From owner-freebsd-questions@FreeBSD.ORG Sat Apr 7 07:34:36 2007 Return-Path: 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 E360C16A403 for ; Sat, 7 Apr 2007 07:34:36 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (ns0.infracaninophile.co.uk [81.187.76.162]) by mx1.freebsd.org (Postfix) with ESMTP id 44ABB13C44C for ; Sat, 7 Apr 2007 07:34:35 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from [IPv6:::1] (localhost.infracaninophile.co.uk [IPv6:::1]) by smtp.infracaninophile.co.uk (8.13.8/8.13.8) with ESMTP id l377YFme016492; Sat, 7 Apr 2007 08:34:15 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) Message-ID: <46174971.9080809@infracaninophile.co.uk> Date: Sat, 07 Apr 2007 08:34:09 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 1.5.0.10 (X11/20070320) MIME-Version: 1.0 To: "R. B. Riddick" References: <219395.34786.qm@web30302.mail.mud.yahoo.com> In-Reply-To: <219395.34786.qm@web30302.mail.mud.yahoo.com> X-Enigmail-Version: 0.94.0.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enigF8D3837A75C93AA178B7C53B" X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (smtp.infracaninophile.co.uk [IPv6:::1]); Sat, 07 Apr 2007 08:34:31 +0100 (BST) X-Virus-Scanned: ClamAV 0.90.1/3031/Sat Apr 7 01:53:25 2007 on happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, DKIM_POLICY_TESTING, DK_POLICY_SIGNSOME,NO_RELAYS autolearn=ham version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on happy-idiot-talk.infracaninophile.co.uk Cc: freebsd-fs@freebsd.org, Mike Wolman , freebsd-questions@freebsd.org Subject: Re: some thoughts about gmirror X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 07 Apr 2007 07:34:37 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF8D3837A75C93AA178B7C53B Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable R. B. Riddick wrote: > Sounds like rsync can already do that (I am not sure right now, if rsyn= c can > find updated areas within a large file, or if it just copies the while = updated > file even if it is a large one)... rsync will find an updated area within a big file. The algorithm is to divide any such file into 100kB[*] chunks, calculate checksums of each of= those chunks and only transfer the chunks where the checksum differs between source and destination. More detail here: http://samba.org/rsync/how-rsync-works.html http://rsync.samba.org/tech_report/tech_report.html Cheers, Matthew [*] For some value of 100kB. --=20 Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW --------------enigF8D3837A75C93AA178B7C53B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.3 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGF0l38Mjk52CukIwRCCxEAJ4q/ZGzMlrQGWh9lfrwSvLmG6h1CgCgk9E/ MdnGSQcZinVp7yibvR3XO+c= =i3/L -----END PGP SIGNATURE----- --------------enigF8D3837A75C93AA178B7C53B--