From owner-freebsd-questions@FreeBSD.ORG Fri Dec 2 12:37:30 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 78C2316A41F for ; Fri, 2 Dec 2005 12:37:30 +0000 (GMT) (envelope-from wojtek@tensor.3miasto.net) Received: from chylonia.3miasto.net (chylonia.3miasto.net [213.192.74.6]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0D3DF43D5F for ; Fri, 2 Dec 2005 12:37:28 +0000 (GMT) (envelope-from wojtek@tensor.3miasto.net) Received: from chylonia.3miasto.net (localhost [127.0.0.1]) by chylonia.3miasto.net (8.13.4/8.13.4) with ESMTP id jB2CbKe6053949 for ; Fri, 2 Dec 2005 13:37:20 +0100 (CET) (envelope-from wojtek@tensor.3miasto.net) Received: from localhost (wojtek@localhost) by chylonia.3miasto.net (8.13.4/8.13.4/Submit) with ESMTP id jB2CbJVG053946 for ; Fri, 2 Dec 2005 13:37:20 +0100 (CET) (envelope-from wojtek@tensor.3miasto.net) X-Authentication-Warning: chylonia.3miasto.net: wojtek owned process doing -bs Date: Fri, 2 Dec 2005 13:37:19 +0100 (CET) From: Wojciech Puchar X-X-Sender: wojtek@chylonia.3miasto.net To: freebsd-questions@freebsd.org Message-ID: <20051202132526.I52820@chylonia.3miasto.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Subject: a bit of FFS questions 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 Dec 2005 12:37:30 -0000 can someone help me. 1) newfs -a successfully creates the filesystem but dumpfs shows: . . . maxbsize 16384 maxbpg 2048 maxcontig 16 contigsumsize 16 what's the difference between maxcontig and contigsumsize? will FreeBSD kernel actually make user of maxcontig >16 (with MAXPHYS>128k it make sense) 2) -b - does it make real sense? i tested with large files and it CPU load is small anyway, while transfer speed is the same. the answer may depend on answer for question 1 however. 3) -i - it would save space to use -i 16384, 32768 or more, and reduce fsck times. but if inode counts is closely tailored to amount of files, will it slow down filesystem and how much? i think if something like half or less inodes are allocated, OS have higher degree of freedom of where to allocate inode. but i imagine too that having even more free inodes doesn't make things. what is the ratio of used to free inodes, below which there will be just wasted space? 4) -o space/time - in my tests i can't see much difference in CPU load, maybe on 386 it was a difference but not on Athlon64 or P4. isn't -o space better to be always used? 5) -m - does -m change anything in FFS algorithms, or it's just a quota? i would prefer to set it low just in case of urgent need of space, while trying to maintain 8-10 free space at normal operation. am i right?