On Fri, Nov 4, 2011 at 2:07 PM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > Before anything else, you might want to make sure you've spread your > checkpoint activity as much as possible by setting > checkpoint_completion_target = 0.9. We have shared_buffers = 2G bgwriter_delay = 1000ms effective_io_concurrency=8 synchronous_commit=off wal_buffers=16M wal_writer_delay=2000ms commit_delay=10000 checkpoint_segments=72 checkpoint_timeout=60min checkpoint_completion_target=0.8 I'm thinking bgwriter_delay and wal_writer_delay might not be working as I expected, and that maybe checkpoint_segments=72 is a bit too high, but we were having much worse I/O storms before I pushed it that high. Looking at checkpoint logging for the last few days, it goes almost always like: checkpoint complete: wrote 589 buffers (3.6%); 0 transaction log file(s) added, 0 removed, 8 recycled; write=590.325 s, sync=0.055 s, total=590.417 s 590s seems an awful lot for 589 buffers. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
