From owner-freebsd-questions@FreeBSD.ORG Fri Oct 21 16:08:31 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3024216A41F for ; Fri, 21 Oct 2005 16:08:31 +0000 (GMT) (envelope-from freebsd-questions-local@be-well.ilk.org) Received: from mail23.sea5.speakeasy.net (mail23.sea5.speakeasy.net [69.17.117.25]) by mx1.FreeBSD.org (Postfix) with ESMTP id D967143D46 for ; Fri, 21 Oct 2005 16:08:29 +0000 (GMT) (envelope-from freebsd-questions-local@be-well.ilk.org) Received: (qmail 23661 invoked from network); 21 Oct 2005 16:08:25 -0000 Received: from dsl092-078-145.bos1.dsl.speakeasy.net (HELO be-well.ilk.org) ([66.92.78.145]) (envelope-sender ) by mail23.sea5.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 21 Oct 2005 16:08:25 -0000 Received: by be-well.ilk.org (Postfix, from userid 1147) id 7E02934; Fri, 21 Oct 2005 12:08:24 -0400 (EDT) Sender: lowell@be-well.ilk.org To: user References: From: Lowell Gilbert Date: 21 Oct 2005 12:08:24 -0400 In-Reply-To: Message-ID: <4464rq3laf.fsf@be-well.ilk.org> Lines: 29 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-questions@freebsd.org Subject: Re: FreeBSD UFS2 snapshots, and math ... - resolved, but two more Qs X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-questions@freebsd.org List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Oct 2005 16:08:31 -0000 user writes: > On 21 Oct 2005, Lowell Gilbert wrote: > > > The snapshot doesn't know what the bits in the file are. All it knows > > is that the file's data used to be, say in "block 1857" and now the > > file's data are in "block 1956". The fact that both blocks are > > identical is not detected. > > > > If you're really interested in this, I suggest reading a decent > > operating systems book. It's a lot easier to understand the specific > > implementation when you have a good grip on the standard terminology > > and principles. > > > Thanks very much for your help. I am going to read a book or two - my > plan was to start with "the design adn implementation of the 4.4BSD OS", > but I wanted to update it with more modern information - like snapshots, > etc., which I will do with those URLs we have already posted RE: the > snapshot work. > > If you have any others, let me know. Yes. Start with something more basic, because McKusick's books assume that you are already acquainted with the standard terminology. Tanenbaum's are the usual recommendations. And when you do get to McKusick, you'll do a lot better with the new "Design and Implementation of the FreeBSD Operating System," which covers a lot of these recent improvements.