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().

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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