From owner-freebsd-stable@FreeBSD.ORG Wed Feb 17 08:57:10 2010 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 753331065679 for ; Wed, 17 Feb 2010 08:57:10 +0000 (UTC) (envelope-from bartosz.stec@it4pro.pl) Received: from mainframe.kkip.pl (kkip.pl [87.105.164.78]) by mx1.freebsd.org (Postfix) with ESMTP id DE67D8FC14 for ; Wed, 17 Feb 2010 08:57:09 +0000 (UTC) Received: from static-78-8-144-74.ssp.dialog.net.pl ([78.8.144.74] helo=[192.168.0.2]) by mainframe.kkip.pl with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.71 (FreeBSD)) (envelope-from ) id 1NhfiP-0001m2-Ou for freebsd-stable@freebsd.org; Wed, 17 Feb 2010 09:57:08 +0100 Message-ID: <4B7BAF59.7040407@it4pro.pl> Date: Wed, 17 Feb 2010 09:56:57 +0100 From: Bartosz Stec Organization: IT4Pro User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) Gecko/20100125 Shredder/3.0.1 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <20100215090756.GA54764@icarus.home.lan> <20100215105000.101326yj01j0f64g@webmail.leidinger.net> <20100215122744.GA57382@icarus.home.lan> <20100215161105.14071eiflhc9le68@webmail.leidinger.net> <4B79BA9C.3020402@quip.cz> <4B7AD0A3.9080701@barryp.org> <20100216175946.GA98082@icarus.home.lan> <20100216200511.GA95812@server.vk2pj.dyndns.org> <20100216215637.GA4299@icarus.home.lan> <4B7BA6A5.9020306@it4pro.pl> <20100217093237.fe4b4e14.torfinn.ingolfsen@broadpark.no> In-Reply-To: <20100217093237.fe4b4e14.torfinn.ingolfsen@broadpark.no> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-User: bartosz.stec@it4pro.pl X-Authenticator: plain X-Sender-Verify: SUCCEEDED (sender exists & accepts mail) X-Spam-Score: -8.2 X-Spam-Score-Int: -81 X-Exim-Version: 4.71 (build at 02-Feb-2010 20:10:28) X-Date: 2010-02-17 09:57:08 X-Connected-IP: 78.8.144.74:63200 X-Message-Linecount: 45 X-Body-Linecount: 32 X-Message-Size: 2221 X-Body-Size: 1039 X-Received-Count: 1 X-Recipient-Count: 1 X-Local-Recipient-Count: 1 X-Local-Recipient-Defer-Count: 0 X-Local-Recipient-Fail-Count: 0 Subject: Re: ZFS tuning [was: hardware for home use large storage] 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: Wed, 17 Feb 2010 08:57:10 -0000 On 2010-02-17 09:32, Torfinn Ingolfsen wrote: > On Wed, 17 Feb 2010 09:19:49 +0100 > Bartosz Stec wrote: > > >> So here's my reply (last line seems most interesting ;) : >> > [...snipped...] > >> Illegal division by zero at ./arc_summary.pl line 242. >> > FWIW, I also got this line when I ran this script on my idle zfs server. > I'm not a PERL programmer (or programmer at all ;), but what I see is script doesn't check if L2ARC is used at all, so it will always try compute these lines: printf("\tL2 Hit Ratio:\t\t\t%0.2f%%\t%d\n", 100 * ( $l2_hits / ( $l2_hits + $l2_misses )), $l2_hits ); printf("\tL2 Miss Ratio:\t\t\t%0.2f%%\t%d\n", 100 * ( $l2_misses / ( $l2_hits + $l2_misses )), $l2_misses ); printf("\tL2 Feeds Ratio:\t\t\t%0.2f%%\t%d\n", 100 * ( $l2_feeds / ( $l2_hits + $l2_misses )), $l2_feeds ); Without active L2ARC it will always generate divide at zeo error, so it seems that additional check for usable L2ARC values is needed at first place. -- Bartosz Stec