From owner-freebsd-hackers@FreeBSD.ORG Tue Jun 9 17:36:34 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E0053106570F; Tue, 9 Jun 2009 17:36:34 +0000 (UTC) (envelope-from dan.naumov@gmail.com) Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.246]) by mx1.freebsd.org (Postfix) with ESMTP id 6CDE68FC16; Tue, 9 Jun 2009 17:36:34 +0000 (UTC) (envelope-from dan.naumov@gmail.com) Received: by an-out-0708.google.com with SMTP id c3so65755ana.13 for ; Tue, 09 Jun 2009 10:36:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=5SyXc+qjJNnTJflKIZcpdZprMJz4xT9fVcwPgSnQB7E=; b=ahNknRepa+0JlCKQT+RTfn/FVYUkxtXCSKRQP8mNlTEpCkY6NUWCdwlFiAp5j9KWof CtLuA6USBG896TfzsCSyFBQHSGdLO4hz0zZ87TfZEZPiAM/Qe5gKU3C9p1cOl9+LzJpH 9Y01qTDmbyjDX8qI5qzvPHz903YuwJwIjNuR8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=WS2wRHuqwjzn8PfMybA3V+zzXb78WbNO/9mBODVnpdGErXeXLE0nEhhH6oJmHm0R6W 0H4sDJu0M288HbzAO3d464l92b51EjkEFnw1ka1PcvIBHaTq8p5gQEG/s2p1zlEMcWiy C9w3DgprTzLq0ZifOrO3lwcxo9l5kiYgkAabI= MIME-Version: 1.0 Received: by 10.100.108.2 with SMTP id g2mr347157anc.35.1244568993797; Tue, 09 Jun 2009 10:36:33 -0700 (PDT) In-Reply-To: <20090609172142.GA92146@ebi.local> References: <20090609172142.GA92146@ebi.local> Date: Tue, 9 Jun 2009 20:36:33 +0300 Message-ID: From: Dan Naumov To: Nick Barkas Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Tue, 09 Jun 2009 18:03:37 +0000 Cc: freebsd-hackers@freebsd.org, freebsd-current@freebsd.org Subject: Re: sysinstall, GJOURNAL and ZFS X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Jun 2009 17:36:35 -0000 I know some might dismiss my personal experience as "anecdotal", but yes I have had that happen to me twice. Some googling will show that I am not the only one to ever experience fatal UFS+softupdates failures. I even ran into a page from 2006 (I think), where a fellow wrote some code which would write data to an UFS2 partition that would consistently cause fsck to fail. This actually brings up to another related point, having to actually deal with fsck. On filesystems/volumes of today, which can easily span 10tb+ in a production environment, having to deal with fsck times is a complete no-go. One could of course argue that environments where 10tb+ volumes are used right now are special cases, where the administrator would know of these issues and take appropriate measures to deal with it (UPS, custom installation with gjournal, ZFS, etc), my point still stands. Right now, anyone can walk into a computer store and purchase a consumer 1,5tb or 2tb drive. Have you tried running fsck on a 2tb filesystem? It's not fun. And this will only get worse with time as drive sizes continue to grow. - Dan Naumov On Tue, Jun 9, 2009 at 8:21 PM, Nick Barkas wrote: > Can you back this up? I cannot recall having ever rendered a FreeBSD > system unbootable due to UFS/UFS2 problems after a power failure or > crash. I once had a problem with snapshots that made background fsck > fail and crash the system, but it was fixable by booting single user and > running fsck manually. This was a couple of years ago, and I think the > problem has since been fixed. > > ZFS at least probably is not able to replace UFS2 for everyone, at this > time, anyway. Perhaps gjournal can be a replacement for softupdates for > many people who do still need UFS2, but I'm not sure. I think in any > case, any existing bugs that cause UFS2+softupdates to catastrophically > fail in the event of power failures or system crashes need to be fixed. > Making it easier for users to install a system with ZFS or gjournal does > nothing for those who have existing systems with UFS2+softupdates, and > those who cannot use ZFS or gjournal in the near future for whatever > reason. > > That being said, I do agree that being able to support ZFS and gjournal > in sysinstall or an alternative installer would be great. > > Nick >