Re: Still problems with memory swapping and server load

From: Alvar Freude <alvar(at)a-blast(dot)org>
To: Markus Wollny <Markus(dot)Wollny(at)computec(dot)de>, pgsql-general(at)postgresql(dot)org
Subject: Re: Still problems with memory swapping and server load
Date: 2002-06-26 16:18:26
Message-ID: 1399660000.1025108306@gnarzelwicht.delirium-arts.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Hi,

-- Markus Wollny <Markus(dot)Wollny(at)computec(dot)de> wrote:

> Mem: 1029400K av, 1023264K used, 6136K free, 0K shrd, 7176K
> buff

you use still too much RAM, there are only 7 MB left for OS caching, this
is really not enough!

> shared_buffers = 32768

256 MB shared memory; this might OK, if you don't use other large
applications (e.g. a big mod_perl enabled Apache).

> sort_mem = 8192 (16384 or 32768 didn't help either)

Each sort can take up to 8 MB RAM; if you have some queries which needs
e.g. 3 big sorts and have 30 from this in parallel, this takes ~720 MB RAM.

Try to reduce a) memory consumption of other applications, b) Memory
consumption of postgres: if you have a lot of big sorts, try to reduce them
in your application or reduce sort_mem; also 20000 shared buffers is mostly
enough.

Also, sorting buffers on disk should be NOT an a RAID 5 array (slow(er)
writes).

With my experience, the BIOS should at least have 200 MB Cache on a 1 GB
Machine.

Ciao
Alvar, Just my ideas ... :-)

--
// Unterschreiben! http://www.odem.org/informationsfreiheit/
// Internet am Telefon: http://www.teletrust.info/
// Das freieste Medium? http://www.odem.org/insert_coin/
// Blaster: http://www.assoziations-blaster.de/

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Bill Moran 2002-06-26 16:18:33 Re: How to run multi-processor question
Previous Message Elaine Lindelef 2002-06-26 16:17:39 Re: What is a tuple?