Scott, > So do you have generally slow IO, or is it fsync behavior etc? All tests except pgBench show this system as superfast. Bonnie++ and DD tests are good (200 to 300mb/s), and test_fsync shows 14K/second. Basically it has no issues until checkpoint kicks in, at which time the entire system basically halts for the duration of the checkpoint. For that matter, if I run a pgbench and halt it just before checkpoint kicks in, I get around 12000TPS, which is what I'd expect on this system. At this point, we've tried 3.2.0.26, 3.2.0.27, 3.4.0, and tried updating the RAID driver, and changing the IO scheduler. Nothing seems to affect the behavior. Testing using Ext4 (instead of XFS) next. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
