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Re: FFSv2 log option with SD card



On Sat, Feb 22, 2020 at 08:24:18AM +0000, Sad Clouds wrote:
> On Sat, 22 Feb 2020 11:37:35 +1100
> MJ <mafsys1234%gmail.com@localhost> wrote:
> 
> > 
> > On 22/02/2020 4:28 am, Sad Clouds wrote:
> > > Hi, is it advisable to NOT enable log option for FFSv2 that resides
> > > on SD card due to flash memory wearing out in those regions, or
> > > does it make no practical difference because of built-in wear
> > > levelling?
> > 
> > 
> > How long's a piece of string?
> > 
> > Wear levelling just evens out the wear... surprise. It doesn't
> > account for the overall wear.
> 
> Well the SD card contains a general purpose file system, so I'm
> expecting some wear on it as data is written over time (normal desktop
> computer use). I wasn't sure if FFSv2 logging would significantly
> shorten the life span. But I'm guessing it may not be such a big issue
> for quite a few years.

From what I have gathered from infos taken here and there, it will
depend on how much percentage the data is occupying on the SD card. If
there is enough empty room on the SD card, the card is optimized so that
new data is written "elsewhere" so that new writes impact other sectors.
The much you have not used sectors, the less the sectors are overwritten
and thus the longer the card will survive.

The error is taking a card that is too small and fits too closely the
amount of data being retained.

FWIW,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
                       http://www.sbfa.fr/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89  250D 52B1 AE95 6006 F40C


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