Message-ID: <bf15a32c5a7d6a3f1c5bc0a6aff89b5f17eae805.camel@cybertec.at>
Subject: Re: RHEL-8 Kernel Settings
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Johannes Truschnigg <johannes@truschnigg.info>,
	pgsql-admin@lists.postgresql.org
Date: Fri, 11 Jun 2021 09:12:28 +0200
In-Reply-To: <20210611070617.GB5793@vault.lan>
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	 <a21a096321d234c1fd1a3cb9842df8b8002aae34.camel@cybertec.at>
	 <20210611070617.GB5793@vault.lan>
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On Fri, 2021-06-11 at 09:06 +0200, Johannes Truschnigg wrote:
> On Fri, Jun 11, 2021 at 08:56:13AM +0200, Laurenz Albe wrote:
> > [...]
> > I recommend setting
> > 
> >   vm.overcommit_memory = 2
> 
> Be careful with this though, most applications no not allocate memory as
> thoughtfully as Postgres - so if your server is running any other kind of
> service/software in addition to Postgres, you should make sure that can
> survive Linux not overcommitting like there's no tomorrow, too.

On the contrary: if there is some software that allocates memory like crazy,
you want to disable overcommit, so that you get a nice OOM error rather
than killed processes, which result in PostgreSQL going through crash
recovery.

But I think that running such a misbehaving program on a database
machine is a bad idea.

Yours,
Laurenz Albe
-- 
Cybertec | https://www.cybertec-postgresql.com