From owner-freebsd-questions@freebsd.org Thu Aug 4 04:49:29 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 59FB2BAD0D8 for ; Thu, 4 Aug 2016 04:49:29 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from holgerdanske.com (holgerdanske.com [184.105.128.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.he.net", Issuer "GeoTrust SSL CA - G4" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4B28F1353 for ; Thu, 4 Aug 2016 04:49:28 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from ::ffff:99.100.19.101 ([99.100.19.101]) by holgerdanske.com for ; Wed, 3 Aug 2016 21:49:26 -0700 Subject: Re: Ominous smartd messages .... To: freebsd-questions@freebsd.org References: <020caa94-b329-d5a6-5bd4-bfcc575c039f@freebsd.org> <4b35b969-606b-9084-5ce3-688eddfc5e70@FreeBSD.org> From: David Christensen X-Enigmail-Draft-Status: N1110 Message-ID: <92733556-2fb1-08dc-ac7a-c54d0247c7ae@holgerdanske.com> Date: Wed, 3 Aug 2016 21:49:26 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Aug 2016 04:49:29 -0000 On 08/03/2016 01:27 PM, William A. Mahaffey III wrote: > Can I do that 'zpool scrub' live ? I try to scrub when the machine is not in use. > No spare SATA slots :-/ .... How about expansion slots -- e.g. PCI, PCIe? > On 08/03/16 15:19, Matthew Seaman wrote: >> Also, the fact that you have how ever many terabytes of data with no >> resilience just makes me feel on edge -- and it's not even my data. +1 >> Strongly recommend rebuilding your zpool as a RAIDZ of 8 drives -- yes, >> you'll end up with less usable space, but you and your data will survive >> failure of a drive and a 'zpool scrub' will be able to fix things even >> if a bad spot on one drive has scrambled some of your data. > > I was/am already thinking along those lines, w/ 1 complication. I have > another box (NetBSD 6.1.5) w/ a RAID5 that I wound up building w/ > mis-aligned disk/RAID blocks in spite of a fair amount of effort to > avoid that. I/O writes are horrible, 15-20 MB/s. My understanding is > that RAIDZn is like RAID5 in many ways & that you always want 2^n+1 > (3,5,9, ...) drives in a RAID5 to mitigate those misalignments, > presumably in a RAIDZ also. Is that so w/ RAIDZ as well ? If so, I lose > more than a small amount of total storage, which is why I went as I did > when I built the box whenever that was. How much data do you have on the 8 @ 1 TB machine? How are you doing backups? Archives? Images? How much data are you willing to lose? What is your usage environment -- e.g. student/ hobbyist, SOHO, SMB, large corporate? What are your budget and schedule? David