From owner-freebsd-stable@FreeBSD.ORG Tue Jul 1 19:23:51 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8DA32AD8 for ; Tue, 1 Jul 2014 19:23:51 +0000 (UTC) Received: from mail-we0-x236.google.com (mail-we0-x236.google.com [IPv6:2a00:1450:400c:c03::236]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1E75F25E1 for ; Tue, 1 Jul 2014 19:23:50 +0000 (UTC) Received: by mail-we0-f182.google.com with SMTP id q59so10221035wes.27 for ; Tue, 01 Jul 2014 12:23:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:mail-followup-to :references:mime-version:content-type:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=byuLybheZ9n6ElCH8NxiU8RUB4otpVQAYR8PwGj72sY=; b=ImOAzYKlGyEfiyvZWbaodVw/ZgYKbewixiaJeCNapa0zWOA6SzWk20rcOmbvgj2pbF Q9MCfb0DW5x5gSUazVYoccKNlJEMFwK2dZ+21e/xljQtrjKkwUzvZgSzeyODfyjRZsUV 9DFc6K4/TXvDedmJ0GTY5dVVSysV9quZIXD2prWKulLUdA2B28729IVyPmRjeG1hfBJT JZP+bDLEfsWjgen7NZKX0KyhHcm4gZqGjcgFfm5b4dH+2381sPJ2i3i7xqsLvpervabL r0g1XhghtVxmeNCxxGdTwG+k9r4yrg5XqO0m9lmtlSej0HCpKHSxpYR9qBafHNLMiN8D zvEg== X-Received: by 10.194.243.104 with SMTP id wx8mr53640286wjc.32.1404242629269; Tue, 01 Jul 2014 12:23:49 -0700 (PDT) Received: from brick.home (adfl225.neoplus.adsl.tpnet.pl. [79.184.115.225]) by mx.google.com with ESMTPSA id di7sm49969079wjb.34.2014.07.01.12.23.48 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Jul 2014 12:23:48 -0700 (PDT) Sender: =?UTF-8?Q?Edward_Tomasz_Napiera=C5=82a?= Date: Tue, 1 Jul 2014 21:23:46 +0200 From: Edward Tomasz =?utf-8?Q?Napiera=C5=82a?= To: Dmitry Sivachenko Subject: Re: 10/stable panic: softdep_deallocate_dependencies: dangling deps Message-ID: <20140701192346.GA9551@brick.home> Mail-Followup-To: Dmitry Sivachenko , Ronald Klop , freebsd-stable@freebsd.org References: <021AFCAD-7B0B-47FB-AAFF-8F7085C7E1A6@gmail.com> <20140701184749.GA8617@brick.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Cc: freebsd-stable@freebsd.org, Ronald Klop X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Jul 2014 19:23:51 -0000 On 0701T2317, Dmitry Sivachenko wrote: > > On 01 июля 2014 г., at 22:47, Edward Tomasz Napierała wrote: > > > > Soft updates cannot gracefully handle IO errors. It _will_ panic. > > You can either prevent errors from happening by using redundancy > > (ie. mirroring), or disable soft updates. That's how it works, > > sorry. > > > > In theory it would be possible to prevent this from happening; > > panic here is actually to terminate the system before it corrupts > > data, and in situations like this one, where the disk is no longer > > accessible, it's not possible to corrupt anything. IIRC I've > > actually added a workaround for that a while ago, but, as you can > > see, it's not enough, and I don't understand soft updates well > > enough to fix it properly. > > > > > Will ZFS fail without a panic? Or UFS without SU is the only choice? I believe ZFS will behave properly. One thing to note is the "failmode" zpool (not zfs) property. By default, it's set to "wait", which means access to data stored on a faulty disk (with no redundancy) will be blocked (paused, hanging) instead of returning IO error.