From owner-freebsd-stable@FreeBSD.ORG Thu Nov 14 15:56:14 2013 Return-Path: Delivered-To: freebsd-stable@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 82CC7CFD; Thu, 14 Nov 2013 15:56:14 +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 EFF712652; Thu, 14 Nov 2013 15:56:13 +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 md50006717722.msg; Thu, 14 Nov 2013 15:56:03 +0000 X-Spam-Processed: mail1.multiplay.co.uk, Thu, 14 Nov 2013 15:56:03 +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=10308a6844=killing@multiplay.co.uk X-Envelope-From: killing@multiplay.co.uk Message-ID: From: "Steven Hartland" To: "Andriy Gapon" , , References: <20967.760.95825.310085@gargle.gargle.HOWL><51E80B30.1090004@FreeBSD.org><20968.10645.880772.30501@gargle.gargle.HOWL><520202E5.30300@FreeBSD.org><20994.55913.93606.436124@gargle.gargle.HOWL> <21111.12085.958991.356982@gargle.gargle.HOWL> <4EB902F80CE84DD2BF36C85EF4CE8EF8@multiplay.co.uk> <5284B8A5.8040604@FreeBSD.org> Subject: Re: Help with filing a [maybe] ZFS/mmap bug. Date: Thu, 14 Nov 2013 15:55:57 -0000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original 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 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.16 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, 14 Nov 2013 15:56:14 -0000 ----- Original Message ----- From: "Andriy Gapon" >>> I was able recreate the problem on a 10-BETA-something-or-other >>> recently (I'd only been using 9 up until then). Andriy's patches >>> didn't make a difference. I haven't heard anything since reporting >>> back to him. >> >> I've pretty much confirmed mmap support is causing the corruption when >> running rrdcached as since rebuilding with mmap disabled I've had no >> further corruption. > > Well, this is not a _proof_, of course... Proof that mmap is causing the corruption, not that ZFS mmap support is the point at fault, as the code in rrdtool takes a different path so could still be an application error, but without mmap enabled I've seen zero corruption so... >> @George when you got corruption what did the files look like? I ask as >> here I see lots of zeros as through the file size was correct but pretty >> much blanked. > > Steve, could you please provide a little bit more of description of the > corruption that you got. Lengths of those zeroed regions, their offsets (modulo > page size). > Anything that could establish a pattern (if any exists). They all seem to be corrupted to the same file which when dumped using hexdump -C results in: 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00001000 00 00 00 00 00 00 f8 ff 00 00 00 00 00 00 f8 ff |................| * 000a8000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000af000 00 00 00 00 00 00 f8 ff 00 00 00 00 00 00 f8 ff |................| * 00113de0 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.