From owner-freebsd-fs@FreeBSD.ORG Thu Nov 13 16:57:48 2008 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 E284B1065670 for ; Thu, 13 Nov 2008 16:57:48 +0000 (UTC) (envelope-from toasty@dragondata.com) Received: from tokyo01.jp.mail.your.org (tokyo01.jp.mail.your.org [204.9.54.5]) by mx1.freebsd.org (Postfix) with ESMTP id AA1418FC19 for ; Thu, 13 Nov 2008 16:57:48 +0000 (UTC) (envelope-from toasty@dragondata.com) Received: from tokyo01.jp.mail.your.org (localhost.your.org [127.0.0.1]) by tokyo01.jp.mail.your.org (Postfix) with ESMTP id 8542D2AD557B; Thu, 13 Nov 2008 16:57:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=dragondata.com; h=cc :message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references; s=selector1; bh=rbWyn/sb4c5wkJ0A3/Lg/huhoRU=; b=3l7p7tIOZJxeEe4 GZdm8LRCgXEOaIUDNfJbcQNQLRku8XHf80Oe4NRmjSPQ7fA8klg/GSRVFwt5J0le dZmsXfQfhTtj9y+B1qsyy9xBu2mIi6XWxqFqD+JjzCh2X2vkZpQk+4ElOKIbVzCx 2sqkmoFGch3hMu+6pYAq5twifx5g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=dragondata.com; h=cc:message-id :from:to:in-reply-to:content-type:content-transfer-encoding :mime-version:subject:date:references; q=dns; s=selector1; b=tlN GHF1Ed7rMvvmAyOliMVPTnLcBi1kT3LNkCoi9dcs09tMUxxXtR6I2eoUG1BDl1P5 +X4Dr6nFZPRNBAQ8r3Gp4ubsCNiD9MPwyPuiZNxO6K6P0yScEbZpqQek02AyXqXy jzCzEmZ8ORQt561K9kEaLt/Nn1oYU3vCfeCy2LFM= Received: from mail.your.org (server3-a.your.org [64.202.112.67]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by tokyo01.jp.mail.your.org (Postfix) with ESMTPS id 5A8962AD557A; Thu, 13 Nov 2008 16:57:47 +0000 (UTC) Received: from [216.14.99.244] (unknown [216.14.99.244]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mail.your.org (Postfix) with ESMTPSA id 43808A0A406; Thu, 13 Nov 2008 16:57:11 +0000 (UTC) Message-Id: From: Kevin Day To: =?ISO-8859-1?Q?Javier_Mart=EDn_Rueda?= In-Reply-To: <491C51A7.8080000@diatel.upm.es> Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Apple Message framework v929.2) Date: Thu, 13 Nov 2008 10:57:44 -0600 References: <6EEFB17C-10DF-4CCD-AB07-83B4B75D033F@dragondata.com> <491C51A7.8080000@diatel.upm.es> X-Mailer: Apple Mail (2.929.2) Cc: freebsd-fs@freebsd.org Subject: Re: UFS Snapshot lock time 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: Thu, 13 Nov 2008 16:57:49 -0000 On Nov 13, 2008, at 10:11 AM, Javier Mart=EDn Rueda wrote: > Just a word of caution: I used to do this in some different machines =20= > (taking periodic snapshots and leaving a few around), and after a =20 > few days or weeks the system would lock up. Any process accessing =20 > the filesystem would block in "ufs" or something like that. After =20 > rebooting, fsck would report fatal errors and I had to do fsck -y in =20= > order to fix them with plenty of scary messages about truncated =20 > inodes, unexpected inconsistencies, and so on. This happened in =20 > several 6.x releases, on different machines, and both under i386 or =20= > amd64. Eventually, I gave up. > > I strongly suggest you try taking hourly snapshots in a non-=20 > production system first for a few weeks, and see if you experience =20 > this kind of problems. Sorry to be a party-pooper. > > It looks as if keeping more than one snapshot eventually is =20 > problematic. Taking single snapshots for dump has never been a =20 > problem, though. > We definitely saw this problem in 6.x. Any reboot after a snapshot =20 would be a mess of fsck fun for a few hours, usually resulting in us =20 losing stuff. But, 7.0 has cured that for me. So far hourly/daily snapshots on any of the 7.0 boxes we've tried it =20 on has worked, it's just so slow it's unusable. I'd like to think =20 it's just being slow because it's being very careful. :) -- Kevin