how to measure microsd wear

[Ian Lepore]

On Sat, 2017-01-21 at 15:46 +0000, tech-lists wrote:
> Hello list,
> 
> How would one measure microsd wear? Is there a utility like
> smartmontools (I think this only works for regular hard drives) but
> for
> microsd?
> 
> many thanks,

There is basically no way to see what's going on in the flash array of
an sdcard.  The microcontrollers in modern sd cards have complex wear-
leveling algorithms which are completely transparent to the outside
world.

On the plus side, most of what you see in the way of warnings and scare
stories about wearing out sd cards is pure BS.  I've got systems here
that have been running for literally years on the same sdcard, and that
card is being used for swap, and routine data storage like syslog (on
an embedded system that logs status and progress pretty much
continuously 24x7 for years).  I've seen a few sd cards die over the
years, but I've never been able to say it was because of how much was
written to them (indeed, the dead ones I've got weren't in service long
before they died).

-- Ian