From owner-freebsd-fs@FreeBSD.ORG Wed Aug 12 21:19:56 2009 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 BC4B11065677; Wed, 12 Aug 2009 21:19:56 +0000 (UTC) (envelope-from nafzal@hotmail.com) Received: from col0-omc1-s14.col0.hotmail.com (col0-omc1-s14.col0.hotmail.com [65.55.34.24]) by mx1.freebsd.org (Postfix) with ESMTP id AEC038FC5F; Wed, 12 Aug 2009 21:19:55 +0000 (UTC) Received: from COL111-W50 ([65.55.34.8]) by col0-omc1-s14.col0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 12 Aug 2009 14:15:05 -0700 Message-ID: X-Originating-IP: [192.55.54.38] From: Naeem Afzal To: Date: Wed, 12 Aug 2009 21:15:05 +0000 Importance: Normal In-Reply-To: <20090812052814.GD1600@garage.freebsd.pl> References: <20090811191837.GB66530@keira.kiwi-computer.com> <20090812052814.GD1600@garage.freebsd.pl> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 12 Aug 2009 21:15:05.0905 (UTC) FILETIME=[F6D82A10:01CA1B91] Cc: freebsd-fs@freebsd.org Subject: RE: filesystem size after newfs X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Aug 2009 21:19:57 -0000 Block size is set to 4K=2C did you mean fragment size should be 4K too? Are= you saying that for each block of 512b there is 32b for space consumed for= hash? Is this only when using authentication algorithm? regardsnaeem > > To ensure atomicity of operations=2C geli stores hashes in the same > sector as the data. Creating geli providers with block size of 512 bytes > is very inefficient. It will consume two sectors for each sector=2C which > looks like this: > > 1 512b of data -----> 480b for data + 32b for hash > 2 32b for data + 32b for hash + 448b unused > > The most optimal block size for geli provider is 4kB=2C it consumes one > extra sector for every 8 sectors: > > 1 512b of data -----> 480b for data + 32b for hash > 2 512b of data 480b for data + 32b for hash > 3 512b of data 480b for data + 32b for hash > 4 512b of data 480b for data + 32b for hash > 5 512b of data 480b for data + 32b for hash > 6 512b of data 480b for data + 32b for hash > 7 512b of data 480b for data + 32b for hash > 8 512b of data 480b for data + 32b for hash > 9 256b for data + 32b for hash + 224 unused > > -- > Pawel Jakub Dawidek http://www.wheel.pl > pjd@FreeBSD.org http://www.FreeBSD.org > FreeBSD committer Am I Evil? Yes=2C I Am! _________________________________________________________________ Express your personality in color! Preview and select themes for Hotmail=AE= .=20 http://www.windowslive-hotmail.com/LearnMore/personalize.aspx?ocid=3DPID233= 91::T:WLMTAGL:ON:WL:en-US:WM_HYGN_express:082009=