Hi, thank you very much!
On 7 Dec 2012, at 11:47 AM, Ondrej Ivanič wrote:
> Hi,
>
> On 7 December 2012 14:17, ac@hsk.hk <ac@hsk.hk> 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)