Re: High end server and storage for a PostgreSQL OLTP system

On Tue, Feb 01, 2005 at 07:35:35AM +0100, Cosimo Streppone wrote:
> >You might look at Opteron's, which theoretically have a higher data
> >bandwidth. If you're doing anything data intensive, like a sort in
> >memory, this could make a difference.
>
> Would Opteron systems need 64-bit postgresql (and os, gcc, ...)
> build to have that advantage?

Well, that would give you the most benefit, but the memory bandwidth is
still greater than on a Xeon. There's really no issue with 64 bit if
you're using open source software; it all compiles for 64 bits and
you're good to go. http://stats.distributed.net runs on a dual opteron
box running FreeBSD and I've had no issues.

> >RAID10 will be faster than RAID1.
>
> Sorry Jim, by RAID10 you mean several raid1 arrays mounted on
> different linux partitions? Or several raid1 arrays that
> build up a raid0 array? In the latter case, who decides which
> data goes in which raid1 array? Raid Adapter?

You should take a look around online for a description of raid types.

There's technically RAID0+1 and RAID1+0; one is a stripe of mirrored
drives (a RAID 0 built out of RAID 1s), the other is a mirror of two
RAID 0s. The former is much better; if you're lucky you can lose half
your drives without any data loss (if each dead drive is part of a
different mirror). Recovery is also faster.

You'll almost certainly be much happier with hardware raid instead of
software raid. stats.distributed.net runs a 3ware controller and SATA
drives.
--
Jim C. Nasby, Database Consultant               decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828

Windows: "Where do you want to go today?"
Linux: "Where do you want to go tomorrow?"
FreeBSD: "Are you guys coming, or what?"