> The main change here was discussed back in January: > http://archives.postgresql.org/message-id/4B512D0D.4030909@xxxxxxxxxxxxxxx > > What I've been doing about this is the writing leading up to > http://wiki.postgresql.org/wiki/Reliable_Writes so that when RHEL6 does > ship, we have a place to point people toward that makes it better > documented that the main difference here is a reliability improvement > rather than a performance regression. I'm not sure what else we can do > here, other than organizing more testing for kernel bugs in this area on > RHEL6. The only way to regain the majority of the "lost" performance > here is to turn off synchronous_commit in the default config. Yeah, I was looking at that. However, there seems to be some indications that there was a drop in performance specifically in 2.6.32 which went beyond fixing the reliability: http://www.phoronix.com/scan.php?page=article&item=linux_2636_btrfs&num=1 However, Phoronix doesn't say what sync option they're using; quite likely it's O_DSYNC. Unfortunately, the fact that users now need to be aware of the fsync_method again, after having it set automatically for them for the last 4 years, is a usability regression for *us*. Anything that's reasonable for us to do about it? -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
