Database Server Tuning

I sent this to the admin list the other day and got no responses. Maybe this
list can give me some pointers.

Hello

I am working on installing and configuring a Postgres database
server. I am running Redhat Enterprise ES 3.0 and Redhat Database 3.0.
"Postgres version 7.3.4-11". This server will host 150-200 users. There will
be about 9 databases in our cluster ranging anywhere from 500MB to 3GB The
hardware is a dual Xeon running at 2.8GHZ, 4GB RAM, Ultra 320 SCSI hard
drives running on Adaptec Ultra Raid Controllers.
I am planning on separating the OS, Data, WAL on to separate drives
which will be mirrored. I am looking for input on setting kernel parameters,
and Postgres server runtime parameters and other settings relating to
tuning. Also is there any benchmarking tools available that will help me
tune this server.

Thanks

John Allgood - ESC
System Administrator
770.535.5049