X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 450769DD539 for ; Tue, 21 Mar 2006 07:49:37 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 50573-08 for ; Tue, 21 Mar 2006 07:49:39 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from noel.decibel.org (noel.decibel.org [67.100.216.10]) by postgresql.org (Postfix) with ESMTP id BE4449DCA0F for ; Tue, 21 Mar 2006 07:49:34 -0400 (AST) Received: by noel.decibel.org (Postfix, from userid 1001) id 2E01F56435; Tue, 21 Mar 2006 05:49:38 -0600 (CST) Received: (hashcash-sendmail, from uid 1001); Tue, 21 Mar 2006 05:49:37 -0600 Date: Tue, 21 Mar 2006 05:49:37 -0600 From: "Jim C. Nasby" To: Luke Lonergan Cc: Miguel , Postgresql Performance Subject: Re: Best OS & Configuration for Dual Xeon w/4GB & Message-ID: <20060321114937.GL15742@pervasive.com> References: <441F1AC5.9050700@123.com.sv> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: FreeBSD 6.0-RELEASE-p4 amd64 X-Distributed: Join the Effort! http://www.distributed.net User-Agent: Mutt/1.5.11 X-Hashcash: 1:20:060321:llonergan@greenplum.com::7pKSiwCan+EIwOk1:00000000000000 0000000000000000000000000o6p X-Hashcash: 1:20:060321:mmiranda@123.com.sv::fGm02UXCh5HOpl/z:000000000000000000 0000000000000000000000004Ag+ X-Hashcash: 1:20:060321:pgsql-performance@postgresql.org::4ca0aMTtdlufSnhF:00000 0000000000000000000000002iQG X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.108 required=5 tests=[AWL=0.108] X-Spam-Score: 0.108 X-Spam-Level: X-Archive-Number: 200603/384 X-Sequence-Number: 17821 On Mon, Mar 20, 2006 at 01:27:56PM -0800, Luke Lonergan wrote: > >> Transfer rates: > >> outside: 102400 kbytes in 2.075984 sec = 49326 kbytes/sec > >> middle: 102400 kbytes in 2.100510 sec = 48750 kbytes/sec > >> inside: 102400 kbytes in 2.042313 sec = 50139 kbytes/sec > >> > > I have 6 ultra a320 72G 10k discs > > Yah - ouch. With 6 drives in a RAID10, you should expect 3 drives worth of > sequential scan performance, or anywhere from 100MB/s to 180MB/s. You're > getting from half to 1/3 of the performance you'd get with a decent raid > controller. > > If you add a simple SCSI adapter like the common LSI U320 adapter to your > DL380G3 and then run software RAID, you will get more than 150MB/s with less > CPU consumption. I'd also expect you'd get down to about 2ms access times. FWIW, here's my dirt-simple workstation, with 2 segate SATA drives setup as a mirror using software (first the mirror, then one of the raw drives): decibel@noel.2[5:43]~:15>sudo diskinfo -vt /dev/mirror/gm0 Password: /dev/mirror/gm0 512 # sectorsize 300069051904 # mediasize in bytes (279G) 586072367 # mediasize in sectors Seek times: Full stroke: 250 iter in 1.416409 sec = 5.666 msec Half stroke: 250 iter in 1.404503 sec = 5.618 msec Quarter stroke: 500 iter in 2.887344 sec = 5.775 msec Short forward: 400 iter in 2.101949 sec = 5.255 msec Short backward: 400 iter in 2.373578 sec = 5.934 msec Seq outer: 2048 iter in 0.209539 sec = 0.102 msec Seq inner: 2048 iter in 0.347499 sec = 0.170 msec Transfer rates: outside: 102400 kbytes in 3.183924 sec = 32162 kbytes/sec middle: 102400 kbytes in 3.216232 sec = 31838 kbytes/sec inside: 102400 kbytes in 4.242779 sec = 24135 kbytes/sec decibel@noel.2[5:43]~:16>sudo diskinfo -vt /dev/ad4 /dev/ad4 512 # sectorsize 300069052416 # mediasize in bytes (279G) 586072368 # mediasize in sectors 581421 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. Seek times: Full stroke: 250 iter in 5.835744 sec = 23.343 msec Half stroke: 250 iter in 4.364424 sec = 17.458 msec Quarter stroke: 500 iter in 6.981597 sec = 13.963 msec Short forward: 400 iter in 2.157210 sec = 5.393 msec Short backward: 400 iter in 2.330445 sec = 5.826 msec Seq outer: 2048 iter in 0.181176 sec = 0.088 msec Seq inner: 2048 iter in 0.198974 sec = 0.097 msec Transfer rates: outside: 102400 kbytes in 1.715810 sec = 59680 kbytes/sec middle: 102400 kbytes in 1.937027 sec = 52865 kbytes/sec inside: 102400 kbytes in 3.260515 sec = 31406 kbytes/sec No, I don't know why the transfer rates for the mirror are 1/2 that as the raw device. :( -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461