From owner-freebsd-stable@FreeBSD.ORG Thu Nov 9 11:59:39 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AA64416A415 for ; Thu, 9 Nov 2006 11:59:39 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from mail.ticketswitch.com (mail.ticketswitch.com [194.200.93.188]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4334443D5D for ; Thu, 9 Nov 2006 11:59:38 +0000 (GMT) (envelope-from petefrench@ticketswitch.com) Received: from [172.16.1.6] (helo=dilbert.firstcallgroup.co.uk) by mail.ticketswitch.com with esmtp (Exim 4.60 (FreeBSD)) (envelope-from ) id 1Gi8ZF-000PJj-0Z; Thu, 09 Nov 2006 11:59:37 +0000 Received: from petefrench by dilbert.firstcallgroup.co.uk with local (Exim 4.61 (FreeBSD)) (envelope-from ) id 1Gi8ZC-000Dgf-QH; Thu, 09 Nov 2006 11:59:34 +0000 To: ivoras@fer.hr In-Reply-To: <455314B8.7080104@fer.hr> Message-Id: From: Pete French Date: Thu, 09 Nov 2006 11:59:34 +0000 Cc: freebsd-stable@freebsd.org Subject: Re: Dissapointing performance of ciss RAID 0+1 ? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Nov 2006 11:59:39 -0000 > > Raw dd gives 50 meg/second > On /dev/da1, with a reasonable block size (1m)? Block size is 2meg. I was using da1s1 and da1s2 which were giving me 50 and 47 meg/second resepctively - if I switch to da1 on it's own I get 59 meg/second. reading from the filesystem with the vfs.read_max set to 64 I now get 112 meg/second though ?!!! how can the filesystem give me better performance than the raw device ? I do not think this is a caching issue as I am using a test file nearly twice the size of the RAM in the system to get round this. I am delighted by the performance increase, but the results do not make sense. -pete.