Re: postgresql 18 and shm

[Martin Husemann <martin%duskware.de@localhost>]

On Wed, Jul 15, 2026 at 11:16:02AM +0200, Marc Baudoin wrote:
> Have a look at this thread from last year:
> 
> https://mail-index.netbsd.org/pkgsrc-users/2025/10/25/msg042112.html
> 
> The setting that works for me is:
> 
> kern.ipc.semmni=20
> kern.ipc.semmns=200
> 
> I still think changing the default values or, at least,
> displaying a warning when installing the package or starting
> PostgreSQL with insufficient values would be nice.

I was confused back then, as I overlooked that I had raised the defaults
on my PostgesSQL machine already by adding this to /etc/sysctl.conf:

# The PostgresSQL server may need additional semmaphore resources
kern.posix.semmax=256
kern.ipc.semmns=256                        
kern.ipc.semmni=64


Not sure how I invented those numbers. The defaults are

kern.posix.semmax = 128
kern.ipc.semmns = 60
kern.ipc.semmni = 10

and it seems kern.ipc.semmni is the one you bumped into.

Martin