From owner-freebsd-fs@FreeBSD.ORG Wed Sep 26 03:19:02 2007 Return-Path: Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F0D2716A419 for ; Wed, 26 Sep 2007 03:19:02 +0000 (UTC) (envelope-from rick@kiwi-computer.com) Received: from kiwi-computer.com (keira.kiwi-computer.com [63.224.10.3]) by mx1.freebsd.org (Postfix) with SMTP id 570AC13C45A for ; Wed, 26 Sep 2007 03:19:02 +0000 (UTC) (envelope-from rick@kiwi-computer.com) Received: (qmail 34528 invoked by uid 2001); 26 Sep 2007 03:12:20 -0000 Date: Tue, 25 Sep 2007 22:12:20 -0500 From: "Rick C. Petty" To: Bruce Evans Message-ID: <20070926031219.GB34186@keira.kiwi-computer.com> References: <46F3A64C.4090507@fluffles.net> <46F3B4B0.40606@freebsd.org> <20070921131919.GA46759@in-addr.com> <20070921133127.GB46759@in-addr.com> <20070922022524.X43853@delplex.bde.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070922022524.X43853@delplex.bde.org> User-Agent: Mutt/1.4.2.1i Cc: freebsd-fs@FreeBSD.org Subject: Re: Writing contigiously to UFS2? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: rick-freebsd@kiwi-computer.com List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Sep 2007 03:19:03 -0000 On Sat, Sep 22, 2007 at 04:10:19AM +1000, Bruce Evans wrote: > > of disk can be mapped. I get 180MB in practice, with an inode bitmap > size of only 3K, so there is not much to be gained by tuning -i but I disagree. There is much to be gained by tuning -i: 224.50 MB per CG vs. 183.77 MB.. that's a 22% difference. However, the biggest gain by tuning -i is the loss of extra (unused) inodes. Care should be used with the -i option-- running out of inodes when you have gigs of free space could be very frustrating. But I newfs all my volumes knowing an approximate inode density based on already-existing files and a minor fudge factor. The only time I ran out of inodes with this method was due to a calculation error on my part. > more to be gained by tuning -b and -f (several doublings are reasonable). I completely agree with this. It's unfortunate that newfs doesn't scale the defaults here based on the device size. Before someone dives in and commits any adjustments, I hope they do sufficient testing and post their results on this mailing list. -- Rick C. Petty