From owner-freebsd-questions@FreeBSD.ORG Fri Mar 2 01:06:31 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 2103916A401 for ; Fri, 2 Mar 2007 01:06:31 +0000 (UTC) (envelope-from jekillen@prodigy.net) Received: from smtp113.sbc.mail.mud.yahoo.com (smtp113.sbc.mail.mud.yahoo.com [68.142.198.212]) by mx1.freebsd.org (Postfix) with SMTP id D423313C441 for ; Fri, 2 Mar 2007 01:06:30 +0000 (UTC) (envelope-from jekillen@prodigy.net) Received: (qmail 68833 invoked from network); 2 Mar 2007 01:06:30 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=prodigy.net; h=Received:X-YMail-OSG:In-Reply-To:References:Mime-Version:Content-Type:Message-Id:Content-Transfer-Encoding:Cc:From:Subject:Date:To:X-Mailer; b=6P49nlKMT2SINqMFfDob8I9rB0qF6KekBqj+VGEzf0+Q5kd4iuBlQHGVJ8xKmjtZFvcBOQoCWnrge4Y1w9FX9LnQRNtuQ7x7XM3VGumyuKtkrbCWKUPd5lqxVdMqe1H+EGQTfxsyElXeAthY7sTb39BNZwQoPtRYz0W+gxEyf+Q= ; Received: from unknown (HELO ?75.7.236.228?) (jekillen@prodigy.net@75.7.236.228 with plain) by smtp113.sbc.mail.mud.yahoo.com with SMTP; 2 Mar 2007 01:06:29 -0000 X-YMail-OSG: ViP3gvsVM1lcHgYv5JG5IuMqbZxoWb3wTeZDwe4.jdUg7atRXCH.nHN8qkhT7xE0PqzqZi1cejkOrdPqsqREOo9CT1Qv5Ve8yk9BRu07TBzVbGYd6kJ_nouEo2bDGQfKG6Na8Z8MMr9f3oQ- In-Reply-To: References: <539c60b90703010849x33dd4bbbt8f6ca6aa0c8e83a0@mail.gmail.com> <20070301165055.638b0a06.wmoran@collaborativefusion.com> <44r6s8y4o5.fsf@be-well.ilk.org> Mime-Version: 1.0 (Apple Message framework v622) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <2dac75d59286fc9c0481d6dc7ca29e16@prodigy.net> Content-Transfer-Encoding: 7bit From: jekillen Date: Thu, 1 Mar 2007 17:06:09 -0800 To: Ivan Voras X-Mailer: Apple Mail (2.622) Cc: FreeBSD Mailing List Subject: Re: defrag 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: Fri, 02 Mar 2007 01:06:31 -0000 On Mar 1, 2007, at 2:56 PM, Ivan Voras wrote: > Lowell Gilbert wrote: > >> If you know the standard computer science terminology, it can be >> described quite tersely. UFS fragmentation is a way of avoiding >> internal fragmentation from wasting too much space. MS-DOS-FS >> fragmentation is an example of external fragmentation in the storage >> space. They don't really have anything to do with each other. > > It looks like I actually AM arguing about semantics here: > > "UFS fragmentation" refers to dividing blocks (e.g. 16KB in size) into > block fragments (e.g. 2KB in size) that can be allocated separately in > special circumstances (which all boil down to: at the end of files). > This is done to lessen the effect of internal fragmentation. > > "Fragmentation" without "UFS" prefix, as mostly used today (and which > I > believe it's how the original poster understands it) refers to dividing > files into non-continuous regions, i.e. external fragmentation. > > Correct so far? > > "% fragmentation" message from fsck cannot refer to internal > fragmentation as the numbers don't add up, so it almost certainly > refers > to external fragmentation. > This discussion has been about UFS vs MS file system. But I have been using Macs and have run file system utilities, Norton, and watched it defrag a Mac disc. I am just curious as to how the HFS and HFS+ file systems fit into this picture. Particularly since OSX is essentially a Unix 'like' system but still uses HFS+ Just for some perspective and idle curiosity. Thanks Jeff K