bvermeul@devel.blackstar.nl wrote:
>
> On 27 Jul 2001, Eric W. Biederman wrote:
>
> > Hans Reiser <reiser@namesys.com> writes:
> >
> > > This "feature" of not guaranteeing that a write that is in progress when the
> > > machine crashes will
> > >
> > > not write garbage, has been present in most Unix filesystems for about 25 years
> > > of Unix history.
> >
> > A write in progress causing garabage when the power is lost is a
> > driver, and drive thing.
> >
> > stock unix behavior is that it delays writes for up to 30 seconds,
> > which in case of a crash could mean you have old data on disk. Not
> > wrong data. This is helped because in stock unix filesystems blocks
> > are rarely reallocated or moved. In reiserfs with the btree at least
> > some kinds of data are moved all over the disk.
> >
> > I want to suspect a btree problem on the block jumping around (it's
> > a good canidate). But unless you have messed up metadata journalling
> > btree writes are journaled. The reason I am suspecting the btree is
> > that most source code files are small so probably don't have complete
> > filesystem blocks of their own.
>
> Possibly. We're talking 130 kByte in total. The above is the reason why
> I don't like using reiserfs on my development system. My files get
> completely garbled, with the data randomly distributed over the files last
> touched. (Object files, dependency files, source files and header files)
> I don't mind loosing data I've just written, but I *hate* it when it
> garbles all my files.
>
> > If you can give me an explanation of what would cause the described
> > behavior of small files swapping their contents I would believe I
> > would feel more secure than just a reflex ``we don't garantee all of the
> > data written before power failure''.
>
> Bas Vermeulen
>
> --
> "God, root, what is difference?"
> -- Pitr, User Friendly
>
> "God is more forgiving."
> -- Dave Aronson
You should not see old data being corrupted. If you are seeing it with a recent ReiserFS version,
we'd like your help in reproducing it.
Hans
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This archive was generated by hypermail 2b29 : Tue Jul 31 2001 - 21:00:34 EST