After upgrading from 8.2 to 8.3.5, the write load on our database server has increased dramatically and inexplicably -- as has the CPU usage. Here's a Munin graph of iostat showing the sudden increase in blocks written/sec: http://purefiction.net/paste/Totals-iostatwrite1-week.png We expected the upgrade to give us better, not worse, performance. How do I diagnose this problem? The application code has not changed, and neither have the usage patterns. The number of tuple inserts/updates/deletes per second has not deviated from the normal. However, CPU usage has increased by around 30%, and the load average has similarly increased. The other performance metrics I monitor, such as transaction load, HTTP traffic, etc., show everything else as either normal or slightly decreased, as you would expect when the database server slows down. The upgrade was done with dump/restore using "pg_dump -Fc". The old database lived on a SAN volume, whereas the new database lives on a local disk volume. OS is Linux 2.6.24 on Intel (x86_64). Alexander. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
