Re: Limited Shared Buffer Problem

On Fri, Jan 29, 2010 at 9:37 AM, **Rod MacNeil
<rmacneil(at)interactdirect(dot)com> wrote:
> Hi All,
>
> I have a server running CentOS5 with 6gb of memory that will run postgres
> 8.3 exclusively.
> I would like to allocate 4gb of the memory to shared buffers for postgres.
> I have modified some kernel settings as follows:
>
> shmall  1048576 pages  4,294,967,296 bytes
> shmmax 4,294,967,295 bytes
>
> I can set the postgres config to shared_buffers = 2700MB but no higher.
> If I try shared_buffers = 2750MB the server fails to start with a message it
> cannot allocate memory:

Are you running 32 or 64 bit Centos?

Also, that's a rather high setting for shared_buffers on a 6G machine.
Generally 2G or so should be plenty unless you have actual data sets
that are larger than that.