Re: [Lsf-pc] Linux kernel impact on PostgreSQL performance

Dave Chinner <david@fromorbit.com> write:

> Essentially, changing dirty_background_bytes, dirty_bytes and
> dirty_expire_centiseconds to be much smaller should make the
> kernel start writeback much sooner and so you shouldn't have to
> limit the amount of buffers the application has to prevent major
> fsync triggered stalls...

Is there any "rule of thumb" about where to start with these?  For
example, should a database server maybe have dirty_background_bytes
set to 75% of the non-volatile write cache present on the
controller, in an attempt to make sure that there is always some
"slack" space for writes?

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company