From owner-freebsd-hackers@FreeBSD.ORG Fri Mar 14 15:27:36 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 D9AA61A8 for ; Fri, 14 Mar 2014 15:27:36 +0000 (UTC) Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com [IPv6:2a00:1450:400c:c05::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 72545920 for ; Fri, 14 Mar 2014 15:27:36 +0000 (UTC) Received: by mail-wi0-f178.google.com with SMTP id n15so2756045wiw.17 for ; Fri, 14 Mar 2014 08:27:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=date:from:to:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; bh=ff40DL2TW6PXu/+h4mVT4BHmnAolTDdi/EyL5qeoWdg=; b=qzKry3NrC0MYF28Wz6uyZG/z1A4lUUyPmrhLoPBCvB0xqyJ4iILei/9GuAq5ZQ2qbR yC0vWRHyNs9FuCEnoo0f8iqeFtW0quhoawJLssbDXaUhu/rauxzOEeWvowNv9FMq7Fs0 KBdFITmSKmkJwcrYGL+1xbpZTA3YPhrvmKw/vgtJuJIKk8MNWuAeH/piOnTE6WwtFssY eVZF9oPvZ/rwrBChm6/U1aFZ5/iY5DeX/5TwgRpvMI6evQXh/yFWki4pwVszzeziGVAP MjGWGW7dJIY5hC4FTT2iW4cVlGA2A/hLOxOGhBGs9X9+YcOJJHtVAgABm3Qszy15oQjr /0hQ== X-Received: by 10.180.165.174 with SMTP id yz14mr6641620wib.34.1394810854948; Fri, 14 Mar 2014 08:27:34 -0700 (PDT) Received: from gumby.homeunix.com (bcdeeb79.skybroadband.com. [188.222.235.121]) by mx.google.com with ESMTPSA id fo6sm17703904wib.7.2014.03.14.08.27.33 for (version=SSLv3 cipher=RC4-SHA bits=128/128); Fri, 14 Mar 2014 08:27:34 -0700 (PDT) Date: Fri, 14 Mar 2014 15:27:32 +0000 From: RW To: freebsd-hackers@freebsd.org Subject: Re: GSoC proposition: multiplatform UFS2 driver Message-ID: <20140314152732.0f6fdb02@gumby.homeunix.com> In-Reply-To: References: X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; amd64-portbld-freebsd10.0) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 15:27:36 -0000 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.