From owner-freebsd-performance@FreeBSD.ORG Wed Sep 3 11:16:58 2003 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0D11716A4BF; Wed, 3 Sep 2003 11:16:58 -0700 (PDT) Received: from otter3.centtech.com (moat3.centtech.com [207.200.51.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 158EB43FDF; Wed, 3 Sep 2003 11:16:57 -0700 (PDT) (envelope-from anderson@centtech.com) Received: from centtech.com (neutrino.centtech.com [204.177.173.28]) by otter3.centtech.com (8.12.3/8.12.3) with ESMTP id h83IGtob047140; Wed, 3 Sep 2003 13:16:56 -0500 (CDT) (envelope-from anderson@centtech.com) Message-ID: <3F563014.5050504@centtech.com> Date: Wed, 03 Sep 2003 13:16:52 -0500 From: Eric Anderson User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Max Clark References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-hackers@freebsd.org cc: freebsd-performance@freebsd.org Subject: Re: 20TB Storage System (fsck????) X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Sep 2003 18:16:58 -0000 Max Clark wrote: > Ohh, that's an interesting snag. I was under the impression that 5.x w/ PAE > could address more than 4GB of Ram. > > - The PAE support allows FreeBSD machines to make use of more than 4 > gigabytes of RAM. This functionality was originally written by Jake > Burkholder under contract with DARPA and Network Associates Laboratories. > Additional changes for individual device drivers will follow in the coming > weeks. > > If fsck requires 700K for each 1GB of Disk, we are talking about 7GB of Ram > for 10TB of disk. Is this correct? Will PAE not function correctly to give > me 8GB of Ram? To check 10TB of disk? > > Is there anyway to bypass this requirement and split fsck into smaller > chunks? Being able to fsck my disk is kinda important. Is it possible for you to break up the 10TB partitions into 4TB partitions? If you could ccd those two 10TB RAIDs together into one 20TB ccd'd "drive", then partition that "drive" into 5 4TB chunks, you could get away with it knowing that an fsck would take a LONG time, and use up to 3GB of memory.. in theory. Eric -- ------------------------------------------------------------------ Eric Anderson Systems Administrator Centaur Technology All generalizations are false, including this one. ------------------------------------------------------------------