From: | Balkrishna Sharma <b_ki(at)hotmail(dot)com> |
---|---|
To: | <pgsql-admin(at)postgresql(dot)org> |
Subject: | Relation between RAM / shmmax / shmall / shared_buffers |
Date: | 2010-05-25 18:05:11 |
Message-ID: | BAY149-w5102A9288345674F2C689AF0E80@phx.gbl |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-admin |
Hi,
I am having a transactional database heavy on parallel reads and updates. Apart from hardware optimization, I want to ensure that my system parameters are optimized as well. Following is what I am doing on my test system having 4GB RAM. Please let me know if the logic sounds ok (at least at high-level) and if there are other related parameters I should tweak as well:
RAM = 4GB1. Keeping the kernel parameter kernel.shmmax at 75% of RAM (i.e. at 3GB )kernel.shmmax = 32212254722. Keeping the kernel parameter shmall at the same value. Because shmall is measured in number of pages and each page on my linux is 4096 bytes, having kernel.shmall = 786432 (786432 * 4096 = 3221225472, same as shmmax)3. Keeping the shared_buffer parameter in the postgresql.conf file to be 25% of the kernel.shmmax. i.e. shared_buffers = 768MB (25% of 3072 MB)
Thanks,-Bala
_________________________________________________________________
The New Busy is not the old busy. Search, chat and e-mail from your inbox.
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_3
From | Date | Subject | |
---|---|---|---|
Next Message | Kevin Grittner | 2010-05-25 18:10:06 | Re: Relation between RAM / shmmax / shmall / shared_buffers |
Previous Message | Balkrishna Sharma | 2010-05-25 18:01:22 | Re: How to find if a SELECT is reading from buffer or disk ? |