Re: shared memory on OS X - 7.4beta4 - Mailing list pgsql-general

From Eric Soroos
Subject Re: shared memory on OS X - 7.4beta4
Date
Msg-id 5B7A243E-0973-11D8-AAD7-0003930F2A6C@soroos.net
Whole thread Raw
In response to Re: shared memory on OS X - 7.4beta4  (Jim Crate <jcrate@deepskytech.com>)
List pgsql-general
Slightly off topic confirmations...

>>> And here are are the default settings for OS X 10.2.6:
>>>
>>>     sysctl -w kern.sysv.shmmax=4194304

Seems to be the default on 10.2.8 as well.

10.1.5 doesn't seem to have a kern.sysv.* section:

[broccoli:~] erics% sysctl kern.sysv.shmmax
second level name sysv in kern.sysv.shmmax is invalid

>>
>> Well, I can only say that if I lower shmmax to that value, initdb
>> picks
>> max_connections = 50
>> shared_buffers = 300
>
> I just did a fresh install of 7.4b5 on a fresh install of MacOS 10.3,
> and initdb
> picked those same values for postgresql.conf.  PostgreSQL started up
> the first
> time successfully, but then refused to start again even after
> restarting the
> computer until I reduced shared_buffers.

I've had cases in 10.1.x where after hammering on the database for a
while and having to restart it, there was no longer enough shared
memory to start postgres, requiring a restart of the computer. On 10.1,
I couldn't even get it to change the shmmax value, necessitating some
very low buffer numbers (nearly out of the box for pg 7.2, yes, that
bad).



eric


pgsql-general by date:

Previous
From: Scott Ribe
Date:
Subject: Re: SCSI vs. IDE performance test
Next
From: Ron Jr
Date:
Subject: Re: [OT] Choosing a scripting language.