From owner-freebsd-questions@FreeBSD.ORG Sat Feb 27 02:30:22 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7EA7F106566B for ; Sat, 27 Feb 2010 02:30:22 +0000 (UTC) (envelope-from cpghost@cordula.ws) Received: from mail-bw0-f216.google.com (mail-bw0-f216.google.com [209.85.218.216]) by mx1.freebsd.org (Postfix) with ESMTP id 1EB5C8FC16 for ; Sat, 27 Feb 2010 02:30:21 +0000 (UTC) Received: by bwz8 with SMTP id 8so568853bwz.3 for ; Fri, 26 Feb 2010 18:30:16 -0800 (PST) MIME-Version: 1.0 Received: by 10.204.15.140 with SMTP id k12mr909705bka.63.1267237815975; Fri, 26 Feb 2010 18:30:15 -0800 (PST) X-Originating-IP: [213.146.115.42] In-Reply-To: References: <478355.21984.qm@web57501.mail.re1.yahoo.com> Date: Sat, 27 Feb 2010 03:30:15 +0100 Message-ID: From: "C. P. Ghost" To: Ffflee Ffflee Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-questions@freebsd.org Subject: Re: about the checksum 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, 27 Feb 2010 02:30:22 -0000 On Fri, Feb 26, 2010 at 11:21 PM, Sean Cavanaugh wrote: > they are there so you can compare the real checksum hash for the .ISO file > against what you downloaded as a way to make sure you downloaded every > single bit of the file or if it has been changed. There are many reasons for checksum files. The main one is -- IMHO -- that people often forget to download the ISO files in BINARY mode, which would clobber the file beyond all recognition. Not so much of a concern nowadays with most downloaders (browers etc...) using binary mode, but it was a big issue back in the FTP days. With a checksum file, you can verify that the ISO is an exact copy of the one you've downloaded. Just run the appropriate checksum command on your end, and compare it to the contents of the checksum file (which, btw, is tiny compared to the ISO!). If both checksums are different, don't use the ISO file, because it was corrupted, and it won't work anyway. -cpghost. -- Cordula's Web. http://www.cordula.ws/