Re: Configuration settings (shared_buffers, etc) in Linux: puzzled - Mailing list pgsql-performance

From Greg Smith
Subject Re: Configuration settings (shared_buffers, etc) in Linux: puzzled
Date
Msg-id Pine.GSO.4.64.0801241349420.7217@westnet.com
Whole thread Raw
In response to Configuration settings (shared_buffers, etc) in Linux: puzzled  (Rick Schumeyer <rschumeyer@ieee.org>)
List pgsql-performance
On Thu, 24 Jan 2008, Rick Schumeyer wrote:

> On a linux box (Linux db1 2.6.18.8-md #1 SMP Wed May 23 17:21:37 EDT 2007
> i686 GNU/Linux)
> I edited postgresql.conf and changed:
>
> shared_buffers = 5000           work_mem = 16384
> max_stack_depth = 4096
>
> and then restarted postgres.  The puzzling part is that postgres actually
> started.  When I have done this on other boxes, I had to edit kernel settings
> to allow for more shared memory.

You can confirm whether the settings are actually taking like this:

$ psql
Welcome to psql 8.2.4, the PostgreSQL interactive terminal.

postgres=# show shared_buffers;
  shared_buffers
----------------
  256MB
(1 row)

Since your shared_buffers setting should probably be in the hundreds of
megabytes range if you want good performance, you may need to update your
kernel settings anyway, but the above will let you see what the server is
actually starting with.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD

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