Re: Linux max on shared buffers?

How does one increase the SHMMAX?  Does it require recompiling the kernel?

Terry Fielder
Network Engineer
Great Gulf Homes / Ashton Woods Homes
terry@greatgulfhomes.com

> -----Original Message-----
> From: pgsql-general-owner@postgresql.org
> [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Martin Dillard
> Sent: Wednesday, July 10, 2002 1:45 PM
> To: pgsql-general@postgresql.org
> Subject: [GENERAL] Linux max on shared buffers?
>
>
> We are trying to throw a lot of memory at PostgreSQL to try to boost
> performance. In an attempt to put our entire database into
> memory, I want to
> allocate 2 to 3 GB out of 4 GB on a dual processor server
> running Red Hat
> Linux 7.3 and PostgreSQL 7.2.1. We only expect 4 or 5
> concurrent backends.
>
> When I try to allocate 2 GB or more, I get the following
> error when I try to
> start PostgreSQL (after setting kernel.shmall and kernel.shmmax
> appropriately):
>
> IpcMemoryCreate: shmat(id=163840) failed: Cannot allocate memory
>
> I can safely allocate a little under 2 GB. Is this a Linux
> upper bound on
> how much memory can be allocated to a single program? Is there another
> kernel parameter besides kernel.shmall and kernel.shmmax that
> can be set to
> allow more memory to be allocated?
>
>
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