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Re: SHMMAX seems entirely broken in OS X 10.4.2

From: Jeff - <threshar(at)torgo(dot)978(dot)org>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: SHMMAX seems entirely broken in OS X 10.4.2
Date: 2005-08-30 02:14:37
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Lists: pgsql-hackers
On Aug 29, 2005, at 8:18 PM, Tom Lane wrote:

> Has anyone been able to set kern.sysv.shmmax above 4MB at all in  
> latest
> OS X?  I just spent a while trying what seemed every possible
> permutation of setting up /etc/sysctl.conf and editing /etc/rc  
> directly,
> and it just fails (symptom: sysctl shows shmmax as -1, and Postgres
> cannot start).
yeah, you need to set shmmax and shmall.  shmall seems to be measured  
in pages.
Here's the settings I've been using:

skittlebrau:/etc root# grep shm rc
# sysctl -w kern.sysv.shmmax=4194305 kern.sysv.shmmin=1  
kern.sysv.shmmni=32 kern.sysv.shmseg=8 kern.sysv.shmall=1024
sysctl -w kern.sysv.shmmax=335544320
sysctl -w kern.sysv.shmmin=1
sysctl -w kern.sysv.shmmni=32
sysctl -w kern.sysv.shmseg=16
sysctl -w kern.sysv.shmall=327680

and just to verify:

skittlebrau:/etc root# sysctl -a | grep shm
kern.sysv.shmmax: 335544320
kern.sysv.shmmin: 1
kern.sysv.shmmni: 32
kern.sysv.shmseg: 16
kern.sysv.shmall: 327680

I've been running PG ith 10k shared bufs for a while.

The pain is sometimes /ec/rc gets rewritten :(

Jeff Trout <jeff(at)jefftrout(dot)com>

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