Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance

От: Mark Kirkwood
Тема: Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance
Дата: ,
Msg-id: 42A01E80.2030507@paradise.net.nz
(см: обсуждение, исходный текст)
Ответ на: Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance tuning)  ("Martin Fandel")
Ответы: Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance tuning)  ("Martin Fandel")
Список: pgsql-performance

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postgresql-8.0.1 performance tuning  ("Martin Fandel", )
 Re: postgresql-8.0.1 performance tuning  (John A Meinel, )
  Re: postgresql-8.0.1 performance tuning  ("Martin Fandel", )
 Re: postgresql-8.0.1 performance tuning  (Cosimo Streppone, )
  Re: postgresql-8.0.1 performance tuning  (Mark Kirkwood, )
   Re: postgresql-8.0.1 performance tuning  (Cosimo Streppone, )
    Re: postgresql-8.0.1 performance tuning  (Mark Kirkwood, )
   SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance tuning)  (Paul McGarry, )
    Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance  (Mark Kirkwood, )
     Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance tuning)  ("Martin Fandel", )
      Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance  (Mark Kirkwood, )
       Re: SHMMAX / SHMALL Was (Re: postgresql-8.0.1 performance tuning)  ("Martin Fandel", )
  Re: postgresql-8.0.1 performance tuning  ("Steinar H. Gunderson", )
   Re: postgresql-8.0.1 performance tuning  (Cosimo Streppone, )
   Re: postgresql-8.0.1 performance tuning  ("Martin Fandel", )
   Re: postgresql-8.0.1 performance tuning  ("Martin Fandel", )
    Re: postgresql-8.0.1 performance tuning  ("Martin Fandel", )
     Re: postgresql-8.0.1 performance tuning  ("Martin Fandel", )

Martin Fandel wrote:
> Aah ok :)
>
> I've set my values now as follow (2GB RAM):
>
> SHMMAX=`cat /proc/meminfo | grep MemTotal | cut -d: -f 2 | awk '{print
> $1*1024/3}'`
> echo kernel.shmmax=${SHMMAX} >> /etc/sysctl.conf
> SHMALL=`expr ${SHMALL} / 4096 \* \( 4096 / 16 \)`
> echo kernel.shmall=${SHMALL} >> /etc/sysctl.conf
>
> sysctl.conf:
> kernel.shmmax=708329472
> kernel.shmall=44270592
>
> postgresql.conf:
> max_connections=500
> shared_buffers=40000 # ~312MB, min. 1000, max ~ 83000
>

Hmmm - shmall set to 168G... err why? Apologies for nit picking a little
- but shmall seems unreasonably high. I can't see much reason for
setting it bigger than (physical RAM in bytes)/4096 myself. So in your
case this is 2*(1024*1024*1024)/4096 = 524288

Cheers

Mark



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