Re: feature suggestion to handle read errors during re-sync of raid5

[John Robinson <john.robinson@anonymous.org.uk>]

On 01/02/2010 16:28, Mikael Abrahamsson wrote:
[...]
> Since the drive has ECC, it would be interesting to see the amount of 
> read errors ECC has corrected. Would also be interesting to know if the 
> drive will rewrite a sector if it's ECC corrected, so that ECC doesn't 
> have to kick in next time (or if they're actually operating in so narrow 
> margins that they actually use the ECC constantly because the s/n ratio 
> is bad and that this is part of the design).

I think that's exactly what's going on. There may also be some level of 
correction above which the drive will transparently rewrite after read, 
e.g. if the limit for correctability is X bits per sector, it'll 
automatically rewrite when it's had to correct 90% of X bits, but any 
less than that is just normal operation.

Cheers,

John.