From owner-freebsd-hackers@FreeBSD.ORG Wed Aug 2 17:46:26 2006 Return-Path: X-Original-To: freebsd-hackers@FreeBSD.ORG Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EEA8D16A4DE for ; Wed, 2 Aug 2006 17:46:26 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [83.120.8.8]) by mx1.FreeBSD.org (Postfix) with ESMTP id 24EA143D53 for ; Wed, 2 Aug 2006 17:46:25 +0000 (GMT) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (wxklmr@localhost [127.0.0.1]) by lurza.secnetix.de (8.13.4/8.13.4) with ESMTP id k72HkIAU004012 for ; Wed, 2 Aug 2006 19:46:24 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.13.4/8.13.1/Submit) id k72HkIRO004011; Wed, 2 Aug 2006 19:46:18 +0200 (CEST) (envelope-from olli) Date: Wed, 2 Aug 2006 19:46:18 +0200 (CEST) Message-Id: <200608021746.k72HkIRO004011@lurza.secnetix.de> From: Oliver Fromme To: freebsd-hackers@FreeBSD.ORG In-Reply-To: <20060802145422.11A9C2948D@mail.bitblocks.com> X-Newsgroups: list.freebsd-hackers User-Agent: tin/1.8.0-20051224 ("Ronay") (UNIX) (FreeBSD/4.11-STABLE (i386)) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Wed, 02 Aug 2006 19:46:24 +0200 (CEST) X-Mailman-Approved-At: Wed, 02 Aug 2006 20:40:27 +0000 Cc: Subject: Re: [PATCH] adding two new options to 'cp' X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-hackers@FreeBSD.ORG List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Aug 2006 17:46:27 -0000 Bakul Shah wrote: > Peter Jeremy wrote: > > As a general comment (not addressed to Tim): There _is_ a downside > > to sparsifying files. If you take a sparse file and start filling > > in the holes, the net result will be very badly fragmented and hence > > have very poor sequential I/O performance. If you're never going to > > update a file then making it sparse makes sense, if you will be > > updating it, you will get better performance by making it non-sparse. > > Except for database tables how common is this? For example image files of media, e.g. ISO9660 images or images of hard disk partitions. I often have to handle such images, and I certainly do _not_ want them to be sparse. Before someone adds a bogus "sparse file support" option to cp(1), I would rather prefer that someone fixes the existing -R option which currently doesn't handle hard- links correctly. That flaw is documented in the manual page, so it might not count as a "bug", but it's a flaw nevertheless. A lot of people -- even so-called professional admins -- use "cp -Rp" to copy directory hierarchies, and afterwards they wonder why the copy takes up much more space than the original, because all hardlinks have been copied as separate files (if they notice at all). Oh by the way: Linux' option for sparse file handling is "--sparse", and there is no one-letter option (both -s and -S exist, but have nothing to do with sparse files). So there wouldn't be an easy way for FreeBSD to stay compatible with Linux. Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd Any opinions expressed in this message may be personal to the author and may not necessarily reflect the opinions of secnetix in any way. "I have stopped reading Stephen King novels. Now I just read C code instead." -- Richard A. O'Keefe