From owner-freebsd-questions@FreeBSD.ORG  Thu Apr 26 06:35:37 2007
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
X-Original-To: freebsd-questions@freebsd.org
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id DFB1D16A407
	for <freebsd-questions@freebsd.org>;
	Thu, 26 Apr 2007 06:35:37 +0000 (UTC) (envelope-from on@cs.ait.ac.th)
Received: from mail.cs.ait.ac.th (mail.cs.ait.ac.th [192.41.170.16])
	by mx1.freebsd.org (Postfix) with ESMTP id 607AC13C45E
	for <freebsd-questions@freebsd.org>;
	Thu, 26 Apr 2007 06:35:37 +0000 (UTC) (envelope-from on@cs.ait.ac.th)
Received: from banyan.cs.ait.ac.th (banyan.cs.ait.ac.th [192.41.170.5])
	by mail.cs.ait.ac.th (8.13.1/8.12.11) with ESMTP id l3Q6ZZUs066710
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO);
	Thu, 26 Apr 2007 13:35:35 +0700 (ICT)
Received: (from on@localhost)
	by banyan.cs.ait.ac.th (8.13.3/8.12.11) id l3Q6ZZhL090019;
	Thu, 26 Apr 2007 13:35:35 +0700 (ICT)
Date: Thu, 26 Apr 2007 13:35:35 +0700 (ICT)
Message-Id: <200704260635.l3Q6ZZhL090019@banyan.cs.ait.ac.th>
From: Olivier Nicole <on@cs.ait.ac.th>
To: m.seaman@infracaninophile.co.uk
In-reply-to: <463044C1.6080107@infracaninophile.co.uk> (message from Matthew
	Seaman on Thu, 26 Apr 2007 07:20:49 +0100)
References: <06D1B6D4926222458F803D0D3EDCCB7E01D0A4AC@EXM1.otc.edu>
	<463044C1.6080107@infracaninophile.co.uk>
X-Virus-Scanned: on CSIM by amavisd-milter (http://www.amavis.org/)
Cc: garrisot@otc.edu, freebsd-questions@freebsd.org
Subject: Re: Single Instance Service
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 26 Apr 2007 06:35:38 -0000

> Sure it is.  You will need to write a small shell script to scan
> your disk volume and calculate the checksum of each file.  When
> ever it finds a duplicated checksum, then it copies the file into
> the central store and replaces the on-disk copies with symbolic
> links.  That's fairly trivial to write.

Beside, what should be the behaviour when one wishes to modify his own
copy of a document? How does Single Instance acts in that case?

If you establish a link, there is only one version of the file, once
and forever (unless you go and unlink it manually), so when one
modifies the file, modification applies for everyone.

Olivier