From owner-freebsd-fs@FreeBSD.ORG Wed Jun 24 09:28:23 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 10286106564A for ; Wed, 24 Jun 2009 09:28:23 +0000 (UTC) (envelope-from numisemis@yahoo.com) Received: from web37303.mail.mud.yahoo.com (web37303.mail.mud.yahoo.com [209.191.90.246]) by mx1.freebsd.org (Postfix) with SMTP id C3D3B8FC17 for ; Wed, 24 Jun 2009 09:28:22 +0000 (UTC) (envelope-from numisemis@yahoo.com) Received: (qmail 22549 invoked by uid 60001); 24 Jun 2009 09:28:22 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1245835702; bh=i6QwPKOz3E0UPqLKXsaYRiuqjHhuCcYrhy4hqwuOMLo=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=ufArkBXq8gUMf4JPX3SWaQ5ehzHukWtuv0V96ZQ4tUwW93MHD5f4cOWC2Ecd33wL7GjxeteObY9kli9REDbQcBSMem9qb9LPXcjA6egVbPdcajoA6HiW9FbGXg7S3guRhkm9rSpkVfmXTR1QqbKWh634H1EZpuyje9OMdmOpoXc= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=L1TPOcN4J/fR9e6eorGeK4Od0wSDpKoc1n1M3sgXayCzuKR0LxXfxNol06+3W4r6bDW943zNEoSzRw17kGRLGjmtiGMlwhrxraqQnBGPShUhz6niC5x2CuoMoxLmPTyRwasbp99FTHuU32hUpjhUNxDXiLKMSxmIsmuWT39KpR4=; Message-ID: <130804.21855.qm@web37303.mail.mud.yahoo.com> X-YMail-OSG: hJn6nTsVM1nIszhbA.PJqsGl.jADvL8SkDsjzROYbeaDEL_CfZs6qfmWyHyHsLWztMz7VlrC.z.rLPP1A8Db.mNm34wolLa_HsziDpm0XPkERWFmGzMox0n__RHIv5idGOtaPfT9Vsryxj8.YM5Z4iOkqaNtT1UdOCm5tX_tPI1gwH.gdV6WdZcJyfUBACcbigPaOPKVrx.bVGd5Mvk50X7S2LuK6WiDYzUFJI0s_wotmzjJ4IR_ee0I6SoxS7aEhc3R9U_PIfA8fgWh_27xzqBezQ980dSr5wkeuL3rPMcNiJG0jCdsx5wFpAb6wzCvesf5NDgu5tjzV3GqkDvGffk- Received: from [213.147.110.159] by web37303.mail.mud.yahoo.com via HTTP; Wed, 24 Jun 2009 02:28:21 PDT X-Mailer: YahooMailRC/1277.43 YahooMailWebService/0.7.289.15 References: <4A41E073.70902@mail.ru> Date: Wed, 24 Jun 2009 02:28:21 -0700 (PDT) From: Simun Mikecin To: rihad In-Reply-To: <4A41E073.70902@mail.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-fs@freebsd.org Subject: Re: Is it preferable to use the sync command? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Jun 2009 09:28:23 -0000 rihad wrote: > Having experienced a FreeBSD 5.1 crash due to power failure (despite using a UPS) resulting in massive /etc corruption and data loss, in order to minimize future risks should I: > 0) tweak (decrease) these default sysctls: > kern.filedelay: 30 > kern.dirdelay: 29 > kern.metadelay: 28 > 1) mount the root FS with soft-updates enabled (left as disabled in sysinstall by default due to known reasons) > 2) setup a cron job calling /bin/sync every minute > I somehow feel that turning soft-updates on would do the trick (it is not normally written to and has plenty of free space anyway). Do you use ATA or SCSI? Turning soft-updates on for SCSI should do the trick. Since there is no support for gjournal and/or ZFS on 5.1, for ATA only real solution would be disabling write-cache (which degrades performance): "sysctl hw.ata.wc=0".