Re: How to setup disk spindles for best performance

On Wed, Aug 20, 2008 at 4:25 PM, Christiaan Willemsen
<cwillemsen(at)technocon(dot)com> wrote:
> I'm currently trying to find out what the best configuration is for our new
> database server. It will server a database of about 80 GB and growing fast.
> The new machine has plenty of memory (64GB) and 16 SAS disks, of wich two
> are already in use as a mirror for the OS.

Got almost the same setup with 32 Gig of ram... I'm running the Areca
1680 controller with 512M battery backed cache and I'm quite happy
with the performance so far.

Mine is set up to use the OS mirror set for the pg_xlog as well, but
on a separate logical partition. I figure the RAID controller will
even out the writes there to keep it fast. The next 12 drives are a
RAID-10 set and the last two are hot spares. On an array this big you
should always have at least one hot spare.

Generally breaking the disks up for index versus tables etc is a lot
of work for minimal gain. A good RAID controller will make up for
having to do that, and usually do better, since if the indexes are
getting hit a LOT then you have all 12 disks in the RAID-10 working
together.

But what's your workload look like? Lotsa updates, inserts, deletes,
big selects, bulk loads in the middle of the day, etc...?