From mboxrd@z Thu Jan 1 00:00:00 1970 From: "S. J. van Harmelen" Subject: Re: Possible bug in multipathd (getting a segfault) Date: Tue, 20 Nov 2007 11:34:37 +0100 Message-ID: <1195554877.6329.31.camel@sanderbal> References: <1195480602.6074.3.camel@sanderbal> <47419854.2000508@linpro.no> <1195484847.6074.16.camel@sanderbal> <20071119185021.GA23100@us.ibm.com> <1195506996.11489.23.camel@sanderbal> <47428E96.2090008@linpro.no> <1195551419.6329.14.camel@sanderbal> <4742AD9E.7060601@linpro.no> <1195553418.6329.23.camel@sanderbal> <4742B51F.2050907@linpro.no> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4742B51F.2050907@linpro.no> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids On Tue, 2007-11-20 at 11:21 +0100, Tore Anderson wrote: > * S. J. van Harmelen > > > Could you specify the steps I have to take to create the backtrace a > > bit more as I have not done this before. > > > > I run a debian etch server with a custom compiled 2.6.23.1 kernel > > when I get the error. > > Debian strips all their binaries by default, so you need to recompile > multipath-tools and reinstall it: > > $ export DEB_BUILD_OPTIONS=nostrip > $ apt-get build-dep multipath-tools > $ apt-get --compile source multipath-tools > $ dpkg -i multipath-tools*deb I guess I don't have to do that as I compiled the multipath-tools myself? wget http://christophe.varoqui.free.fr/.../multipath-tools-0.4.8.tar.bz2 tar jxf multipath-tools-0.4.8.tar.bz2 cd multipath-tools-0.4.8/ make make install I did compile them when running the 2.6.22.2 kernel though. Should I recompile them when running the 2.6.23.1 kernel, or doesn't that matter? > > Then start multipathd from a shell that has core dumps enabled (make > sure it's not already running): > > $ ulimit -c unlimited > $ multipathd > > Wait for a segfault to happen, and you should have gotten a file named > "core" in your current directory (or maybe in the root directory since > multipathd chdir()s there, I'm not sure) that contains the backtrace. > We need to extract it with GDB, though, so run: > > $ gdb /sbin/multipathd /path/to/core > (gdb) bt full Oke, the segfault happens right at the start (and only at the start), so that shouldn't be a problem. But I have to stop the running mulipathd and that seems like a problem. This machine is running in production :) So that will have to wait until I get a maintance window I guess... > > ...and post the resulting backtrace here. Hopefully a developer (not > me, unfortunately) will be able to make sense of it. > > Another thing you might want to try is to use your 2.6.23.1 with the > same configuration as your 2.6.22.x (ie. don't use hwhandler rdac), and > see if the segfaults still occur. > > Regards