first migration of ES data from DAT,
CD, DLT 1 and 3490 cartridges.

Fourth: Personnel that will know what to with the data once it is restored.

Last but not least: A library system to keep track of it all, which will
have to be upgraded, maintained and probably change companies every 5 - 7
years. How many media library products will still be around in 2052 ? Backup
Exec, Netbackup, Networker, TSM ...

It's not impossible but it requires due diligence on the part of the Media
Librarian.

Good luck.
Duane Ochs
Quad/Graphics Inc.
414.566.2375