XPost: comp.os.linux.misc

On 8/13/23 3:33 AM, The Natural Philosopher wrote:

On 13/08/2023 01:40, Computer Nerd Kev wrote:

At the point where you _need_ something to work for a decade, it's
probably worth looking at industrial SD cards rather than
off-the-shelf ones. These are commonly characterised by using SLC
flash, which trades storage capacity for more write cycles.

NAND flash types:
https://www.kingston.com/en/blog/pc-performance/difference-between-slc-mlc-tlc-3d-nand


The datasheet for this SLC SD card describes the controller's
reliability features (including wear levelling):
https://docs.rs-online.com/29d1/0900766b815d5fe1.pdf
(pages 11 & 12)

Here's sales info from another industrial SD card manufacturer, who
elsewhere also advertise SD cards with an "advanced wear levelling
algorithm":
https://www.atpinc.com/blog/industrial-sd-cards-factors-requirements-to-consider


I'm not sure whether the industrial SD card controllers really do
much more for increasing longevity in a read-only application
though.

Indeed. It does seem that with the price of computing power falling so massively, there is little reason *not* to add wear levelling to SD
cards. Which ultimately renders them as reliable as any other NAND based flash device.

My interest is, as always, to understand just enough to get the job
done, which in this case means I want about 10-15 years of reliable
operation on a 24x7 basis.

Having noted that in normal operation as far as I have built it, the
unit is not accessing its SD card AT ALL apart from a daily write to
some logs, I think that there I will stop.

There happens to be a sufficiency of RAM to regard the SD card
essentially as EAROM.

That will do nicely.

I wrote a multi-channel environmental monitor for "field"
use a few years ago. It took 12 samples per hour. Does not
sound like much, but it adds up. The device also HAD to
store a lot of high/low and random params which could
change every sample.

For that I chose I2C FRAM. No wait states, effectively
unlimited re-writes. Better than SD or on-chip EEPROM.

This is NOT a solution for jamming an entire OS into
unless it's DOS 2.x but you (and hopefully the distro
writers) do your best to shift all the OS stuff into
RAM and kinda hope for the best. The params in the FRAM
take care of reboots, save "the state".

--- SoupGate-Win32 v1.05
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XPost: comp.os.linux.misc

In comp.sys.raspberry-pi Jörg Lorenz <hugybear@gmx.ch> wrote:

Am 12.08.23 um 11:55 schrieb The Natural Philosopher:

On 12/08/2023 10:10, Jörg Lorenz wrote:

Am 12.08.23 um 09:43 schrieb Richard Kettlewell:

At any rate, chatter about the longevity characteristics of storage
devices seems on topic here to me.

This is a general hardware question and not of any relevance to Linux in >>> particular.

If you look at the headers, assuming you can read, you will see that its
cross posted to comp.sys.raspberry-pi,

comp.os.linux.misc

Stop this X-posting! Get it?

The horse is dead. Quit beating it. If you find a topic annoying, killfile it. (You do know how to use your newsreader's killfile facility, right?)

FWIW, I find you more annoying than this topic, so...

** PLONK ***

--
_/_
/ v \ Scott Alfter (remove the obvious to send mail)
(IIGS( https://alfter.us/ Top-posting!
\_^_/ >What's the most annoying thing on Usenet?

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On Sat, 12 Aug 2023 12:41:31 +0200, in <ub7nkr$bgb$1@solani.org>, J÷rg
Lorenz <hugybear@gmx.ch> wrote:

Am 12.08.23 um 12:26 schrieb Pancho:

Looking at previous postings, it seems about average "on topic" for
comp.os.linux.misc, it is 100% on topic for comp.sys.raspberry-pi.

I'm interested.

If you want to criticise, there is loads of other shit that we discuss
that isn't on topic.

Discussions with fake identities are futile.
The Natural Philosopher <tnp@invalid.invalid>

After many years I've discovered that those complaining about a non de
plume vs a real name, and esp a working email address, are only trolls
looking for info to allow harassing the poster via other means.
--
Jim H

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