28 Jul
2004
28 Jul
'04
7:18 a.m.
From: "Pete Turnbull"
<pete(a)dunnington.u-net.com>
On Jul 28, 12:11, Joe R. wrote:
Hi
This would put the per unit failure higher than even floppies.
I have floppies that are in the 25 year range and still read
correctly ( not used regularly for archiving ). The only large
issue I've seen on floppies is those higher quality ones with
the liners. The adhesive used to attach the liners tended to
bleed through the liners and get on the disk. I do keep things
stored in areas that rarely see more than 75F or more than
75% humidity.
Dwight
The problem is that AFIK no one has found ANY
CD disks that are
reliable. Several people that have been interviewed in national
publications explictly pointed out that they bought top quality disks
but
they were still unreliable. In fact, it
didn't appear that there was
much
difference between the cheap ones and the
expensive ones.
The other day I came across a table from a report showing the relative
longevity of data on various media (DLT, CD-R, etc) at a variety of
temperatures and humidities. I'll try and find it again and post some
of the results. Some of you might be shocked. For example, a CD-R
with an expected lifetime of something like 25 years (if I'm not
misremembering the highest figure) under ideal conditions has a
lifetime of only several *months* at higher temperatures (upper 20s C,
that would be 80s F) and humidity. DLTs fared much much better.
I have some CDs that were bought about 8 years ago because they were
supposedly good quality, and burned in a highly-rated burner. Out of
the first batch of ten, 4 are now unreadable or give multiple errors.
--
Pete Peter Turnbull
Network Manager
University of York