Re: MacOS X Shared Buffers (SHMMAX)?

Steve Lane <slane@fmpro.com>

From: Steve Lane <slane@fmpro.com>
To: "Command Prompt, Inc." <pgsql-general@commandprompt.com>, <pgsql-general@postgresql.org>
Cc: <jlx@commandprompt.com>
Date: 2002-05-21T01:59:32Z
Lists: pgsql-general, pgsql-sql
On 5/20/02 9:25 PM, "Command Prompt, Inc." <pgsql-general@commandprompt.com>
wrote:

> Good day,
> 
> Does anyone have any experience in increasing the amount of shared memory
> buffers available to Mac OS X/Darwin? When starting with more than 128
> backend connections on a test G3 I encounter:
> 
> ------------------------------------------------------------------------------
> -----
> IpcMemoryCreate: shmget(key=5432001, size=33357824, 03600) failed: Invalid
> argument
> 
> This error usually means that PostgreSQL's request for a shared memory
> segment exceeded your kernel's SHMMAX parameter.  You can either
> reduce the request size or reconfigure the kernel with larger SHMMAX.
> ------------------------------------------------------------------------------
> -----
> 
> However, I can find no helpful information looking around for how Darwin
> handles this configuration. Hopefully it does not require a recompile of
> the Kernel. ;)


Actually --- :-> I'm no expert on this topic, but Darwin is BSD and I do
recall a post on this very topic, to the effect that the poster believed
some flavors of BSD, possibly MOSX included, do require rebuilding the
kernel to change this value.

As a MOSX user I'd certainly love to be found wrong.

-- sgl


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Steve Lane

Vice President
Chris Moyer Consulting, Inc.
833 West Chicago Ave Suite 203

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