filesystem performance

[Mark Wong]

Hi everyone,

We (PostgreSQL community) have a HP DL380 G5 that we were using to do
some very basic filesystem characterizations as part of a database
performance tuning project, so we wanted to give FreeBSD a try out of
the box.  For this set of data we used 7.1.  We're (us few that are
running the tests) are fairly unfamiliar with the community here, so
I'll be as brief as I can.  We're basically wondering if the data
we're getting out of the box is expected, and any tuning guidelines
including what changes we should expect to see in the performance.

So that said, I'll start with some of the charted results:

Scaling from 1 device to 4 devices using RAID 0:
http://207.173.203.223/~markwkm/community10/fio/freebsd-7.1/raid0-ufs.png

Comparing RAID configurations of similar capacity:
http://207.173.203.223/~markwkm/community10/fio/freebsd-7.1/capacity-ufs.png

Comparing RAID configuration using same number of drives (4):
http://207.173.203.223/~markwkm/community10/fio/freebsd-7.1/4-disk-ufs.png

All of the raw data fio output, iostat, and vmstat including charts of
some of the iostat and vmstat data are buried in here:
http://207.173.203.223/~markwkm/community10/fio/freebsd-7.1/

We used fio v1.23 to run the tests and picked parameters based on what
PostgreSQL is capable of.  The profiles used are here:
http://git.postgresql.org/gitweb?p=performance-tuning.git;a=tree;f=contrib/freebsd/fio;h=5ae97420fba010a3685c12c24cd69266d83b4daf;hb=HEAD

Hardware details are here (note we only used 4 of the internal drives
for this test, none in the MSA 70, and you may notice we have a lit of
Linux data on this page too):
http://wiki.postgresql.org/wiki/HP_ProLiant_DL380_G5_Tuning_Guide#Hardware_Details

I know I've been brief and at the same time dumped a lot of raw data.
Any pointers to tuning guides that we have obviously not seen would be
a appreciated.  We hope this data is of interest and is helpful.

Regards,
Mark