From: | Greg Smith <greg(at)2ndquadrant(dot)com> |
---|---|
To: | Janning <ml(at)planwerk6(dot)de> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Write performance |
Date: | 2010-06-24 13:57:50 |
Message-ID: | 4C23645E.5070101@2ndquadrant.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
As others have already pointed out, your disk performance here is
completely typical of a single pair of drives doing random read/write
activity. So the question you should be asking is how to reduce the
amount of reading and writing needed to run your application. The
suggestions at
http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server address
that. Increases to shared_buffers and checkpoint_segments in particular
can dramatically reduce the amount of I/O needed to run an application.
On the last server I turned, random reads went from a constant stream of
1MB/s (with default value of shared_buffers at 32MB) to an average of
0.1MB/s just by adjusting those two parameters upwards via those guidelines.
If you haven't already made large increases to those values, I'd suggest
starting there before presuming you must get a different disk setup.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.us
From | Date | Subject | |
---|---|---|---|
Next Message | Anj Adu | 2010-06-24 14:55:04 | Re: WAL+Os on a single disk |
Previous Message | Janning Vygen | 2010-06-24 13:45:31 | Re: Write performance |