Re: shared_buffers vs. -B flag: 7.4

Hmmm. This was reproduced at a customer site by
a very meticulous dba. I'll check back with him.
But I'm glad to know it is not an on-going problem.

thanks for your quick response

--elein

On Sun, Jan 23, 2005 at 02:15:07PM -0500, Tom Lane wrote:
> elein(at)varlena(dot)com (elein) writes:
> > However, if you use the -B option on the pg_ctl
> > start up, postgres starts up fine. And
> > the shared_buffers value shown by show
> > is the higher value.
>
> It behaves as expected for me, in both 7.4 and CVS tip. Are you sure
> your test case wasn't such that the higher -B value in fact worked?
> (For instance, maybe you stopped another postmaster that was using some
> of the shmem.)
>
> $ postmaster -B 65000
> FATAL: could not create shared memory segment: Not enough space
> DETAIL: Failed system call was shmget(key=5474001, size=543997952, 03600).
> HINT: This error usually means that PostgreSQL's request for a shared memory segment exceeded available memory or swap space. To reduce the request size (currently 543997952 bytes), reduce PostgreSQL's shared_buffers parameter (currently 65000) and/or its max_connections parameter (currently 100).
> The PostgreSQL documentation contains more information about shared memory configuration.
> $
>
> regards, tom lane
>
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