Re: FreeBSD 5.2.1, postgresql 7.4.5 and shared memory settings

On Sun, Jan 30, 2005 at 03:21:25PM -0500, Rick Apichairuk wrote:

> I am trying to increase the number of max_connections to 200 and found
> out I couldn't even start postgresql. So I tried to increase
> max_connections gradually (currently at 50 from 40 default) and adjust
> shared memory settings along the way. Even at 50 max_connections, I
> still cannot get postgresql to start.
>
> The following is the error message I receive:
>
> pgsql FATAL: could not create shared memory segment: Invalid argument
> DETAIL: Failed system call was shmget(key=5432001, size=35323904,
> 03600).

> To reduce the request size (currently 35323904 bytes),

> kern.ipc.shmmax: 33554432

Looks like the request size is just higher than shmmax. The majority of
the request is for the shared buffers, so if you can't increase shmmax
any more you can reduce your shared buffers downwards from 4096 and this
will give you some room for more connections.

Richard