From owner-freebsd-questions@FreeBSD.ORG Sun Apr 5 22:24:38 2009 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 830F51065673 for ; Sun, 5 Apr 2009 22:24:38 +0000 (UTC) (envelope-from illoai@gmail.com) Received: from qw-out-2122.google.com (qw-out-2122.google.com [74.125.92.24]) by mx1.freebsd.org (Postfix) with ESMTP id 386B88FC14 for ; Sun, 5 Apr 2009 22:24:37 +0000 (UTC) (envelope-from illoai@gmail.com) Received: by qw-out-2122.google.com with SMTP id 9so1439833qwb.7 for ; Sun, 05 Apr 2009 15:24:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=5HN47BxIe6Yj7NXLoywQAnbbjfGAh4jTzUU6oCABNDE=; b=wWektV8G0YdPZ48Tf5S6GrrDl9PTYHujIB7zL3vpT7yHmwhPhTQNWV2ccCgSWAiOg/ ikyzMtT1uxzuNtdoCwZqKR3NM18UhgLTmS8H9bsaYgw5omHGqeAeV1qc+Z+etT4GjRSm o+ChRZlDoCM90x9GQSD901G3Jsdm3yKJv8zhU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=ZFYYcpuAell5sfo8y6Oeyor3usA0fjFvC/IHfBJNiMkEQd9hAXZjatM2pcjkTmGnBK HM2Xn0T2mhIcccoAzOcKi/x1czUIl4vYN9uw6xMu5eMlbLxQWdtJCMDIdpOLQnIFIEee 5vTp+OiKUEQwKOwZ7uzFfcfNAAMLu0lg6DhlE= MIME-Version: 1.0 Received: by 10.229.94.129 with SMTP id z1mr791432qcm.22.1238970277446; Sun, 05 Apr 2009 15:24:37 -0700 (PDT) In-Reply-To: References: <200903311657.n2VGvLE8010101@lurza.secnetix.de> Date: Sun, 5 Apr 2009 18:24:37 -0400 Message-ID: From: "illoai@gmail.com" To: utisoft@gmail.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: Wojciech Puchar , olli@lurza.secnetix.de, freebsd-questions@freebsd.org Subject: Re: Question about forcing fsck at boottime 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: Sun, 05 Apr 2009 22:24:39 -0000 2009/4/5 Chris Rees : > 2009/3/31 Oliver Fromme : >> Chris Rees wrote: >> =A0> 2009/3/31 Wojciech Puchar : >> =A0> > >> =A0> > IMHO this background fsck isn't good idea at all >> =A0> >> =A0> Why? >> >> Google "background fsck damage". >> >> I was bitten by it myself, and I also recommend to turn >> background fsck off. =A0If your disks are large and you >> can't afford the fsck time, consider using ZFS, which >> has a lot of benefits besides not requiring fsck. >> >> Best regards >> =A0 Oliver >> > > Right... You were bitten by background fsck, what _exactly_ happened? > All the 'problems' here associated with bgfsck are referring to > FreeBSD 4 etc, or incredibly vague anecdotal evidence. Have you > googled for background fsck damage? Nothing (in the first two pages at > least) even suggests that background fsck causes damage. > > Erik Trulsson wrote: >> Normal PATA/SATA disks with write caching enabled (which is the default)= do >> not provide these guarantees. =A0Disabling write caching on will make th= em >> adhere to the assumptions that soft updates make, but at the cost of a >> severe performance penalty when writing to the disks. > >> In short therefore on a 'typical' PC you can fairly easily get errors on= a >> filesystem which background fsck cannot handle. > > What do you mean by handle? Sure, it won't fix them, but it'll at > least detect them. The chances of actually having a problem are slim, > anyway, and it won't cause any damage either. > > This is exactly my experience: maybe three times in years of various power failures and hardware barfs have I had the background fsck tell me to run fsck manually. And that is the entire extent of the "failure". The system was running normally, if a bit slowly from the fsck itself, and the worst result was a disappeared /var/db/pkg directory (which had nothing to do with fsck being in the background on restart). --=20 --