[OT] Testing an SD card

[Volker Wysk]

Am Freitag, 26. August 2016, 18:08:12 CEST schrieb Josef Wolf:
> On Fri, Aug 19, 2016 at 06:50:00AM +0200, Volker Wysk wrote:
> > I've let your script run over night, and it still didn't finish. The SD
> > card is 64 GB large.
> > 
> > The output in the (small) part which is visible in the xterm, and which
> > can be scrolled back, didn't contain any error messages.
> 
> That there are no errors doesn't mean anything AS LONG AS IT HAS NOT
> FINISHED.
> 
> You need to undestand that there are two passes:
> 
> First pass will fill the SD with random data. NO error detection is done
> during this pass
> 
> Second pass verifies taht what was written can be read back. Only when the
> first pass is finished, you can tell whether there were any errors.
> 
> During operation, there is progress output:
> - w=first, r=second pass.
> - amount of read/written data
> - duration of the pass
> 
> From this output, you can deduce how long it will run.

My smartphone had - sometimes - produced funny errors, which seemed to point 
to a faulty SD card. I've replaced it with a new one. Now everything works 
again. They aren't that expensive. No need to worry much about it. 

Thanks for your advice.

Volker