Luke,
Here's some background:
I use Pg 7.4.13 (I've tested as far back as 7.4.8). I use an 8GB data with a program called odbc-bench. I run an 18 minute test. With each run, HP box excluded, I unmount the discs involved, reformat, un-tar the backup of PGDATA and pg_xlog back on the discs, start-up Postgresql, then run the odbc-bench.
On the Sun box, I've benchmarked an average of 3 to 4 runs with each disc (up to 8) in succession in RAID0, RAID5, and RAID10 where applicable. I've done with with pg_xlog on the same discs as PGDATA and separately, so I've felt like I had a good understanding of how the performance works. I've notice performance seems to level off at around 6 discs with another 10-15% with two more discs.
When I run odbc-bench, I also run vmstat in the background (through a python script) which averages/summarzies the high/low/average of each category for each minute then a final summary after the run.
On the Sun box, with 4 discs (RAID10) to one channel on the LSI RAID card, I see an average TPS around 70. If I ran this off of one disc, I see an average TPS of 32.
on the HP box, with 6-discs in RAID10 and 1 spare. I see a TPS of 34. I don't have my vmstat reports with me, but I recall the CPU utilitization on the HP was about 50% higher. I need to check on this.
Steve
On 8/8/06, Luke Lonergan <llonergan@greenplum.com> wrote: Steve,
On 8/8/06 8:01 AM, "Steve Poe" <steve.poe@gmail.com> wrote:
> Thanks for the feedback. I use the same database test that I've run a Sun
> dual Opteron with 4Gb RAM and (2) four disk arrays in RAID10. The sun box with
> one disc on an LSI MegaRAID 2-channel adapter outperforms this HP box. I
> though I was doing something wrong or there is something wrong with the box.
Given the circumstances (benchmarked I/O is great, comparable perf on
another box with single disk is better), seems that one of:
1) something wrong with the CPU/memory on the box
2) something with the OS version / kernel
3) something with the postgres configuration
Can you post the database benchmark results?
- Luke
