From owner-freebsd-hackers@FreeBSD.ORG Tue May 20 15:57:19 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 32FBEE73 for ; Tue, 20 May 2014 15:57:19 +0000 (UTC) Received: from mail-ie0-x242.google.com (mail-ie0-x242.google.com [IPv6:2607:f8b0:4001:c03::242]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0797823F5 for ; Tue, 20 May 2014 15:57:18 +0000 (UTC) Received: by mail-ie0-f194.google.com with SMTP id tp5so193472ieb.1 for ; Tue, 20 May 2014 08:57:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=J/fwCbiIYdTtwgghBqcfgoV5KQnCOnsZjlDVNDzsIFs=; b=fzIqdqWhsohcM0BsD2LypdofZd4x2xHTyWcr2aw5JwHmWYZs38hEAbPXyTSzraiGJk HYXfqaJabJtpiUlrUb0tdT1BzGR+0B225Fn0g2gwRQmgJA5oDH5LE9G3xJKV2J6YBG0r GpNHqvRcaGSbLMf9XjkuoiPFJQeBX0xwdj4jHmNf4N5Bq34mhGtjP8qUIZ6eKiTHHmNh hqhCMiqLwPBQqT8TCcUUO3RRjLyAjKtfoiZkuAOSFf+o3J48M0EW6O+EhSSMNowjTVsD +RVss5XvCnAle215qtyQQhfqms++7xtpasCEtspjBEyrOcYlVHxEYDGX7l3QpiUKtUN5 pgnQ== MIME-Version: 1.0 X-Received: by 10.50.82.105 with SMTP id h9mr6235715igy.6.1400601438256; Tue, 20 May 2014 08:57:18 -0700 (PDT) Received: by 10.64.250.101 with HTTP; Tue, 20 May 2014 08:57:18 -0700 (PDT) Date: Tue, 20 May 2014 08:57:18 -0700 Message-ID: Subject: Re: hard reset impacts on ufs file system From: Dieter BSD To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 May 2014 15:57:19 -0000 >> Hard reset examined on freebsd 8.3. after reboot libncurses.so.8 was 0 >> byte. Are there any complaints in /var/log/* ? e.g. from fsck, or about the disk/controller? > My original guess as to why this seemed to always happen to > libraries was that the system damaged their entries when > attempting to update the atime on the files. Plenty of other files get accessed, and thus their atimes updated. If this is common for libraries but not other files, then the cause is likely something else. I've been using FFS since 1984 and I don't recall ever seeing a file get truncated to 0 length. SCSI, PATA, SATA, and those horrid USB-to- *ATA bridges that do not let you turn off the disk's write cache. Note that PATA does not do error checking on the address, so it can in theory write the correct data to the wrong sector. No SSD. Never turned off atime.