On 1/17/2023 7:54 AM, Paul Koning via cctalk wrote:
On Jan 16, 2023, at 9:48 PM, Fred Cisin via cctalk <cctalk@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.
Not SSD, that's for sure. The fact those are becoming the predominant storage
medium is a bit of a concern for long term storage, because SSD is entirely
unfit for that job. Apparently they are ok when powered because the firmware
will refresh the bits from time to time, but you can't put an SSD on the shelf
and still expect its data to be good a decade later, as you can with hard
drives.
With hard drives you have to worry about mechanical faults, of course. I
wonder if there are any long term storage issues with the bearings.
My understanding is that it is a good idea to plug the hard drives in
once in a while just to get them rotating for a moment to keep the
bearings lubricated or whatever.
So far, so good on all my backups but I am a bit bad about doing that.
I use 2 backups at least but some of the more important stuff I use 3.
There used to be a program that would read the disk and write the bits
back to freshen up their magnetic domains.
That might have been "Spinwriter" ?
boB
Most likely, the biggest issue with old storage devices is the loss of the device to
connect them to, and/or the loss of the code that reads them. To pick one example, I
have an 1990s era Dell laptop that no longer passes POST (it gives a "beep
code" failure that I haven't been able to cure). I would like to get whatever is on
its hard disk, but that has a proprietary interface as far as I can tell and I have
nothing to plug it into.
I have an RM03 pack somewhere. There probably are a few places left that could
read it. If it were an RA60 pack it would be a whole lot more problematic, I
suspect. Without an old drive, how would you recover the data? Spin table?
Perhaps, if you can find, or reverse engineer, the format.
The Long Now foundation has done work on the question of storing data in a way that can
still be deciphered a millennium from now. It's not a simple question. Some SF writers
have wrapped stories around the question (James P. Hogan did it several times -- Echoes
of an Alien Sky, Inherit the Stars, and much earlier (1957) there was H. Beam Piper
"Omnilingual").
Early storage devices are less problematic than newer ones, given the more and
more complex coding used. Never mind intentional encryption; just the high
density codes with interleaving and ECC and all that would be somewhat akin to
encryption when examined with a future archeologist. Imagine, for example, an
archeologist 5 centures from now trying to make sense out of a box full of SATA
interface hard drives, full of documents in PDF, JPG, or MP4 format.
paul
