The only answer that anyone can provide is redundancy. Keep 2 or 3 copies of everything
on seperate external drives. Every 3 to 5 years buy new drives and transfer the data to
them. Or just run checkdisk twice a year and wait for 1 drive to start popping errors.
Replace it. Wait for other to fail. Then replace it.
No one can tell you how long a single media will last as you pointed out. You can only
rely on making periodic reliable backups.
There's also the issue of practicality. Burning disks is laborious. If they're big
disks, it's not as laborious (I guess). Much maintenance and replacement of hard
drives can be done unattended. But be careful with that as Windows gets lazy and will quit
if you try to transfer too much data at a single time.
Cost wise I don't think magnetic backups is much different from any other. On
Monday, January 16, 2023, 09:48:17 PM EST, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
What about M-DISC DVDs and BluRays? Archival grade,
not susceptible
to magnetism or EMP. I think BluRay discs are made of a harder material than DVDs
and don’t scratch as easily.
On Tue, 17 Jan 2023, Chris via cctalk wrote:
Don't know, don't care. If we're being
attacked by nuclear bombs of any
stripe, I have far more humongous things to worry about then what's on
my hard drives. I suppose if you were wring a book and wanted to back
that up to an optical disk, go for it.
I care, and would like to know more.
Even without nuclear bombs, which I stopped worrying about 60 years ago, I
have occasionally had to deal with damaged data, from causes much more
mundane than EMPs.
I have had magnetic, AND optical media that have "gone bad".
I am interested in whatever media are more likely to still be readable in
a few decades.
M-Disc claims 100 year life, but, obviously, no M-Disc has lasted that
long, and they are making promises based on what they THINK will happen.
M-Disc BDXL is currently available in 100GB per platter.
--
Grumpy Ol' Fred cisin(a)xenosoft.com