From owner-freebsd-questions@FreeBSD.ORG Thu Jan 28 16:42:39 2010 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 1EE68106566B for ; Thu, 28 Jan 2010 16:42:39 +0000 (UTC) (envelope-from nvass9573@gmx.com) Received: from mailout-eu.gmx.com (mailout-eu.gmx.com [213.165.64.42]) by mx1.freebsd.org (Postfix) with SMTP id 698F28FC0A for ; Thu, 28 Jan 2010 16:42:38 +0000 (UTC) Received: (qmail invoked by alias); 28 Jan 2010 16:42:36 -0000 Received: from adsl-144.79.107.94.tellas.gr (EHLO [192.168.73.195]) [79.107.94.144] by mail.gmx.com (mp-eu001) with SMTP; 28 Jan 2010 17:42:36 +0100 X-Authenticated: #46156728 X-Provags-ID: V01U2FsdGVkX1+OBQgJi+WOvRZNxsIeMNIet3bxI3hEm63K1/NGmG x/zt/IAKJDCsYh Message-ID: <4B61BE70.1090109@gmx.com> Date: Thu, 28 Jan 2010 18:42:24 +0200 From: Nikos Vassiliadis User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.5) Gecko/20091204 Thunderbird/3.0 MIME-Version: 1.0 To: "freebsd-questions@FreeBSD.org" Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.64000000000000001 Subject: gjournal on compact flash 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: Thu, 28 Jan 2010 16:42:39 -0000 Hi, I am using a 40MB journal on a 500MB compact flash. Would that be sane, or I am causing more harm than good? My concerns are: 1) wear leveling. The journal is on specific part of the "disk" writing again and again. That should be handled by the CF itself. Though I am not sure it does a good job??? 2) I do care about ungraceful power cycles and I've seen posts on the net, mentioning: > More, If > you interrupt power at arbitrary times while the device is writing, > you can lose the integrity of the file system being modified. The loss > is not limited to the 512 byte sector being modified, as it generally > is with rotating disks; you can lose an entire erase block, maybe 64K > at once. I guess the above comment renders the use of a journaling filesystem useless. But, doing some naive tests, power cycling the machine while writing and checksumming the data after fsck in preen mode, revealed no error. Thanks in advance for any insights, Nikos