Re: best arrangement of 3 disks for (insert) performance

The machine is coming from dell, and i have the option of a
PERC 3/SC RAID Controller (32MB)
or software raid.

does anyone have any experience of this controller?
its an additional £345 for this controller, i'd be interested to know what
people think - my other option is to buy the raid controller separately,
which appeals to me but i wouldnt know what to look for in a raid controller.

that raid controller review site sounds like a good idea :)

Richard.

On Friday 12 September 2003 4:24 pm, Christopher Browne wrote:
> rj(at)last(dot)fm (Richard Jones) writes:
> > I have some new hardware on the way and would like some advice on
> > how to get the most out of it..
> >
> > its a dual xeon 2.4, 4gb ram and 3x identical 15k rpm scsi disks
> >
> > should i mirror 2 of the disks for postgres data, and use the 3rd
> > disk for the o/s and the pg logs or raid5 the 3 disks or even stripe
> > 2 disks for pg and use the 3rd for o/s,logs,backups ?
> >
> > the machine will be dealing with lots of inserts, basically as many
> > as we can throw at it
>
> 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.
>
> After doing some [loose] benchmarking, the VERY best way to improve
> performance would involve a RAID controller with battery-backed cache.
>
> On a box with similar configuration to yours, it took ~3h for a
> particular set of data to load; on another one with battery-backed
> cache (and a dozen fast SCSI drives :-)), the same data took as little
> as 6 minutes to load. The BIG effect seemed to come from the
> controller.