From owner-freebsd-stable@FreeBSD.ORG Thu Jan 20 02:40:18 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8B7C3106566C for ; Thu, 20 Jan 2011 02:40:18 +0000 (UTC) (envelope-from dan@langille.org) Received: from nyi.unixathome.org (nyi.unixathome.org [64.147.113.42]) by mx1.freebsd.org (Postfix) with ESMTP id 5B36F8FC2B for ; Thu, 20 Jan 2011 02:40:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by nyi.unixathome.org (Postfix) with ESMTP id 14B0E50C18; Thu, 20 Jan 2011 02:40:17 +0000 (GMT) X-Virus-Scanned: amavisd-new at unixathome.org Received: from nyi.unixathome.org ([127.0.0.1]) by localhost (nyi.unixathome.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OB3PhbPG1Mfi; Thu, 20 Jan 2011 02:40:16 +0000 (GMT) Received: from smtp-auth.unixathome.org (smtp-auth.unixathome.org [10.4.7.7]) (Authenticated sender: hidden) by nyi.unixathome.org (Postfix) with ESMTPSA id 6A51C50852 ; Thu, 20 Jan 2011 02:40:16 +0000 (GMT) Message-ID: <4D37A094.1090504@langille.org> Date: Wed, 19 Jan 2011 21:40:20 -0500 From: Dan Langille Organization: The FreeBSD Diary User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: John Hawkes-Reed References: <4D228F41.7040403@langille.org> <4D23504D.8060103@libeljournal.com> <4D2BD0A7.9060003@langille.org> <4D2C810E.2070007@libeljournal.com> In-Reply-To: <4D2C810E.2070007@libeljournal.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable Subject: Re: ZFS - hot spares : automatic or not? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Jan 2011 02:40:18 -0000 On 1/11/2011 11:10 AM, John Hawkes-Reed wrote: > On 11/01/2011 03:38, Dan Langille wrote: >> On 1/4/2011 11:52 AM, John Hawkes-Reed wrote: >>> On 04/01/2011 03:08, Dan Langille wrote: >>>> Hello folks, >>>> >>>> I'm trying to discover if ZFS under FreeBSD will automatically pull >>>> in a >>>> hot spare if one is required. >>>> >>>> This raised the issue back in March 2010, and refers to a PR opened in >>>> May 2009 >>>> >>>> * http://lists.freebsd.org/pipermail/freebsd-fs/2010-March/007943.html >>>> * http://www.freebsd.org/cgi/query-pr.cgi?pr=134491 >>>> >>>> In turn, the PR refers to this March 2010 post referring to using devd >>>> to accomplish this task. >>>> >>>> http://lists.freebsd.org/pipermail/freebsd-stable/2010-March/055686.html >>>> >>>> >>>> Does the above represent the the current state? >>>> >>>> I ask because I just ordered two more HDD to use as spares. Whether >>>> they >>>> sit on the shelf or in the box is open to discussion. >>> >>> As far as our testing could discover, it's not automatic. >>> >>> I wrote some Ugly Perl that's called by devd when it spots a drive-fail >>> event, which seemed to DTRT when simulating a failure by pulling a >>> drive. >> >> Without such a script, what is the value in creating hot spares? > > We went through that loop in the office. > > We're used to the way the Netapps work here, where often one's first > notice of a failed disk is a visit from the courier with a replacement. > (I'm only half joking) > > In the end, writing enough perl to swap in the spare disk made much more > sense than paging the relevant admin on disk-fail and expecting them to > be able to type straight at 4AM. > > Our thinking is that having a hot spare allows us to do the physical > disk-swap in office hours, rather than (for instance) running in a > degraded state over a long weekend. > > If it's of interest, I'll see if I can share the code. I think this very much of interest. :) -- Dan Langille - http://langille.org/