Re: shared memory on OS X - 7.4beta4

John DeSoi <jd(at)icx(dot)net> writes:
> OK, I compiled beta 5 and put my rest SHMMAX back to the default
> settings as provided by OS X. Still the same error:

> FATAL: could not create shared memory segment: Invalid argument
> DETAIL: Failed system call was shmget(key=5432001, size=10444800,
> 03600).
> HINT: 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.
> To reduce the request size (currently 10444800 bytes), reduce
> PostgreSQL's shared_buffers parameter (currently 1000) and/or its
> max_connections parameter (currently 100).

There is something very wrong here. On my OS X machine, initdb selects
non-default shared_buffers and max_connections (300 and 50 respectively,
when using 7.4beta5). Why is that failing to happen on yours? I can
see two possibilities: either initdb is failing to notice that it needs
smaller-than-default values, or it's somehow failing to insert those
values into the constructed postgresql.conf file. You could determine
which is happening by looking at the output of initdb to see what it
reports.

[ thinks for a bit... ] Hmm. You *are* using the postgresql.conf file
that initdb built, aren't you?

regards, tom lane