From: Bruce Momjian <bruce@momjian.us>
To: Julien Cigar <jcigar@ulb.ac.be>
Cc: pgsql-performance@postgresql.org
Subject: Re: shared_buffers/effective_cache_size on 96GB server
Date: Wed, 10 Oct 2012 12:10:12 -0400
Message-ID: <20121010161012.GE11892@momjian.us> (raw)
In-Reply-To: <50752DB2.6060004@ulb.ac.be>
References: <CADKbJJUTr9ZWkbajR-7_6qaAsWH0=09=2AMo67C_Az-raKZE4w@mail.gmail.com>
<50752DB2.6060004@ulb.ac.be>
On Wed, Oct 10, 2012 at 10:11:30AM +0200, Julien Cigar wrote:
> On 10/10/2012 09:12, Strahinja Kustudić wrote:
> >Hi everyone,
>
> Hello,
>
> >
> >I have a Postgresql 9.1 dedicated server with 16 cores, 96GB RAM
> >and RAID10 15K SCSI drives which is runing Centos 6.2 x64. This
> >server is mainly used for inserting/updating large amounts of data
> >via copy/insert/update commands, and seldom for running select
> >queries.
> >
> >Here are the relevant configuration parameters I changed:
> >
> >shared_buffers = 10GB
>
> Generally going over 4GB for shared_buffers doesn't help.. some of
> the overhead of bgwriter and checkpoints is more or less linear in
> the size of shared_buffers ..
>
> >effective_cache_size = 90GB
>
> effective_cache_size should be ~75% of the RAM (if it's a dedicated server)
Why guess? Use 'free' to tell you the kernel cache size:
http://momjian.us/main/blogs/pgblog/2012.html#May_4_2012
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
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To: pgsql-performance@postgresql.org
Cc: bruce@momjian.us, jcigar@ulb.ac.be
Subject: Re: shared_buffers/effective_cache_size on 96GB server
In-Reply-To: <20121010161012.GE11892@momjian.us>
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