From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx03.extmail.prod.ext.phx2.redhat.com [10.5.110.7]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id nBAF8EO8003860 for ; Thu, 10 Dec 2009 10:08:14 -0500 Received: from vms173007pub.verizon.net (vms173007pub.verizon.net [206.46.173.7]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nBAF83Mh028262 for ; Thu, 10 Dec 2009 10:08:03 -0500 Received: from backoffice.bplinux.com ([98.118.141.73]) by vms173007.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KUF00C14ZCYUOBO@vms173007.mailsrvcs.net> for linux-lvm@redhat.com; Thu, 10 Dec 2009 09:07:50 -0600 (CST) Received: from localhost (localhost.localdomain [127.0.0.1]) by backoffice.bplinux.com (Postfix) with ESMTP id BE7603E8002 for ; Thu, 10 Dec 2009 10:04:45 -0500 (EST) Received: from backoffice.bplinux.com ([127.0.0.1]) by localhost (backoffice.bplinux.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0Ov3XWeB3jk7 for ; Thu, 10 Dec 2009 10:04:41 -0500 (EST) Received: from backoffice.bplinux.com (backoffice.bplinux.com [192.168.1.4]) by backoffice.bplinux.com (Postfix) with ESMTP id 251923E8001 for ; Thu, 10 Dec 2009 10:04:41 -0500 (EST) Date: Thu, 10 Dec 2009 10:04:40 -0500 (EST) From: Christopher Hawkins Message-id: <8023092.631260457480892.JavaMail.javamailuser@localhost> In-reply-to: Subject: Re: [linux-lvm] kernel panic on lvcreate MIME-version: 1.0 Content-transfer-encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development It is reported here: https://bugzilla.redhat.com/show_bug.cgi?id=539328 That is definitely the one. And it sounds like they have a potential fix... I have already emailed the developers there asking if I can help test their patch, so hopefully soon I can post back and report status. Christopher Hawkins ----- "Stuart D. Gathman" wrote: > On Wed, 9 Dec 2009, Christopher Hawkins wrote: > > > After some time I revisited this issue on a freshly installed Centos > 5.4 box, > > latest kernel (2.6.18-164.6.1.el5 ) and the panic is still > reproducible. Any > > time I create a snapshot of the root filesystem, kernel panics. The > LVM HOWTO > > says to post bug reports to this list. Is this the proper place? > > Bummer. I would post the bug on Centos bugzilla also. Please post > the > bug number here if you do it (cause I'll get to it eventually). > > Thanks for testing this. I have the same problem, and have a new > client > to install by next year - so not much time to work on it. > > Now that we know it is not yet fixed, we can form theories as to what > is going wrong. My guess is that the problem is caused by the fact > that > lvm is updating files in /etc/lvm on the root filesystem while taking > the snapshot. These updates are done by user space programs, so I > would > further speculate that *any* snapshot would crash if an update > happened exactly > when creating the snapshot - i.e. the atomic nature of snapshot > creation has > been broken. The lvm user space probably does fsync() on files > in /etc/lvm, which might be involved in triggering the crash. > > We could test the first theory by moving /etc/lvm to another volume > (I > sometimes put it on /boot - a non LVM filesystem - for easier > disaster > recovery.) Naturally, I wouldn't go moving /etc/lvm on a production > server. > > Testing the second hypothesis is less certain, and would basically > involve > trying snapshots of LVs undergoing heavy updating. > > -- > Stuart D. Gathman > Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 > 591-6154 > "Confutatis maledictis, flammis acribus addictis" - background song > for > a Microsoft sponsored "Where do you want to go from here?" > commercial. > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/