From owner-freebsd-questions@FreeBSD.ORG Thu Mar 13 17:47:18 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 30C1FC96 for ; Thu, 13 Mar 2014 17:47:18 +0000 (UTC) Received: from email2.allantgroup.com (email2.emsphone.com [199.67.51.116]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id CEFC3932 for ; Thu, 13 Mar 2014 17:47:17 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [172.17.17.101]) by email2.allantgroup.com (8.14.7/8.14.7) with ESMTP id s2DHkOp4093929 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 13 Mar 2014 12:46:24 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.7/8.14.6) with ESMTP id s2DHkOj1021323 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 13 Mar 2014 12:46:24 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.8/8.14.7/Submit) id s2DHkNZm021322; Thu, 13 Mar 2014 12:46:23 -0500 (CDT) (envelope-from dan) Date: Thu, 13 Mar 2014 12:46:23 -0500 From: Dan Nelson To: "Christopher J. Ruwe" Subject: Re: cannot witness rsync delta-algorithm Message-ID: <20140313174623.GA98098@dan.emsphone.com> References: <20140313175526.1ea13c4f@dijkstra-old.hb22.cruwe.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140313175526.1ea13c4f@dijkstra-old.hb22.cruwe.de> X-OS: FreeBSD 9.2-STABLE User-Agent: Mutt/1.5.22 (2013-10-16) X-Virus-Scanned: clamav-milter 0.98.1 at email2.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (email2.allantgroup.com [172.17.19.78]); Thu, 13 Mar 2014 12:46:24 -0500 (CDT) X-Spam-Status: No, score=-3.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, T_RP_MATCHES_RCVD,URIBL_BLOCKED autolearn=ham version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on email2.allantgroup.com X-Scanned-By: MIMEDefang 2.73 Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Mar 2014 17:47:18 -0000 In the last episode (Mar 13), Christopher J. Ruwe said: > From what I understand from rsync workings, I would expect another > rsync from 'here' to 'there' only to copy some MBs due to possibly > different window sizes, but significantly less than 100MB. Yet, it > does not. Why? > > [cjr@dijkstra:~/rsync-exp]$ rsync -vhc --inplace here there > sent 104.88M bytes received 35 bytes 69.92M bytes/sec > total size is 104.86M speedup is 1.00 > > 'here' has been copied as a whole to 'there'. The '-W' flag has not > been set! Yes it has :) From the manpage: -W, --whole-file With this option rsync's delta-transfer algorithm is not used and the whole file is sent as-is instead. The transfer may be faster if this option is used when the bandwidth between the source and destination machines is higher than the bandwidth to disk (especially when the "disk" is actually a networked filesystem). This is the default when both the source and destination are specified as local paths, but only if no batch-writing option is in effect. Since the delta algorithm has to read both files and checksum them, rsync assumes that a plain copy will be more efficient for local files. What happens if you add --no-whole-file to your commandline? -- Dan Nelson dnelson@allantgroup.com