Re: end to end error recovery musings

H. Peter Anvin
2007-02-24T00:03:51Z

Ric Wheeler wrote:
>
> We still have the following challenges:
>
> (1) read-ahead often means that we will retry every bad sector at
> least twice from the file system level. The first time, the fs read
> ahead request triggers a speculative read that includes the bad sector
> (triggering the error handling mechanisms) right before the real
> application triggers a read does the same thing. Not sure what the
> answer is here since read-ahead is obviously a huge win in the normal case.
>

Probably the only sane thing to do is to remember the bad sectors and
avoid attempting reading them; that would mean marking "automatic"
versus "explicitly requested" requests to determine whether or not to
filter them against a list of discovered bad blocks.

-hpa