From owner-freebsd-questions@FreeBSD.ORG Fri Sep 21 23:03:19 2007 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 B6C2D16A418 for ; Fri, 21 Sep 2007 23:03:19 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.bluestop.org (muon.bluestop.org [80.68.94.188]) by mx1.freebsd.org (Postfix) with ESMTP id 8528A13C47E for ; Fri, 21 Sep 2007 23:03:19 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.draftnet (cran1.demon.co.uk [80.177.26.208]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by muon.bluestop.org (Postfix) with ESMTP id E906930122; Sat, 22 Sep 2007 00:03:17 +0100 (BST) Message-ID: <46F44D2A.5080206@cran.org.uk> Date: Sat, 22 Sep 2007 00:00:58 +0100 From: Bruce Cran User-Agent: Thunderbird 2.0.0.6 (X11/20070809) MIME-Version: 1.0 To: John Andrewartha References: <7f28909c2f575ccd98796e2af18d4e05@prodigy.net> <20070920193234.K4602@wojtek.tensor.gdynia.pl> <20070921154124.37d20c19@meijome.net> <200709211803.34234.mulga@flinders.homeunix.org> In-Reply-To: <200709211803.34234.mulga@flinders.homeunix.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: Hard drive RPM 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, 21 Sep 2007 23:03:19 -0000 John Andrewartha wrote: > When you format a disk a percentage of the disk is reserved for a map so your > file can be found. > On a UFS it is called the SUPER BLOCKS a master and at least one slave. > > Typically these blocks will take up to 8% or there abouts of the disk. > > BTW I am not shouting when "SUPER BLOCKS' that's how it's written. > > In a root shell type fsck and watch the screen. > > For more info dig into you docs usually /share/doc or usr/doc there where some > really good docs on the UFS By default 8% of the disk is also reserved for use by the superuser: this extra space isn't displayed in the "Avail" column of df, so when the disk is really full (i.e the root user has filled the disk) it will show negative values. The amount of space reserved can be changed using tunefs(8). -- Bruce Cran