Re: Are linux-fs's drive-fault-tolerant by concept?

John Bradford (john@grabjohn.com)
Sun, 20 Apr 2003 18:12:54 +0100 (BST)


>
> On Sun, 20 Apr 2003 14:59:00 +0100 (BST)
> John Bradford <john@grabjohn.com> wrote:
>
> > > Ok, you mean active error-recovery on reading. My basic point is the
> > > writing case. A simple handling of write-errors from the drivers level and
> > > a retry to write on a different location could help a lot I guess.
> >
> > A filesystem is not the place for that - it could either be done at a
> > lower level, like I suggested in a separate post, or at a much higher
> > level - E.G. a database which encounters a write error could dump it's
> > entire contents to a tape drive, shuts down, and page an
> > administrator, on the basis that the write error indicated impending
> > drive failiure.
>
> Can you tell me what is so particularly bad about the idea to cope a
> little bit with braindead (or just-dying) hardware?

Nothing - what is wrong is to implement it in a filesystem, where it
does not belong.

> See, a car (to name a real good example) is not primarily built to have
> accidents.

Stunt cars are built to survive accidents. All cars _could_ be built
like stunt cars, but they aren't.

> Anyway everybody might agree that having a safety belt built into it
> is a good idea, just to make the best out of a bad situation - even
> if it never happens - , or not?

Exactly, that is why most modern hard disks retry on write failiure.

John.
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