From owner-freebsd-questions@FreeBSD.ORG Fri May 30 17:18:54 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id EDD2A24D for ; Fri, 30 May 2014 17:18:54 +0000 (UTC) Received: from wonkity.com (wonkity.com [67.158.26.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "wonkity.com", Issuer "wonkity.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id A04472C46 for ; Fri, 30 May 2014 17:18:54 +0000 (UTC) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.14.8/8.14.8) with ESMTP id s4UHIrah008375 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 30 May 2014 11:18:53 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.14.8/8.14.8/Submit) with ESMTP id s4UHIrT4008372; Fri, 30 May 2014 11:18:53 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Fri, 30 May 2014 11:18:53 -0600 (MDT) From: Warren Block To: Matthew Seaman Subject: Re: ZFS Recommendations for a new server In-Reply-To: <5388B5BE.6050609@infracaninophile.co.uk> Message-ID: References: <5388B5BE.6050609@infracaninophile.co.uk> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (wonkity.com [127.0.0.1]); Fri, 30 May 2014 11:18:53 -0600 (MDT) Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 May 2014 17:18:55 -0000 On Fri, 30 May 2014, Matthew Seaman wrote: > On 05/30/14 16:11, Alejandro Imass wrote: >> The new server has a 2 x 1TB RE4 3ware 9650SE RAID and I have friends that >> tell me is actually better to use ZFS RAID instead of HW RAID1. Is this >> true? Why so? > > I recently had a similar setup using an old 3ware RAID card, which we > upgraded to 4TB drives .... and then had to ditch the 3ware card and > replace it with a LSI HBA because the 3ware card didn't recognise > anything beyond the first 2TB or the drives. > > Yes, you want to use ZFS RAID rather than putting ZFS onto a single > virtual drive presented by your RAID controller. ZFS does all the > resilience and patrol read^W^Wzpool scrubbing and disk IO caching and > stuff using your system's main RAM and CPUs which are generally a lot > more capable than any RAID controller. Plus ZFS does it better -- > 'punctured stripe' is not something that happens to ZFS for instance. Another way to explain this is that ZFS makes the computer itself into a RAID controller, only with more resources and much more development of the "firmware".