> Having WAL on a separate drive from the database would be something of
> a win. I'd buy that 1 disk for OS+WAL and then RAID [something]
> across the other two drives for the database would be pretty helpful.
Just my .02,
I did a lot of testing before I deployed our ~50GB postgresql databases
with various combinations of 6 15k SCSI drives. I did custom benchmarks
to simulate our applications, I downloaded several benchmarks, etc.
It might be a fluke, but I never got better performance with WALs on a
different disk than I did with all 6 disks in a 0+1 configuration.
Obviously that's not an option with 3 disks. =)
I ended up going with that for easier space maintenance.
Obviously YMMV, benchmark for your own situation. :)