From owner-freebsd-stable@FreeBSD.ORG Wed Mar 25 16:45:43 2009 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 8B2B3106566C for ; Wed, 25 Mar 2009 16:45:42 +0000 (UTC) (envelope-from cpghost@cordula.ws) Received: from fw.farid-hajji.net (fw.farid-hajji.net [213.146.115.42]) by mx1.freebsd.org (Postfix) with ESMTP id 20DB38FC15 for ; Wed, 25 Mar 2009 16:45:42 +0000 (UTC) (envelope-from cpghost@cordula.ws) Received: from phenom.cordula.ws (phenom [192.168.254.60]) by fw.farid-hajji.net (Postfix) with ESMTP id 9007332681; Wed, 25 Mar 2009 17:45:39 +0100 (CET) Date: Wed, 25 Mar 2009 17:45:38 +0100 From: cpghost To: "Mikhail T." Message-ID: <20090325164538.GA6843@phenom.cordula.ws> References: <49C83673.3000604@aldan.algebra.com> <200903251232.11418.doconnor@gsoft.com.au> <49C99204.2050601@aldan.algebra.com> <200903251334.38350.doconnor@gsoft.com.au> <49C99FD2.50609@aldan.algebra.com> <49CA5602.9050001@aldan.algebra.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49CA5602.9050001@aldan.algebra.com> User-Agent: Mutt/1.5.19 (2009-01-05) Cc: freebsd-stable@freebsd.org Subject: Re: dump | restore fails: unknown tape header type 1853384566 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: Wed, 25 Mar 2009 16:45:43 -0000 On Wed, Mar 25, 2009 at 12:04:18PM -0400, Mikhail T. wrote: > Generally, when dumping read-write mounted filesystems, one is > supposed to use snapshots, but that is very buggy on its own > (leading to kernel crashes), so it is safer to rely on the FS being > "idle", if it can not be forced into read-only for some other > reason. Perhaps your kernel/world is not recent enough? There used to be problems with snapshots, including hangs or crashes, but IIRC, they disappeared completly a couple of months ago, at least for me. (no, sorry, I can't pinpoint the exact date, and much less the exact revision nr). Snapshots alone, and dump -L + restore (on RELENG_7/amd64) working flawlessly here on 20+ rack-mounted servers; some to tape, some to SAN, but I'm probably just lucky. BTW, that's what makes this problem so intractable: those who could debug it, can't reproduce it on their machines. It's scary to know there's a bug lurking in there. > -mi -cpghost. -- Cordula's Web. http://www.cordula.ws/