Re: the " 'official' point of view" expressed by kernelnewbies.org

[Edward Shishkin <edward@namesys.com>]

Tom Reinhart wrote:
> Anyone with serious need for data integrity already uses RAID, so why 
> add brand new complexity for a solved problem?
> 
> RAID is great at recovering data, but not detecting errors.  File system 
> can detect errors with checksum.  What is missing is an API between 
> layers for filesystem to say "this sector is bad, go rebuild it."
> 

Actually we dont need a special API: kernel should warn and recommend
running fsck, which scans the whole tree and handles blocks with bad
checksums.

> This seems like a much more simple and useful thing than adding ECC into 
> the filesystem itself.

checksumming is _not_ much more easy then ecc-ing from implementation
standpoint, however it would be nice, if some part of errors will get
fixed without massive surgery performed by fsck


> 
> 
>>>> How about we switch to ecc, which would help with bit rot not sector
>>>> loss?
>>>
>>>
>>>
>>> Interesting aspect.
>>>
>>> Yes, we can implement ECC as a special crypto transform that inflates
>>> data. As I mentioned earlier, it is possible via translation of key
>>> offsets with scale factor > 1.
>>>
>>> Of course, it is better then nothing, but anyway meta-data remains
>>> ecc-unprotected, and, hence, robustness is not increased..
>>>
> 
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