Packrat or Archivist? [ was Adventures in GPG ]

[Ben Scott]

On 3/21/07, Tom Buskey <tom at buskey.name> wrote:
> DLTs are fragile.  They don't like to be dropped and like any magnetic
> media, they self erase.

  CDs don't like to be dropped, either, which I've demonstrated to
myself on several occasions.  :-(

  Most good mag tape, when properly stored, can sit about 30 years
before you need to regenerate it.  IBM can tell you this has been well
demonstrated for 9-track tapes.  DLT itself hasn't been around long
enough for that to be tested (yet), but I haven't heard any horror
stories (yet).

  Estimates for storage life of CD/DVD +/- R/RW range from 20 to 200
years, depending on flavor and who you ask.  However, unlike mag tape,
it hasn't been around long enough for that to be demonstrated.  CD-R
is just barely approaching 20 years old.

  I *have* heard horror stories about optical discs.  Manufacturing
defects have lead to problems after only a few years.  Apparently,
those giant spindles of unmarked media you can buy for ten cents a
disc suffer from poor quality control.  Whodathunkit?  ;-)

  Good quality optical media, properly stored (not just light --
temperature and humidity matter, too) is probably a pretty safe bet.

  I would be interested to see hard data of actual performance in this
area, though.  Not simulations in test chambers, but actual longevity.
 From an unbiased source, not a CD-R manufacturer.  With a decent
sample size.  Something like "FooCo has a library of 5000 CD-R discs,
over 2000 of which are at least ten years old.  They tested 50 discs,
and found no failures."

-- 
"One day I feel I'm ahead of the wheel / And the next it's rolling over me"
                                                  -- Rush, "Far Cry"