From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from p3plsmtpa07-07.prod.phx3.secureserver.net (p3plsmtpa07-07.prod.phx3.secureserver.net [173.201.192.236]) by sourceware.org (Postfix) with ESMTPS id D8C94385B83E for ; Mon, 31 Jan 2022 15:18:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D8C94385B83E Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kosowsky.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=kosowsky.org Received: from consult.pretender ([146.115.145.129]) by :SMTPAUTH: with ESMTPSA id EYRMnjVZickJLEYRMnkJUn; Mon, 31 Jan 2022 08:18:00 -0700 X-CMAE-Analysis: v=2.4 cv=Hrqzp2fS c=1 sm=1 tr=0 ts=61f7fda8 a=BYuR5sdBHlGgEYWvfiqr5Q==:117 a=BYuR5sdBHlGgEYWvfiqr5Q==:17 a=kj9zAlcOel0A:10 a=DghFqjY3_ZEA:10 a=Y4wjOHm_AAAA:8 a=AW60ofLgYjALZ94YtvIA:9 a=CjuIK1q_8ugA:10 a=vUyUeBe4x1l68iL-zyVZ:22 X-SECURESERVER-ACCT: inbox@kosowsky.org Received: from consult.pretender (localhost [127.0.0.1]) by consult.pretender (Postfix) with ESMTP id 0B021290D935 for ; Mon, 31 Jan 2022 10:18:00 -0500 (EST) Received: by consult.pretender (Postfix, from userid 495) id 075C3290D934; Mon, 31 Jan 2022 10:18:00 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Level: Received: from consult.pretender (localhost [127.0.0.1]) by consult.pretender (Postfix) with ESMTPSA id 1734D290D91A; Mon, 31 Jan 2022 10:17:59 -0500 (EST) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <25079.64935.73349.331715@consult.pretender> Date: Mon, 31 Jan 2022 10:17:59 -0500 To: moss@cs.umass.edu Cc: cygwin@kosowsky.org, cygwin@cygwin.com Subject: Re: Renaming (with 'mv') very large files is SLOW In-Reply-To: References: <25079.63376.349893.86395@consult.pretender> X-Mailer: VM 8.2.0b under 25.2.2 (x86_64-pc-linux-gnu) From: cygwin@kosowsky.org X-Virus-Scanned: ClamAV using ClamSMTP X-CMAE-Envelope: MS4xfGajD0wuX/MXeymOfyplxTMqn+XefyCcmYFbqj8jzZxN+Eaq9ZRXiHdL0AzXbNyR4VDt4Q1N5pJ0y1iWnk4kn/vfK0gGyzEy//54Izwx1GR9TFYGnbOV ZZXvV3anFKKF63ZLcJWCt07Gdt+Z+o0xaLnwx5zPImw7U7eAz9G+39vV/vNiWS/EUTeeGZEmJzw8rS0eA1biAXbLw3ikNJ+yOgU= X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 Jan 2022 15:18:03 -0000 Eliot Moss wrote at about 09:59:17 -0500 on Monday, January 31, 2022: > On 1/31/2022 9:52 AM, cygwin@kosowsky.org wrote: > > I tried renaming some very large files (20-40 GB) using: > > mv > > without changing the directory of course. > > > > The process took about 10-20 minutes with Task Manager showing disk > > activity of 100+ MB/s. > > > > Is there something about such large 'renaming' that actually results > > in the file being really moved (aka copied) rather than just renamed? > > The two places are probably on different volumes (loosely, different disks). > That requires a physical move, even under Linux. No my point is I am just *renaming*, not physically moving the file!! i.e., I am not changing the directory location of the file, let alone the volume/disk location. (I am well aware that 'mv' does a copy when changing volumes/disks). I literally am typing something like: mv foo bar In Linux, that just edits the file system table & inode... UPDATE... I just tried a second 'mv' and it was near instantaneous. (and similarly with subsequent renaming of the same file) So perhaps not a 'Cygwin' thing but something going on within Windows. Could it be that the first 'mv' triggered an anti-virus read of the file since perhaps it detects it as a new/changed file? But if so, would 'mv' (under Task Manager) be showing the 100+ MB/s disk activity?