Re: New Linux xfs/reiser file systems

> Hi,
>
> On Fri, May 04, 2001 at 01:49:54PM -0400, Bruce Momjian wrote:
> > >
> > > Performance doing what? XFS has known performance problems doing
> > > unlinks and truncates, but not synchronous IO. The user should be
> > > using fdatasync() for databases, btw, not fsync().
> >
> > This is hugely helpful. In PostgreSQL 7.1, we do use fdatasync() by
> > default it is available on a platform.
>
> Good --- fdatasync is defined in SingleUnix, so it's probably safe to
> probe for it and use it by default if it is there.
>
> The 2.2 Linux kernel does not have fdatasync implemented, but glibc
> will fall back to fsync if that's all that the kernel supports. 2.4
> implements both with the required semantics.

OK, that is something we found too, that fdatasync() was there on some
platforms, but was really just an fsync(). I believe some HPUX
platforms had that.

OK, so they need a 2.4 kernel to properly test performance of Reiser/xfs
with fdatasync().

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