From owner-freebsd-hackers@FreeBSD.ORG Fri Mar 14 18:17:41 2014 Return-Path: Delivered-To: freebsd-hackers@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 A1ECC65B; Fri, 14 Mar 2014 18:17:41 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 828A7CA2; Fri, 14 Mar 2014 18:17:41 +0000 (UTC) Received: from [192.168.1.157] (pool-173-52-87-124.nycmny.fios.verizon.net [173.52.87.124]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: ryao) by smtp.gentoo.org (Postfix) with ESMTPSA id 7EAB233F141; Fri, 14 Mar 2014 18:17:40 +0000 (UTC) References: <20140314152732.0f6fdb02@gumby.homeunix.com> <1394811577.1149.543.camel@revolution.hippie.lan> Mime-Version: 1.0 (1.0) In-Reply-To: <1394811577.1149.543.camel@revolution.hippie.lan> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message-Id: <1626A8BF-3875-4287-9F85-51F387986736@gentoo.org> X-Mailer: iPad Mail (10B146) From: Richard Yao Subject: Re: GSoC proposition: multiplatform UFS2 driver Date: Fri, 14 Mar 2014 14:17:38 -0400 To: Ian Lepore Cc: "freebsd-hackers@FreeBSD.org" , RW X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 14 Mar 2014 18:17:41 -0000 On Mar 14, 2014, at 11:39 AM, Ian Lepore wrote: > On Fri, 2014-03-14 at 15:27 +0000, RW wrote: >> A number of people on the questions list have said that they find >> UFS+SU to be considerably less robust than the journalled filesystems >> of other OS's. =20 >=20 > What I've seen claimed is that UFS+SUJ is less robust. That's a very > different thing than UFS+SU. Journaling was nailed onto the side of UFS > +SU as an afterthought, and it shows. This makes sense to me and I am more willing to believe it than the previous= claim. I have yet to see a report of a problem involving soft updates that c= ould not have been caused by hardware doing something UFS2 SU was not design= ed to handle, such as a misdirected write. Sadly, such reports lack the deta= il needed to distinguish between filesystem bugs and hardware errors. Placin= g UFS2 SU on a ZFS zvol would prevent such failure modes from happening.=