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Subject: Re: protecting some processes from out-of-swap killer
References: <alpine.BSF.2.00.1504251316020.43520@woozle.rinet.ru>
 <20150425104336.GD13141@ivaldir.etoilebsd.net>
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Date: Tue, 28 Apr 2015 11:51:03 +0200
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From: "Ronald Klop" <ronald-lists@klop.ws>
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On Sat, 25 Apr 2015 13:15:32 +0200, Dmitry Morozovsky <marck@rinet.ru>  
wrote:

> On Sat, 25 Apr 2015, Baptiste Daroussin wrote:
>
>> > However, sometimes postgres processes got killed by 'out of swap  
>> space'.
>> > I suppose the source of problem could be that VSZ size of postgres  
>> processes
>> > (8-9 G) is bigger than swap congigured (4G).
>> >
>> > Is there any way to prevent this, besides reallocating space for swap?
>>
>> protect(1) ?
>
> Of course.  I really do not understand how google hides the man page  
> from me.
>
> Thanks, and sorry fot the noise.
>


The OS trying to kill a process is probably not what you want. So when you  
protect(1) postgres the OS will kill another process, which I hope is not  
running without reason.
My advice would be to
- or increase your swap space
- or tune postgresql to use less memory
- or limit tmpfs (tmpfs uses swap if RAM is short)
- or tune zfs to use less memory

Regards,
Ronald.