Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id E77709FBFB8 for ; Fri, 10 Aug 2007 01:59:07 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 89417-08 for ; Fri, 10 Aug 2007 01:59:02 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from noel.decibel.org (noel.decibel.org [67.100.216.10]) by postgresql.org (Postfix) with ESMTP id 7F85D9FBFA5 for ; Fri, 10 Aug 2007 01:59:03 -0300 (ADT) Received: by noel.decibel.org (Postfix, from userid 1001) id 7043856473; Thu, 9 Aug 2007 23:59:00 -0500 (CDT) Received: (hashcash-sendmail, from uid 1001); Thu, 9 Aug 2007 23:58:58 -0500 Date: Thu, 9 Aug 2007 23:58:58 -0500 From: Decibel! To: Scott Marlowe Cc: pgsql-performance@postgresql.org Subject: Re: Dell Hardware Recommendations Message-ID: <20070810045857.GL20424@nasby.net> References: <46BB6F3D.6090608@gmail.com> <20070809220502.GE20424@nasby.net> <20070809224138.GI20424@decibel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0zAvg8I2HpXbmZ+A" Content-Disposition: inline In-Reply-To: X-Operating-System: FreeBSD 6.1-RELEASE-p10 amd64 X-Distributed: Join the Effort! http://www.distributed.net User-Agent: Mutt/1.5.13 (2006-08-11) X-Hashcash: 1:20:070810:scott.marlowe@gmail.com::oJtO31vlMlullXyi:00000000000000 000000000000000000000000A6QJ X-Hashcash: 1:20:070810:pgsql-performance@postgresql.org::Mw3w25asq+5qif++:00000 0000000000000000000000001oR2 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200708/94 X-Sequence-Number: 26224 --0zAvg8I2HpXbmZ+A Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 09, 2007 at 08:58:19PM -0500, Scott Marlowe wrote: > > On Thu, Aug 09, 2007 at 05:29:18PM -0500, Scott Marlowe wrote: > > > On 8/9/07, Decibel! wrote: > > > > > > > Also, a good RAID controller can spread reads out across both drive= s in > > > > each mirror on a RAID10. Though, there is an argument for not doing > > > > that... it makes it much less likely that both drives in a mirror w= ill > > > > fail close enough to each other that you'd lose that chunk of data. > > > > > > I'd think that kind of failure mode is pretty uncommon, unless you're > > > in an environment where physical shocks are common. which is not a > > > typical database environment. (tell that to the guys writing a db for > > > a modern tank fire control system though :) ) You'd be surprised. I've seen more than one case of a bunch of drives failing within a month, because they were all bought at the same time. > > > > while with RAID10 you can > > > > potentially lose half the array without losing any data. > > > > > > Yes, but the RIGHT two drives can kill EITHER RAID 5 or RAID10. Sure, but the odds of that with RAID5 are 100%, while they're much less in a RAID10. > > > While I agree with Merlin that for OLTP a faster drive is a must, for > > > OLAP, more drives is often the real key. The high aggregate bandwidth > > > of a large array of SATA drives is an amazing thing to watch when > > > running a reporting server with otherwise unimpressive specs. True. In this case, the OP will probably want to have one array for the OLTP stuff and one for the OLAP stuff. --=20 Decibel!, aka Jim Nasby decibel@decibel.org EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) --0zAvg8I2HpXbmZ+A Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.3 (FreeBSD) iD8DBQFGu/CRdO30qud8SkgRAtmTAJ9/RW6LDs2LILyXI5yVZ/H4Ah5dWwCghuWx QSLEuIvugdyML2ASL1CHXvY= =V+X3 -----END PGP SIGNATURE----- --0zAvg8I2HpXbmZ+A--