From owner-freebsd-hackers@FreeBSD.ORG Thu Mar 10 02:36:33 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 879A516A4CE; Thu, 10 Mar 2005 02:36:33 +0000 (GMT) Received: from VARK.MIT.EDU (VARK.MIT.EDU [18.95.3.179]) by mx1.FreeBSD.org (Postfix) with ESMTP id C5EFF43D2F; Thu, 10 Mar 2005 02:36:32 +0000 (GMT) (envelope-from das@FreeBSD.ORG) Received: from VARK.MIT.EDU (localhost [127.0.0.1]) by VARK.MIT.EDU (8.13.3/8.13.1) with ESMTP id j2A2ZJRM011821; Wed, 9 Mar 2005 21:35:19 -0500 (EST) (envelope-from das@FreeBSD.ORG) Received: (from das@localhost) by VARK.MIT.EDU (8.13.3/8.13.1/Submit) id j2A2ZJWi011820; Wed, 9 Mar 2005 21:35:19 -0500 (EST) (envelope-from das@FreeBSD.ORG) Date: Wed, 9 Mar 2005 21:35:19 -0500 From: David Schultz To: Mikhail Teterin Message-ID: <20050310023518.GA11712@VARK.MIT.EDU> Mail-Followup-To: Mikhail Teterin , hackers@FreeBSD.ORG, freebsd-fs@FreeBSD.ORG References: <200503091838.06322.mi+mx@aldan.algebra.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200503091838.06322.mi+mx@aldan.algebra.com> cc: freebsd-fs@FreeBSD.ORG cc: hackers@FreeBSD.ORG Subject: Re: the current status of nullfs, unionfs X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Mar 2005 02:36:33 -0000 On Wed, Mar 09, 2005, Mikhail Teterin wrote: > Hello! > > The respected manual contain dire warnings, but the Google search suggests, > the situation is not *that* gloomy. > > For example, according to http://kerneltrap.org/node/652 , nullfs was used on > Bento-cluster two years ago in 2003. > > Is anybody working on this file-systems? Any plans, rumours? Nullfs works better than unionfs. Unionfs worked well in 4.X. Despite numerous minor bugs such as being unable to cope with FIFOs, several people have reported using it quite successfully on production systems. However, unionfs no longer works quite as well in 5.X or -CURRENT. There are several reasons for this: 1. Nobody seems to have both the time and interest to maintain it. 2. Developers can't be expected to prevent regressions in something that's unsupported. 3. There are a couple of people who always respond to questions about unionfs with comments along the lines of: ``It's broken, so we won't help you. Go away and don't tell us if you find any bugs.'' There's some pretty low-hanging fruit in terms of nits to fix. See the PR database if you're interested in helping, and don't let anyone scare you away. ;-) > What about the `union' option to regular mounts? Is that safe to use? Last I checked, it was very broken, but I'm not sure.