Hi all, I started to do some performance tests (using pgbench) in order to estimate the DRBD impact on our servers, my plan was to perform some benchmarks without DRBD in order to compare the same benchmark with DRBD. I didn't perform yet the benchmark with DRBD and I'm already facing something I can not explain (I performed at the moment only reads test).
I'm using postgres 8.2.3 on Red Hat compiled with GCC 3.4.6. I'm using pgbench with scaling factor with a range [1:500], my server has 4 cores so I'm trying with 16 client and 4000 transaction per client: pgbench -t 4000 -c 16 -S db_perf. I did 3 session using 3 different values of shared_buffers: 64MB, 256MB, 512MB and my server has 2GB. The following graph reports the results: http://img84.imageshack.us/my.php?image=totalid7.png as you can see using 64MB as value for shared_buffers I'm obtaining better results. Is this something expected or I'm looking in the wrong direction? I'm going to perform same tests without using the -S option in pgbench but being a time expensive operation I would like to ear your opinion first. Regards Gaetano Mendola -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
