Thread

1. Re: Upper limit on number of buffers?

   Joe Conway <joe@conway-family.com> — 2000-12-25T04:20:33Z

    > * mlw <markw@mohawksoft.com> [001224 18:06] wrote:
    > > This line works:
    > > /usr/local/pgsql/bin/postmaster -N 32 -B 928 -i -S
    > > -D/home/postgres/pgdev -o "-F -fs -S 4096"
    > >
    > > Where as this line:
    > >
    > > /usr/local/pgsql/bin/postmaster -N 32 -B 1024 -i -S
    > > -D/home/postgres/pgdev -o "-F -fs -S 4096"
    > >
    > > does not.
    > >
    > > Any ideas?
    > > I have 256M of memory, RedHat Linux 7.0, CVS version of Postgres as of
   a
    > > couple days ago.
    >
    > I'm just going to guess that you need to consult your OS's
    > documentation and figure out how to raise the amount of system V
    > shared memory available.
   
    I think Alfred is probably correct. I've run into this before myself. See
   the following link:
   
   
   http://www.postgresql.org/devel-corner/docs/admin/kernel-resources.htm#SYSVI
   PC
   
    The relevant section reads:
   
    Linux
   
    The default shared memory limit (both SHMMAX and SHMALL) is 32 MB in 2.2
   kernels, but it can be changed in the proc file system (without reboot). For
   example, to allow 128 MB:
   
    $ echo 134217728 >/proc/sys/kernel/shmall
   $ echo 134217728 >/proc/sys/kernel/shmmax
   You could put these commands into a script run at boot-time.
   
    Other parameters are sufficiently sized for any application. If you want to
    see for yourself look into /usr/src/linux/include/asm-xxx/shmparam.h and
    /usr/src/linux/include/linux/sem.h.
   
    Hope this helps,
   
    Joe
   
   
   
   
   

2. Re: Upper limit on number of buffers?

   Michael J Schout <mschout@gkg.net> — 2000-12-29T17:29:21Z

   On Sun, 24 Dec 2000, Joe Conway wrote:
   
   >  Linux
   > 
   >  The default shared memory limit (both SHMMAX and SHMALL) is 32 MB in 2.2
   > kernels, but it can be changed in the proc file system (without reboot). For
   > example, to allow 128 MB:
   > 
   >  $ echo 134217728 >/proc/sys/kernel/shmall
   > $ echo 134217728 >/proc/sys/kernel/shmmax
   > You could put these commands into a script run at boot-time.
   
   On redhat 6.2 I know that you can use /etc/sysctl.conf to do this as well.
   
   Just add this to /etc/sysctl.conf.
   
   kernel.shmall = 134217728
   kernel.shmmax = 134217728
   
   After this, your tunables will be restored every time that the system boots.
   
   Mike
   
   
   

3. Re: Upper limit on number of buffers?

   Andrew McMillan <andrew@catalyst.net.nz> — 2000-12-31T22:18:03Z

   Michael J Schout wrote:
   > 
   > On Sun, 24 Dec 2000, Joe Conway wrote:
   > 
   > On redhat 6.2 I know that you can use /etc/sysctl.conf to do this as well.
   > 
   > Just add this to /etc/sysctl.conf.
   > 
   > kernel.shmall = 134217728
   > kernel.shmmax = 134217728
   > 
   > After this, your tunables will be restored every time that the system boots.
   
   I can confirm that that applies under Debian as well, although there is
   also some stuff in the startup script for Debian to configure files max
   specifically for PostgreSQL.
   
   Cheers,
   				Andrew.
   -- 
   _____________________________________________________________________
              Andrew McMillan, e-mail: Andrew@catalyst.net.nz
   Catalyst IT Ltd, PO Box 10-225, Level 22, 105 The Terrace, Wellington
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