Hi, On 7 December 2012 14:17, ac@xxxxxx <ac@xxxxxx> wrote: > I have questions about Linux Write cache sizing: > > 1) /proc/sys/vm/dirty_ratio : current value (default) 20 > 2) /proc/sys/vm/dirty_background_ratio: current value (default) 10 > > I am using Ubuntu 12.04 (8GB RAM) and PostgreSQL 9.2.1, what values of these kernel ratios > should be set for better PostgreSQL database performance? Read this thread: http://archives.postgresql.org/pgsql-performance/2011-10/msg00076.php Mainly, - http://archives.postgresql.org/pgsql-performance/2011-10/msg00078.php - and http://archives.postgresql.org/pgsql-performance/2011-10/msg00080.php To sum up: - with 8G RAM you should be fine with the defaults - keep keep dirty_ratio lower than the size of your disk controller cache - you can use dirty_bytes and dirty_background_bytes in recent kernels -- Ondrej Ivanic (http://www.linkedin.com/in/ondrejivanic) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general