On 10/30/2019 4:01 PM, Björn Lundin wrote:
> Den 2019-10-30 kl. 02:25, skrev Knute Johnson:
>> Following a discussion on another thread about the life limits of an
>> SDCard I thought I would write a program to write one to death and see
>> just how long it lasts.
>>
>
>
> looking in the code
>          Arrays.fill(ones,(byte)1);
>          Arrays.fill(zeros,(byte)0);
>
> should that not be
>           Arrays.fill(ones,(byte)255);
>
> if all bits should be 1?
> Or am I thinking wrong layer here?

I don't know.  If as the other fellow said it erases the block before it
is written to and that erase is ones, does writing 1 which has 7 zero
bits cause more wear?  There are a lot of unkowns here.

> And if the filesysem is the wrong layer,
> perhaps sticking the card in a pc and use
> a script fiddling with dd is better - it s on block level

The basic idea is to write the SD card to death at some future point
taking a measurement to get an estimate of real use card life.  That's
why I am writing files.

knute...

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