Re: shared_buffers/effective_cache_size on 96GB server

[Strahinja Kustudić <strahinjak@xxxxxxxxxxx>]

I will change those, but I don't think this is that big of an issue if most of the IO is done by Postgres, since Postgres has it's own mechanism to tell the OS to sync the data to disk. For example when it's writing a wal file, or when it's writing a check point, those do not get cached.

Regards,
Strahinja

On Wed, Oct 10, 2012 at 4:38 PM, Shaun Thomas <sthomas@xxxxxxxxxxxxxxxx> wrote:

On 10/10/2012 09:35 AM, Strahinja Kustudić wrote:

#sysctl vm.dirty_ratio
vm.dirty_ratio = 40
# sysctl vm.dirty_background_ratio
vm.dirty_background_ratio = 10

Ouuuuch. That looks a lot like an old RHEL or CentOS system. Change those ASAP. Currently your system won't start writing dirty buffers until it hits 9.6GB. :(

shows that these values are even higher by default. When you said
RAID buffer size, you meant the controllers cache memory size?

Yeah, that. :)

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-444-8534
sthomas@xxxxxxxxxxxxxxxx

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