From owner-freebsd-chat@FreeBSD.ORG Wed Apr 21 04:26:03 2004 Return-Path: Delivered-To: freebsd-chat@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F31E316A4CE for ; Wed, 21 Apr 2004 04:26:02 -0700 (PDT) Received: from hutcs.cs.hut.fi (hutcs.cs.hut.fi [130.233.192.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id B8B4943D4C for ; Wed, 21 Apr 2004 04:26:02 -0700 (PDT) (envelope-from kirma@cs.hut.fi) Received: from kirma (helo=localhost) by hutcs.cs.hut.fi with local-esmtp (Exim 4.30) id 1BGFrd-0005OU-Ev; Wed, 21 Apr 2004 14:26:01 +0300 Date: Wed, 21 Apr 2004 14:26:01 +0300 (EEST) From: Jari Kirma To: Brad Knowles In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-chat@freebsd.org Subject: Re: Shadow filesystems [was Re: Pair donates 20,000 to Poul-Henning Kamp??] X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Apr 2004 11:26:03 -0000 On Fri, 16 Apr 2004, Brad Knowles wrote: > After a catastrophic wipeout when I was a student at the > University of Oklahoma about 20 years ago (causing me to work 36 > hours straight to re-create all my hard work), I created a set of > shell script tools to replace the "rm", "mv", "cp", etc... programs > with something that would use a "~/.Trash" directory and then > compress the files, etc.... When I first created these scripts, they > were very popular, and widely used by the student community. IIRC, I > posted a fairly final version of those scripts to comp.sources.*. > ECN staff had a disagreement with me over these tools, thinking > it unwise for people to get used to the "new" behaviour, which might > lead them to get seriously screwed when they used "rm" somewhere else > and it didn't act in the way they expected. However, it wasn't until > after I had another massive wipeout (this time using vi to write a > file into the wrong filename), that I decided that I agreed with them. > So, I removed the scripts from my bin, although others could > always go to the newsgroup archives and pull down their own version > if they wanted. I don't think anyone did. > If you really want to make something like this work, you have to > cover all possible avenues of destruction, not just creat(), > unlink(), and rename routines. Introduce a real filesystem > versioning scheme, and I would gladly welcome your work. As I was actually looking for resources to actually do this, I run to recent paper from FAST 2004 conference: Kiran-Kumar Muniswamy-Reddy, Charles P. Wright, Andrew Himmer, and Erez Zadok: "A Versatile and User-Oriented Versioning File System", . It seems to implement pretty much what is wanted, although sources aren't available, at least yet. It probably uses FiST stackable filesystem toolkit, so it should actually work with Linux, FreeBSD and Solaris if properly implemented. -kirma