bofh wrote:
Hi all,
I'm looking at a project that I'm trying to run on openbsd. All that
box will have is postgresql. At this time, it's just 2 programmers
and 1 sysadmin type person that's involved, no DBAs, so apologies if
the questions are... too simplistic.
And I realize if I want to maximize performance, I need to examine
OSes as well. But at this point, I want to explore what is the
biggest postgresql server I can run under openbsd. If at all
possible, I want to run everything in memory.
What I'm looking for is what is the biggest database I can run on a 4
socket (4 core per socket) AMD motherboard with 64GB or 128GB of Ram
using a standard kernel?
For example, what should shmmax be set to?
http://developer.postgresql.org/pgdocs/postgres/kernel-resources.html
recommends several hundred megabytes.
I understand I may need to recompile the kernel. Any recommendations
for something that can run on 64/128GB ram, 16 cpus, running only
postgresql?
Thanks in advance. I'm exploring what is possible at this point. I
realize I haven't given out more information, but I don't have that in
hand yet. But I'm interested in finding out what my top end is.
Thanks!
I couldn't tell you how big it can go, but to give you some idea of
resources needed and tuning options, take a look at
http://www.network-theory.co.uk/docs/postgresql/vol3/SharedMemoryandSemaphores.html
As well as discussing how to tune kernel parameters to give enough
resources for a given number of concurrent Postgres connections, it
describes how to set those parameters on a variety of OSes, including
specifics for OpenBSD.
Dave W.
