From owner-freebsd-current@FreeBSD.ORG Sat Feb 7 06:37:20 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 10A6116A4CE for ; Sat, 7 Feb 2004 06:37:20 -0800 (PST) Received: from mail.sw-sec.de (mail.sw-sec.de [80.190.231.179]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8BA2E43D1F for ; Sat, 7 Feb 2004 06:37:19 -0800 (PST) (envelope-from h@schmalzbauer.de) Received: from cale.flintsbach.schmalzbauer.de (ppp-82-135-4-2.mnet-online.de [82.135.4.2]) (authenticated bits=0) by mail.sw-sec.de (8.12.10/8.12.10) with ESMTP id i17EbH0C054928; Sat, 7 Feb 2004 15:37:17 +0100 (CET) (envelope-from h@schmalzbauer.de) From: Harald Schmalzbauer To: Erik Trulsson , Stijn Hoop Date: Sat, 7 Feb 2004 15:37:08 +0100 User-Agent: KMail/1.5.4 References: <20040206072244.GT908@cirb503493.alcatel.com.au> <20040207131735.GA2803@pcwin002.win.tue.nl> <20040207141103.GA65140@falcon.midgard.homeip.net> In-Reply-To: <20040207141103.GA65140@falcon.midgard.homeip.net> X-Birthday: 06 Oktober 1972 X-Name: Harald Schmalzbauer X-Phone1: +49 (0) 163 555 3237 X-Phone2: +49 (0) 89 18947781 X-Address: Munich, 80686 X-Country: Germany MIME-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="Boundary-02=_cgPJA3bWjJHcuYi"; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <200402071537.16757@harrymail> cc: freebsd-current@freebsd.org Subject: Re: Reserved space (WAS: How to calculate bsdlabel size) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 07 Feb 2004 14:37:20 -0000 --Boundary-02=_cgPJA3bWjJHcuYi Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Description: signed data Content-Disposition: inline On Saturday 07 February 2004 15:11, Erik Trulsson wrote: > On Sat, Feb 07, 2004 at 02:17:35PM +0100, Stijn Hoop wrote: > > On Fri, Feb 06, 2004 at 01:57:11PM -0500, Garrett Wollman wrote: > > > < said: > > > > Does the algorithm(s) rely only on percentage of free > > > > space? On a five TB (netto) filesystem eigth percent > > > > is approx. 410 GB which seems quite alot. > > > > > > A good Data Structures text will prove to you that the efficiency of > > > hashing algorithms of the sort that the UFS block allocator uses > > > depends only on the occupancy ratio and not on the absolute number of > > > free hash slots. > > > > Which translates into what wrt this question? That the 8% of free space > > is really necessary for the UFS block allocator to function efficiently? > > Yes, that is exactly what it translates to. Hm, I don't really understand why, but anyway, what performance degradation= do=20 I have to expect when lowering it to 2%? =2DHarry --Boundary-02=_cgPJA3bWjJHcuYi Content-Type: application/pgp-signature Content-Description: signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (FreeBSD) iD8DBQBAJPgcBylq0S4AzzwRAruLAJ9KCHHucTwkysriaXEhN0FVttEcwACePUMU AfyhWvQoGxDUtTausLlWgbM= =NJlZ -----END PGP SIGNATURE----- --Boundary-02=_cgPJA3bWjJHcuYi--