From owner-freebsd-questions@FreeBSD.ORG Mon Jul 13 20:59:04 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2D20F1065673 for ; Mon, 13 Jul 2009 20:59:04 +0000 (UTC) (envelope-from freebsd@rgbaz.eu) Received: from jasper.secsrv.net (jasper.secsrv.net [66.98.138.37]) by mx1.freebsd.org (Postfix) with ESMTP id 07C068FC1C for ; Mon, 13 Jul 2009 20:59:03 +0000 (UTC) (envelope-from freebsd@rgbaz.eu) Received: from [82.161.18.200] (helo=[10.0.1.104]) by jasper.secsrv.net with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.63) (envelope-from ) id 1MQSc1-00050m-4s; Mon, 13 Jul 2009 16:59:01 -0400 Message-Id: From: FBSD UG To: Maxim Khitrov In-Reply-To: <26ddd1750907131223k9e20142n1fbc41e16d82bf87@mail.gmail.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v935.3) Date: Mon, 13 Jul 2009 22:58:53 +0200 References: <937260.17107.qm@web51002.mail.re2.yahoo.com> <26ddd1750907131223k9e20142n1fbc41e16d82bf87@mail.gmail.com> X-Mailer: Apple Mail (2.935.3) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - jasper.secsrv.net X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - rgbaz.eu X-Source: X-Source-Args: X-Source-Dir: Cc: Free BSD Questions list , mahlerrd@yahoo.com Subject: Re: ZFS or UFS for 4TB hardware RAID6? 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: Mon, 13 Jul 2009 20:59:04 -0000 > >> A bit of reading shows that ZFS, if it's stable enough, has some >> really great features that would be nice on such a large pile o' >> drives. >> >> See http://wiki.freebsd.org/ZFSQuickStartGuide >> >> I guess the last question I'll ask (as any more may uncover my >> ignorance) is if you need to use hardware RAID at all? It seems >> both UFS2 and ZFS can do software RAID which seems to be quite >> reasonable with respect to performance and in many ways seems to be >> more robust since it is a bit more portable (no specialized >> hardware). > > I've thought about this one a lot. In my case, the hard drives are in > a separate enclosure from the server and the two had to be connected > via SAS cables. The 9690SA-8E card was the best choice I could find > for accessing an external SAS enclosure with support for 8 drives. > > I could configure it in JBOD mode and then use software to create a > RAID array. In fact, I will likely do this to compare performance of a > hardware vs. software RAID5 solution. The ZFS RAID-Z option does not > appeal to me, because the read performance does not benefit from > additional drives, and I don't think RAID6 is available in software. > For those reasons I'm leaning toward a hardware implementation. > Hi Maxim, RAID-Z2 is the RAID6 double parity option in ZFS. gr Arno