From owner-freebsd-stable@FreeBSD.ORG Mon Sep 1 22:36:33 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7436D1065672 for ; Mon, 1 Sep 2008 22:36:33 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA06.westchester.pa.mail.comcast.net (qmta06.westchester.pa.mail.comcast.net [76.96.62.56]) by mx1.freebsd.org (Postfix) with ESMTP id 16F0D8FC25 for ; Mon, 1 Sep 2008 22:36:32 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA10.westchester.pa.mail.comcast.net ([76.96.62.28]) by QMTA06.westchester.pa.mail.comcast.net with comcast id 9YsV1a0080cZkys56acYdg; Mon, 01 Sep 2008 22:36:32 +0000 Received: from koitsu.dyndns.org ([67.180.253.227]) by OMTA10.westchester.pa.mail.comcast.net with comcast id 9acW1a0024v8bD73WacWl1; Mon, 01 Sep 2008 22:36:31 +0000 X-Authority-Analysis: v=1.0 c=1 a=pCr_F2gNLvkA:10 a=2kEG5XAC4tcA:10 a=QycZ5dHgAAAA:8 a=RSDXKoDseaxdrUXAbecA:9 a=30igA5C5co8REFt9nbt_okaN544A:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id DDF2317B84E; Mon, 1 Sep 2008 15:36:29 -0700 (PDT) Date: Mon, 1 Sep 2008 15:36:29 -0700 From: Jeremy Chadwick To: Kevin Oberman Message-ID: <20080901223629.GA18346@icarus.home.lan> References: <200809011336.m81Da5BT046532@lava.sentex.ca> <20080901160013.0005F4500F@ptavv.es.net> <20080901213856.GA17155@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080901213856.GA17155@icarus.home.lan> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: Derek =?iso-8859-1?B?S3VsacU/c2tp?= , Michael , freebsd-stable@freebsd.org Subject: Re: bin/121684: : dump(8) frequently hangs X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Sep 2008 22:36:33 -0000 On Mon, Sep 01, 2008 at 02:38:56PM -0700, Jeremy Chadwick wrote: > The problem was that UFS2 snapshot generation, over time, becomes > slower and slower to generate (this is what dump does on UFS2 systems, > with or without the -L flag), and is a known design issue. Clarification: dump on UFS2 (without -L flag) will NOT generate a snapshot, but emits a nasty message telling you to use -L on live filesystems which are mounted r/w. I'm wondering if people experiencing this problem are using the -L flag or not (I'm betting most are). If you are, try removing it and see if things improve. But if I remember correctly, there's also a risk involved with this: not generating a snapshot on UFS2 means your dump could actually contain "half-written" files (e.g. when you recover, you might only have a partial file for something that was being written at the time of dump). -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |