SUMMARY: Semaphores

From: Mark (
Date: Mon May 15 1995 - 03:12:26 CDT


My problem:
> madgems:/etc root# ipcs
> IPC status from <running system> as of Fri May 12 19:51:26 1995
> Message Queue facility not in system.
> Shared Memory:
> Semaphore facility not in system.
> How do I switch them on, and why arent they in this (virgin) OS end user
> install?.

Turns out someone previously had setup our systems for ingres and hadn't
documented it. Decidedly annoying.

The problem is semaphores are not turned on by default (at least on 2.3 SS10's)
so you have to forceload them in /etc/systems. I discovered this myself about
an hour after sending the above email so I managed to get it up and running.
The disks are now winging their way to Madrid on a Quantas flight.

Whilst semaphores _do_ auto load themselves when you actually use one, the
ingres startup scripts do an 'ipcs' and grok the output so if semaphores are
not forceloaded ingres dies complaining that no semaphores exists.

My /etc/system has in it:

* for ingres
forceload: sys/semsys
forceload: sys/shmsys
set semsys:seminfo_semmap=10
set semsys:seminfo_semmni=100
set semsys:seminfo_semmns=1000
set semsys:seminfo_semmnu=30
set semsys:seminfo_semmsl=50
set semsys:seminfo_semopm=10
set semsys:seminfo_semume=10
set semsys:seminfo_semusz=96
set semsys:seminfo_semvmx=32767
set semsys:seminfo_semaem=16384

set shmsys:shminfo_shmmax=10000000
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni=100
set shmsys:shminfo_shmseg=10

This keeps ingres happy, me happy and my stress levels down. I think.

Thanks to:
From: (Jim Leahy)
From: ld kelley <>
From: (Michael Pearlman)
From: "Cynthia A. Zorn" <>
From: (Syd Weinstein)
From: (Kevin Sheehan {Consulting Poster Child})
From: Garry Robbins <>
From: (Glenn Satchell - Uniq Professional Services)

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