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

[Stephan von Krawczynski <skraw@ithnet.com>]

On Sat, 19 Apr 2003 23:13:53 +0200
Jos Hulzink <josh@stack.nl> wrote:

> [...]
> Fault tolerance in a filesystem layer means in practical terms that you are 
> guessing what a filesystem should look like, for the disk doesn't answer that
> 
> question anymore. IMHO you don't want that to be done automagically, for it 
> might go right sometimes, but also might trash everything on RW filesystems.

Let me clarify again: I don't want fancy stuff inside the filesystem that
magically knows something about right-or-wrong. The only _very small_
enhancement I would like to see is: driver tells fs there is an error while
writing a certain block => fs tries writing the same data onto another block.
That's it, no magic, no RAID stuff. Very simple.

> Fault tolerance OK, but the fs layer should only detect errors reported by
> the lower level drivers and handle them gracefully (which is something that
> might need impovement a little for some fs drivers), or else trust the data
> it gets. 

You are completely right, I don't want any more: nice management of an error a
low-level driver reports to the fs. Only I would like to see as an fs-answer to
this: ok, let's try another part of the media. Currently it just sinks like
titanic.

Regards,
Stephan