On 11/4/23 21:05, gene heskett wrote:
On 11/4/23 23:15, David Christensen wrote:
On 11/4/23 17:55, gene heskett wrote:
FWIW the rw's I have and that continue to work, are Sony DVD+RW, well
over 5 years old now. I understand there is a DVD-RW but I've no
experience with them. Today my objection is the size. In comparison
to a system driving 3d printers with gcode from Cura-5.4 that is not
rolled up into subroutine loops, I have some of the more complex and
large parts part files that will not fit on a dvd. So it simply
impractical for me to back up to a measly 4.7Gig dvd.
That's why they invented Blu-ray:
https://en.wikipedia.org/wiki/Blu-ray
25 GB (single-layer)
50, 66 GB (dual-layer)
100, 128 GB (BDXL)
Shudder. Anything mechanical can be destroyed by a smoke particle 100x
to small to be seen with a good eye. I am a CET & Electronics in general
I understand the physics of, and in electronics the only thing moving is
a few electrons here or there. As long as the voltage does not force an
electron thru the oxide layer that is the capacitors insulation, forming
a leakage path that avalanches thru the oxide film and essentially
destroys the device, there is no physical reason that it will not
continue to do its jobs for hundreds or thousands of years. It will be
external environmental effects that will eventually reach the chip and
byproducts of the humidity let in by the breach of the package sealing
that finally destroys it.
The size of a bit that is detectable on a disk is determined by the
wavelegth of the light reading that bit, cd's were designed with the IR
lasers of the day, which emmit light in the 1100 nanometer range. Far
infrared IOW. DVD's were made possible with a shorter visible light
laser, then blue rays got that down to abut 400 nanometers. The next gen
of those will have a uv laser but we'll have to invent it first. But
part of that problem is that decent optical glass for the lenses does
not pass UV to a usable amount. Plastic lets it blast on thru but can we
make plastic lenses that precisely for the price bleeding edge users
will pay? IDK.
Interesting tangent.
The point I was trying to make is that proper disaster preparedness
involves defenses in depth. AFAIK your data and your backups are on the
same computer and you have no other recent backups or archives. If
true, then, as you already know, the computer is a single point of
failure that could destroy both data and backups.
And, now you are touching HBA's, touching drives, and issuing root
commands that are in direct proximity to your data and backups. As you
already know, human error is the most common failure mode. I am worried
that you are going to make a mistake and suffer a data disaster (partial
or total). That is why I suggested that you give the Asus a rest and
build a backup server now. If you then trash the Asus, recovery will be
possible. A duplicate set of backups is wise in case something happens
to the primary backups (notably, human error during recovery).
David
