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Subject: Re: UBIFS question
To: Martin Townsend <mtownsend1973@gmail.com>,
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From: Richard Weinberger <richard@nod.at>
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Am 17.03.2016 um 16:39 schrieb Martin Townsend:
>> I guess you're more worried about bitflips than blocks becoming bad
>> (which, AFAIK, can only happen when writing or erasing a block, not
>> when reading it).
>> If bitflips detection/prevention is what your looking for, I guess
>> ubihealthd (developed by Richard) could help.
>>
>> [1]https://lwn.net/Articles/663751/
>> [2]https://lkml.org/lkml/2015/3/29/31
>>
>>
> 
> Looks very promising, thank you for the links.  Bitflip detection is
> definitely something I am looking for.  If I could get some metrics on
> bitflips detected even better :) I will take a closer look.

To clarify, UBI does already bitflip detection and then
"tortures" a block to figure whether it is good or not.
But only upon read. So, if you very seldom read from a
page read disturb may hit you.
This is why I did the ubi-healthd, it allows you to trigger
read of all data (UBI meta and payload) to detect read disturb
soonish.

Thanks,
//richard