From owner-freebsd-hardware@FreeBSD.ORG Mon Nov 17 23:46:17 2008 Return-Path: Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6EE2D1065672; Mon, 17 Nov 2008 23:46:17 +0000 (UTC) (envelope-from danny@dannysplace.net) Received: from mail.dannysplace.net (mail.dannysplace.net [213.133.54.210]) by mx1.freebsd.org (Postfix) with ESMTP id 1BBF58FC08; Mon, 17 Nov 2008 23:46:17 +0000 (UTC) (envelope-from danny@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 1L2DnK-000BND-3e; Tue, 18 Nov 2008 09:46:16 +1000 Message-ID: <49220238.2040507@dannysplace.net> Date: Tue, 18 Nov 2008 09:46:00 +1000 From: Danny Carroll User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Matt Simerson References: <490A782F.9060406@dannysplace.net> <20081031033208.GA21220@icarus.home.lan> <490A849C.7030009@dannysplace.net> <20081031043412.GA22289@icarus.home.lan> <490A8FAD.8060009@dannysplace.net> <491BBF38.9010908@dannysplace.net> <491C5AA7.1030004@samsco.org> <491C9535.3030504@dannysplace.net> <4920E1DD.7000101@dannysplace.net> <492158D2.5020506@dannysplace.net> In-Reply-To: X-Enigmail-Version: 0.95.7 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: 2008-11-18 09:46:14 X-Connected-IP: 203.206.171.212:1113 X-Message-Linecount: 36 X-Body-Linecount: 22 X-Message-Size: 1993 X-Body-Size: 959 X-Received-Count: 1 X-Recipient-Count: 3 X-Local-Recipient-Count: 3 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: matt@corp.spry.com, freebsd-fs@freebsd.org, freebsd-hardware@freebsd.org X-SA-Exim-Mail-From: danny@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, freebsd-hardware@freebsd.org Subject: Re: Areca vs. ZFS performance testing. X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Nov 2008 23:46:17 -0000 Matt Simerson wrote: > Disk caching is a completely different animal, and one which I didn't > mention. I'm spoke only about the write cache on the controller. Mine > all arrived off by default, which is a VERY reasonable default > configuration. Page 97 of the manual says about it: Ahhh, no I was talking about the disk cache setting. That is the one that is set to on by default (at least for me). I find it strange that this is the case. IMHO it makes the idea of a Battery backed cache redundant. > Perhaps it's model specific, or your vendor configured it that way. Or > you got a return that someone else monkeyed with. I'm not going to speak > for Areca but it seems quite odd that Areca would ship them with the > cache enabled. I've used many hundreds of RAID controllers over the > years and without exception, every single one with a write cache had it > disabled by default. I guess I had a return model. It's not really a big deal. -D