The right SHMMAX and FILE_MAX - Mailing list pgsql-performance

From Phoenix Kiula
Subject The right SHMMAX and FILE_MAX
Date
Msg-id BANLkTinCr_+Hs_zzHPb+tBdtuLFhrsfKdg@mail.gmail.com
Whole thread Raw
Responses Re: The right SHMMAX and FILE_MAX  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Re: The right SHMMAX and FILE_MAX  (Greg Smith <greg@2ndQuadrant.com>)
Re: The right SHMMAX and FILE_MAX  (Adarsh Sharma <adarsh.sharma@orkash.com>)
Re: The right SHMMAX and FILE_MAX  (Mark Kirkwood <mark.kirkwood@catalyst.net.nz>)
List pgsql-performance
Hi. I'm on a 64 Bit CentOS 5 system, quadcore processor, 8GB RAM and
tons of data storage (1 TB SATAII disks).

The current SHMMAX and SHMMIN are (commas added for legibility) --

kernel.shmmax = 68,719,476,736
kernel.shmall = 4,294,967,296

Now, according to my reading in the PG manual and this list, a good
recommended value for SHMMAX is

   (shared_buffers * 8192)

My postgresql.conf settings at the moment are:

    max_connections = 300
    shared_buffers = 300MB
    effective_cache_size = 2000MB

By this calculation, shared_b * 8192 will be:

     2,457,600,000,000

That's a humongous number. So either the principle for SHMMAX is
amiss, or I am reading this wrongly?

Similarly with "fs.file_max". There are articles like this one:
http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/chap6sec72.html

Is this relevant for PostgreSQL performance at all, or should I skip that?

Thanks for any pointers!

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