From owner-freebsd-hackers@FreeBSD.ORG Fri Mar 14 17:57:21 2014 Return-Path: Delivered-To: freebsd-hackers@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 1903710C for ; Fri, 14 Mar 2014 17:57:21 +0000 (UTC) Received: from mho-01-ewr.mailhop.org (mho-03-ewr.mailhop.org [204.13.248.66]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id E1CD0ABD for ; Fri, 14 Mar 2014 17:57:20 +0000 (UTC) Received: from c-24-8-230-52.hsd1.co.comcast.net ([24.8.230.52] helo=damnhippie.dyndns.org) by mho-01-ewr.mailhop.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1WOUCz-0005pY-R1; Fri, 14 Mar 2014 15:39:41 +0000 Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by damnhippie.dyndns.org (8.14.3/8.14.3) with ESMTP id s2EFdcTC064196; Fri, 14 Mar 2014 09:39:38 -0600 (MDT) (envelope-from ian@FreeBSD.org) X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 24.8.230.52 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX19v/MDwyhdbKV/DVd0tFgsp Subject: Re: GSoC proposition: multiplatform UFS2 driver From: Ian Lepore To: RW In-Reply-To: <20140314152732.0f6fdb02@gumby.homeunix.com> References: <20140314152732.0f6fdb02@gumby.homeunix.com> Content-Type: text/plain; charset="us-ascii" Date: Fri, 14 Mar 2014 09:39:37 -0600 Message-ID: <1394811577.1149.543.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@FreeBSD.org 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 17:57:21 -0000 On Fri, 2014-03-14 at 15:27 +0000, RW wrote: > On Thu, 13 Mar 2014 18:22:10 -0800 > Dieter BSD wrote: > > > Julio writes, > > > That being said, I do not like the idea of using NetBSD's UFS2 > > > code. It lacks Soft-Updates, which I consider to make FreeBSD UFS2 > > > second only to ZFS in desirability. > > > > FFS has been in production use for decades. ZFS is still wet behind > > the ears. Older versions of NetBSD have soft updates, and they work > > fine for me. I believe that NetBSD 6.0 is the first release without > > soft updates. They claimed that soft updates was "too difficult" to > > maintain. I find that soft updates are *essential* for data > > integrity (I don't know *why*, I'm not a FFS guru). > > NetBSD didn't simply drop soft-updates, they replaced it with > journalling, which is the approach used by practically all modern > filesystems. > > 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. 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. -- Ian