From owner-freebsd-questions@FreeBSD.ORG Mon Oct 14 17:16:24 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 94810D3F for ; Mon, 14 Oct 2013 17:16:24 +0000 (UTC) (envelope-from tomek.cedro@gmail.com) Received: from mail-qc0-x232.google.com (mail-qc0-x232.google.com [IPv6:2607:f8b0:400d:c01::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 5525E2887 for ; Mon, 14 Oct 2013 17:16:24 +0000 (UTC) Received: by mail-qc0-f178.google.com with SMTP id x19so5695qcw.37 for ; Mon, 14 Oct 2013 10:16:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=DpZWwl6b1wLipcgUSQAfNJdQ4/zzpc7oi6D98N7LvEM=; b=K7DDQ86QpMFVvNld8hHTcZlf341M28YRoaosEn73M/Cm+aCIW6CbqGBr2sWHbOmdIl 0KL+Jx5A6YOfl+kf/tbiZZtkMRLFkqCv5HcUCPwhRXMO5hd+O1YLNGeRLKP8UT1/7QS6 BvtfOIdVNMa1jjXzkDpe89mNPsLcMlCBoT1y8VhBKPMTW2LO22qgxRjGLfVQUwd9Azz5 ZBSePXOAi7AzlHlJWj9EvcZXIz3JtWH55PxzbgWeEHewS9vj/oVbf2vns5IgV6wZ0KUh TPTfxLn3IvVEGNvBoM//5Vx2EYs3TKQQ/2yFx6nDt6eBcjeZT/e+FmVpiRRnrEHhoyOg Wy4Q== MIME-Version: 1.0 X-Received: by 10.224.171.67 with SMTP id g3mr36753904qaz.13.1381770983508; Mon, 14 Oct 2013 10:16:23 -0700 (PDT) Sender: tomek.cedro@gmail.com Received: by 10.49.16.170 with HTTP; Mon, 14 Oct 2013 10:16:23 -0700 (PDT) In-Reply-To: <525C2554.7080203@pchotshots.com> References: <525A6831.5070402@gmail.com> <20131014133953.58f74659@gumby.homeunix.com> <525C1D1C.9050708@gmail.com> <525C2554.7080203@pchotshots.com> Date: Mon, 14 Oct 2013 19:16:23 +0200 X-Google-Sender-Auth: 1gbhhwe_Zq9m4pSLloosOlKDZJ0 Message-ID: Subject: Re: SU+J Lost files after a power failure From: CeDeROM To: Brad Mettee Content-Type: text/plain; charset=UTF-8 Cc: David Demelier , Adam Vande More , FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Oct 2013 17:16:24 -0000 On Mon, Oct 14, 2013 at 7:09 PM, Brad Mettee wrote: > On 10/14/2013 12:50 PM, CeDeROM wrote: >> Then why random files gets damaged as well even they are not >> accessed/written on power loss? :-) > > Random files can be affected because the sectors of the hard disk containing > the directory entries for those files, not the file data itself, may be > damaged (ie: the directory was in the process of being written OR the > pointer to that SECTOR was in the process of being written). > > It doesn't mean a file was in active use, just that a chunk of the disk with > data relevant to that file was. Keep in mind, one sector of disk may have > data for a dozen files in it (or more). Damage doesn't have to occur because > a given file was in use at the time of a crash. Isn't there Journal to prevent and reverse such damage? > If your power grid is prone to failures or blips, I strongly suggest > investing in a UPS. I have UPS in my desktop and also I am working on a laptop, so the power supply is not the only possible cause of system crash.. this may be faulty driver, hardware failure, kernel panic, etc. -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info