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 0FEB09DC848 for ; Fri, 24 Feb 2006 20:33:54 -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 25452-09 for ; Fri, 24 Feb 2006 20:33:57 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from linda-3.paradise.net.nz (bm-3a.paradise.net.nz [203.96.152.182]) by postgresql.org (Postfix) with ESMTP id 071069DC814 for ; Fri, 24 Feb 2006 20:33:51 -0400 (AST) Received: from smtp-1.paradise.net.nz (tclsnelb1-src-1.paradise.net.nz [203.96.152.172]) by linda-3.paradise.net.nz (Paradise.net.nz) with ESMTP id <0IV7008GGW77AH@linda-3.paradise.net.nz> for pgsql-performance@postgresql.org; Sat, 25 Feb 2006 13:33:27 +1300 (NZDT) Received: from [192.168.1.11] (218-101-28-207.dsl.clear.net.nz [218.101.28.207]) by smtp-1.paradise.net.nz (Postfix) with ESMTP id 16F761424D09; Sat, 25 Feb 2006 13:29:58 +1300 (NZDT) Date: Sat, 25 Feb 2006 13:29:55 +1300 From: Mark Kirkwood Subject: Re: Reliability recommendations In-reply-to: To: Luke Lonergan Cc: "Joshua D. Drake" , "Craig A. James" , pgsql-performance@postgresql.org Message-id: <43FFA503.5070700@paradise.net.nz> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Accept-Language: en-us, en User-Agent: Mozilla Thunderbird 1.0.6 (X11/20051106) References: X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.195 required=5 tests=[AWL=0.195] X-Spam-Score: 0.195 X-Spam-Level: X-Archive-Number: 200602/397 X-Sequence-Number: 17383 Luke Lonergan wrote: > > I'd be more shocked if this weren't also true of nearly all SCSI HW RAID > adapters of this era. If you had ordered an HP DL380 server you'd get about > the same performance. > > BTW - I don't think there's anything reasonable about 50-55 MB/s from 6 > disks, I'd put the minimum for this era machine at 5 x 30 = 150MB/s. > He was quoting for 6 disk RAID 10 - I'm thinking 3 x 30MB/s = 90MB/s is probably more correct? Having aid that, your point is still completely correct - the performance @55MB/s is poor (e.g. my *ata* system with 2 disk RAID0 does reads @110MB/s). cheers Mark