Re: OpenBSD versus semaphores

On 2019-01-08 07:14, Tom Lane wrote:
> I've been toying with OpenBSD lately, and soon noticed a seriously
> annoying problem for running Postgres on it: by default, its limits
> for SysV semaphores are only SEMMNS=60, SEMMNI=10.  Not only does that
> greatly constrain the number of connections for a single installation,
> it means that our TAP tests fail because you can't start two postmasters
> concurrently (cf [1]).
> 
> Raising the annoyance factor considerably, AFAICT the only way to
> increase these settings is to build your own custom kernel.

You don't need to build your custom kernel to change those settings.

Just add:

kern.seminfo.semmni=20

to /etc/sysctl.conf and reboot

/Mikael