From owner-freebsd-questions@FreeBSD.ORG Fri Mar 2 16:15:08 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 0F5C616A400 for ; Fri, 2 Mar 2007 16:15:08 +0000 (UTC) (envelope-from jerrymc@gizmo.acns.msu.edu) Received: from gizmo.acns.msu.edu (gizmo.acns.msu.edu [35.8.1.43]) by mx1.freebsd.org (Postfix) with ESMTP id D503513C4AC for ; Fri, 2 Mar 2007 16:15:07 +0000 (UTC) (envelope-from jerrymc@gizmo.acns.msu.edu) Received: from gizmo.acns.msu.edu (localhost [127.0.0.1]) by gizmo.acns.msu.edu (8.13.6/8.13.6) with ESMTP id l22GCQXI090243; Fri, 2 Mar 2007 11:12:26 -0500 (EST) (envelope-from jerrymc@gizmo.acns.msu.edu) Received: (from jerrymc@localhost) by gizmo.acns.msu.edu (8.13.6/8.13.6/Submit) id l22GCPYN090242; Fri, 2 Mar 2007 11:12:25 -0500 (EST) (envelope-from jerrymc) Date: Fri, 2 Mar 2007 11:12:25 -0500 From: Jerry McAllister To: Ivan Voras Message-ID: <20070302161225.GB90036@gizmo.acns.msu.edu> References: <539c60b90703010849x33dd4bbbt8f6ca6aa0c8e83a0@mail.gmail.com> <20070301192109.A24369@chylonia.3miasto.net> <20070302085100.125cf488@localhost> <20070301221738.GA86154@gizmo.acns.msu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Cc: freebsd-questions@freebsd.org 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 16:15:08 -0000 On Fri, Mar 02, 2007 at 02:17:31AM +0100, Ivan Voras wrote: > Jerry McAllister wrote: > > > Well, it would do some, but for the greatest effect, you would need: > > dump + rm -rf * + restore > > This is nitpicking so ignore it: deleting all files on UFS2 volume won't > restore it to it's pristine state because inodes are lazily initialized. > It doesn't have anything to do with fragmentation, but will make fsck > run a little longer. > True it wouldn't be quite pristine because files would have different inodes assigned when they get reloaded than they might have if it was newfs-ed before reloading. That might make fsck run a tiny bit slower. But it wouldn't be any difference for a running system file access. On the other hand, doing all this either way wouldn't make any difference in performance for file access in a running system because so-called fragmentation is not an issue in the UNIX file system - except in the small possibility that it might make a bit of difference in a file system filled to capacity, well in to the reserve where non-root processes are not allowed to write anyway. I don't know just how close to absolutely full you have to get to see any difference, but it is beyond what users would normally get to. ////jerry