From owner-freebsd-questions@FreeBSD.ORG Wed Jun 28 22:25:11 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 04A4016A4B3 for ; Wed, 28 Jun 2006 22:25:10 +0000 (UTC) (envelope-from lists@stringsutils.com) Received: from zoraida.natserv.net (p65-147.acedsl.com [66.114.65.147]) by mx1.FreeBSD.org (Postfix) with ESMTP id E2E564424A for ; Wed, 28 Jun 2006 22:22:09 +0000 (GMT) (envelope-from lists@stringsutils.com) Received: from zoraida.natserv.net (localhost.natserv.net [127.0.0.1]) by zoraida.natserv.net (Postfix) with ESMTP id 83783B894; Wed, 28 Jun 2006 18:22:04 -0400 (EDT) Received: from zoraida.natserv.net (zoraida.natserv.net [66.114.65.147]) by zoraida.natserv.net (Postfix) with ESMTP id 4D86CB88E; Wed, 28 Jun 2006 18:22:04 -0400 (EDT) References: <20060620060845.U1114@ganymede.hub.org> <20060621183832.H1114@ganymede.hub.org> <20060621195523.I1114@ganymede.hub.org> Message-ID: X-Mailer: http://www.courier-mta.org/cone/ From: Francisco Reyes To: Nikolas Britton Date: Wed, 28 Jun 2006 18:22:04 -0400 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="US-ASCII" Content-Disposition: inline Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV using ClamSMTP X-Mailman-Approved-At: Wed, 28 Jun 2006 23:36:25 +0000 Cc: Marc =?ISO-8859-1?B?Ry4=?= Fournier , Atom Powers , Ted Mittelstaedt , chad@shire.net, freebsd-questions@freebsd.org Subject: Re: Are hardware vendors starting to bail on FreeBSD ... ? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Jun 2006 22:25:11 -0000 Nikolas Britton writes: >> Dont get me wrong.. I can get approval to go SCSI since our >> machines need at least 1T+ (the storage machines) err.. should have say "can't get approval" to go SCSI.. We are using SATA. > Why? 1TB and up is a SATA niche. Correct.. that is what we use. > You can buy 3 SATA arrays for the price of 1 SCSI array Yup. SCSI drives are 3 to 5 times more expensive than SATA. >.... Also... gigabit Ethernet is only 125MB/s > (Max) and and a single SATA drive can easily transfer at 50MB/s*. But RAID can possibly do more than 125MB/sec if doing large sequential files.. When I last tested on a 100Mb switch vs a 1000Mb switch, the performance difference in our case (rsyncing data from Maildir) was around 25% to 30% as measured over a week. And this is mostly lots and lots of small files. That tells me that even with SATA we are able to go over the 100Mb limit. 8 Disks in RAID 10, with 2 hot spares. > limiting factor is probably going to be your bus with arrays/GigE so > SCSI is pointless unless you can take advantage of SCSI's TCQ with > high random access I/O loads If we could afford it I still think SCSI would be usefull. It is not only about raw throughput, but how quickly you can get the data to the apps or to disk. Specially in a database or Maildir enviroment where there is lots of I/O going on. > *I just tested this with two Maxtor SATA drives the other day: > dd if=/dev/disk1 of=/dev/disk2 bs=4m. It dropped off to about 30MB/s > at the end but my average read/write was just over 50MB/s. But that is mostly sequential work.. I think for sequential work SATA is definitely the way to go.. is when you get into the random I/O that supposedly SCSI outshines SATA.