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Message-ID: <4C16B97F.4080201@gmail.com>
Date: Tue, 15 Jun 2010 00:21:35 +0100
From: Tom Wilcox <hungrytom@gmail.com>
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To: Robert Haas <robertmhaas@gmail.com>,
 pgsql-performance@postgresql.org
Subject: Re: requested shared memory size overflows size_t
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Thanks. I will try with a more sensible value of wal_buffers.. I was 
hoping to keep more in memory and therefore reduce the frequency of disk 
IOs..

Any suggestions for good monitoring software for linux?

On 15/06/2010 00:08, Robert Haas wrote:
> On Mon, Jun 14, 2010 at 2:53 PM, Tom Wilcox<hungrytom@gmail.com>  wrote:
>    
>> maintenance_work_mem=4GB
>> work_mem=4GB
>> shared_buffers=4GB
>> effective_cache_size=4GB
>> wal_buffers=1GB
>>      
> It's pretty easy to drive your system into swap with such a large
> value for work_mem - you'd better monitor that carefully.
>
> The default value for wal_buffers is 64kB.  I can't imagine why you'd
> need to increase that by four orders of magnitude.  I'm not sure
> whether it will cause you a problem or not, but you're allocating
> quite a lot of shared memory that way that you might not really need.
>
>