From owner-freebsd-fs@FreeBSD.ORG Thu Nov 13 20:46:47 2008 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0613B10656A5; Thu, 13 Nov 2008 20:46:47 +0000 (UTC) (envelope-from fbsd@dannysplace.net) Received: from mail.dannysplace.net (mail.dannysplace.net [213.133.54.210]) by mx1.freebsd.org (Postfix) with ESMTP id AB6A38FC22; Thu, 13 Nov 2008 20:46:46 +0000 (UTC) (envelope-from fbsd@dannysplace.net) Received: from 203-206-171-212.perm.iinet.net.au ([203.206.171.212] helo=[192.168.10.10]) by mail.dannysplace.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1L0j5P-000L3h-Fk; Fri, 14 Nov 2008 06:46:45 +1000 Message-ID: <491C9224.4050407@dannysplace.net> Date: Fri, 14 Nov 2008 06:46:28 +1000 From: Danny Carroll User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Nikolay Denev References: <491BBF38.9010908@dannysplace.net> <200811130657.GAA26763@sopwith.solgatos.com> <20081113074301.GA13938@icarus.home.lan> <491C32BF.7020805@dannysplace.net> <04B6F041-3052-4650-BE62-817E2B28D034@gmail.com> In-Reply-To: <04B6F041-3052-4650-BE62-817E2B28D034@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Authenticated-User: danny X-Authenticator: plain X-Sender-Verify: SUCCEEDED (sender exists & accepts mail) X-Exim-Version: 4.69 (build at 08-Jul-2008 08:59:40) X-Date: 2008-11-14 06:46:43 X-Connected-IP: 203.206.171.212:1163 X-Message-Linecount: 34 X-Body-Linecount: 18 X-Message-Size: 1416 X-Body-Size: 608 X-Received-Count: 1 X-Recipient-Count: 5 X-Local-Recipient-Count: 5 X-Local-Recipient-Defer-Count: 0 X-Local-Recipient-Fail-Count: 0 X-SA-Exim-Connect-IP: 203.206.171.212 X-SA-Exim-Rcpt-To: ndenev@gmail.com, koitsu@FreeBSD.org, freebsd-fs@freebsd.org, freebsd@sopwith.solgatos.com, freebsd-hardware@freebsd.org X-SA-Exim-Mail-From: fbsd@dannysplace.net X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on ferrari.dannysplace.net X-Spam-Level: X-Spam-Status: No, score=0.2 required=8.0 tests=ALL_TRUSTED,AWL,TVD_RCVD_IP autolearn=disabled version=3.2.5 X-SA-Exim-Version: 4.2 X-SA-Exim-Scanned: Yes (on mail.dannysplace.net) Cc: freebsd-fs@freebsd.org, Jeremy Chadwick , Dieter , freebsd-hardware@freebsd.org Subject: Re: Areca vs. ZFS performance testing. X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: fbsd@dannysplace.net List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Nov 2008 20:46:47 -0000 Nikolay Denev wrote: > I think some RAID controllers do not use the cache when you export the > disks as pass-thru/jbod, I assumed this is the case but now I am not so sure. > but on some controllers you can workaround this by making > every disk a RAID0(stripe) array with only one disk. > Dunno if that would work on the areca... You can probably do that with this as controller as well. However if I look at the manual I do not see an option to disable the cache for Raid sets. Only to change it from Write-back to Write-Through. I guess write-through is *almost* as if the cache is disabled. -D