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Subject: RE: NAND BBT corruption on MPC83xx
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Atlant Schmidt <aschmidt@dekaresearch.com>
Date: Thu, 23 Jun 2011 11:31:25 +0300
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Cc: Scott Wood <scottwood@freescale.com>,
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On Mon, 2011-06-20 at 07:22 -0400, Atlant Schmidt wrote:
> 
>   As far as I know (and I'm sure the list will correct
>   me if I'm wrong! ;-) ), neither UBI nor UBIFS nor any
>   Linux layer provides this routine scrubbing; you have
>   to code it up yourself, probably by accessing the
>   device at the UBI (underlying block device/LEB) layer. 

UBI will scrub all LEBs with bit-flips once they are read.
But if you have bit-flips in an LEB and it is never read, it will never
be scrubbed. And erasures of the neighboring PEBs may turn bit-flips
into hard errors.

To force scrubbing, the easies way is to just read all volumes, like

dd if=/dev/ubi0_i of=/dev/null bs=4096

for each i.

-- 
Best Regards,
Artem Bityutskiy