> Hi, > > I have very bad bgwriter statistics on a server which runs since many > weeks > and it is still the same after a recent restart. > There are roughly 50% of buffers written by the backend processes and the > rest by checkpoints. > The statistics below are from a server with 140GB RAM, 32GB shared_buffers > and a runtime of one hour. > > As you can see in the pg_buffercache view that there are most buffers > without usagecount - so they are as free or even virgen as they can be. > At the same time I have 53% percent of the dirty buffers written by the > backend process.
There are some nice old threads dealing with this - see for example http://postgresql.1045698.n5.nabble.com/Bgwriter-and-pg-stat-bgwriter-buffers-clean-aspects-td2071472.html http://postgresql.1045698.n5.nabble.com/tuning-bgwriter-in-8-4-2-td1926854.html and there even some nice external links to more detailed explanation http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm regards Tomas -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
