From owner-freebsd-fs@FreeBSD.ORG Fri Jan 10 13:24:55 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id D54CF9B8 for ; Fri, 10 Jan 2014 13:24:55 +0000 (UTC) Received: from mail1.multiplay.co.uk (mail1.multiplay.co.uk [85.236.96.23]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 708BC1B55 for ; Fri, 10 Jan 2014 13:24:55 +0000 (UTC) Received: from r2d2 ([82.69.141.170]) by mail1.multiplay.co.uk (mail1.multiplay.co.uk [85.236.96.23]) (MDaemon PRO v10.0.4) with ESMTP id md50007504535.msg for ; Fri, 10 Jan 2014 13:24:46 +0000 X-Spam-Processed: mail1.multiplay.co.uk, Fri, 10 Jan 2014 13:24:46 +0000 (not processed: message from valid local sender) X-MDDKIM-Result: neutral (mail1.multiplay.co.uk) X-MDRemoteIP: 82.69.141.170 X-Return-Path: prvs=1087d2331c=killing@multiplay.co.uk X-Envelope-From: killing@multiplay.co.uk X-MDaemon-Deliver-To: freebsd-fs@freebsd.org Message-ID: <29BFE2939CF14317A149D6C2D68D9A8E@multiplay.co.uk> From: "Steven Hartland" To: "Attila Nagy" , "Dmitry Morozovsky" References: <52CFA0B6.7090109@fsn.hu> <52CFF18F.5040809@fsn.hu> Subject: Re: What does ZFS write when nothing should write there? Date: Fri, 10 Jan 2014 13:24:25 -0000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: 'freebsd-fs' X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Jan 2014 13:24:55 -0000 ----- Original Message ----- From: "Attila Nagy" > On 01/10/14 14:08, Dmitry Morozovsky wrote: >> On Fri, 10 Jan 2014, Attila Nagy wrote: >> >>> I've created 6 zpools, each of them with zpool create -m /data/A dataA mirror >>> daX daY. >>> The machine has nothing running except sshd and my shell. >>> >>> Yet, I see this in gstat: >> [snip] >> >>> 0 88 0 0 0.0 82 573 4.1 9.0 da5 >>> 0 89 0 0 0.0 83 573 4.8 9.8 da6 >>> 0 87 0 0 0.0 81 573 2.6 5.7 da9 >>> 0 89 0 0 0.0 84 573 3.0 6.7 da10 >> Did you turn off atime? >> > No, but how does it matter? > The process list is the following: init, getty, sshd, csh and the pool > is completely empty. With atime on each time you access a file it will update its "atime" hence causing writes. We use atime=off at the pool level on all machines to avoid that zfs set atime=off Regards Steve ================================================ This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337 or return the E.mail to postmaster@multiplay.co.uk.