[PLUG] long-term data storage

[Ed Sawicki]

On Wed, 2003-02-26 at 21:07, Carla Schroder wrote:
> Is there any medium besides paper that you trust for long-term data storage? 
> Seems like looking beyond five years gets iffy. What about 10-30 years? Which 
> still isn't that long, compared to books and magazines. 
> 
> Seems to me any magnetic media, such as tape and hard drives, are inherently 
> risky. Optical disks might last longer, assuming the means to read them 
> survives. I've heard more than one passionate rant about "CDROMs will 
> spontaneously delaminate, mark my words, and then you'll be sorry!" I have 
> five-year old CDROMs that still work, my precious Quake and DOOM cds.

I studied this issue a while back for a customer. I did
some informal testing as well. I had an extensive library
of diskettes that was indexed with a database so I knew
when the diskette was placed in the library. I noticed
that errors started occurring in diskettes that were over
6 years old and by 10 years the failure rate was nearly
50 percent. At 15 years, the majority of the diskettes
were unreadable.

My old 9 track tapes were still readable after more than
10 years - just in time for them to become obsolete.
I have spools of punched paper tape whose holes haven't
yet grown in, so they're still readable but I sold my last
paper tape reader a few years ago.

I now archive to optical media and I've put two new CD-ROM
drives in storage for the future. My archives tend to be
cumulative - I'm backing up the same old data along with the
new data simultaneously, so the age of the media is not as
critical. If I were not able to do that, I'd make copies of
my archives every decade or so.

-- 
Ed Sawicki <ed at alcpress.com>
ALC