Horrible PostgreSQL performance with NFS

Jim C. Nasby decibel at decibel.org
Wed Jan 18 17:15:52 PST 2006

On Wed, Jan 18, 2006 at 05:11:15PM -0800, Brooks Davis wrote:
> On Wed, Jan 18, 2006 at 06:58:47PM -0600, Jim C. Nasby wrote:
> > On Sat, Jan 14, 2006 at 06:42:02AM -0800, Arne Woerner wrote:
> > > Did you do those "dd" tests with small block sizes (like 1byte:
> > > bs=1), like somebody on one of those lists suggests, too? Then we
> > > could see, if there is a high latency that ruins everything...
> > 
> > FYI, PostgreSQL does 8kB I/O by default. This can only be changed by
> > modifying a header file.
> That's definitely small in my book (certainly compared to the 1MB block
> size the first responder suggested), knowing that, you should
> definitely do dd tests with 8k blocks since that's the best performance you
> are likely to get.

Agreed, it is small from a OS/filesystem viewpoint, but it's also
nowhere near 1 byte which is the test that had been suggested. :)
Jim C. Nasby, Database Architect                decibel at decibel.org 
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