Date: Sun, 25 Nov 2007 18:29:14 -0800 (PST) From: Jeremy Chadwick <koitsu@FreeBSD.org> To: FreeBSD-gnats-submit@FreeBSD.org Subject: conf/118255: savecore never finding kernel core dumps (rcorder problem) Message-ID: <20071126022914.DBBF11CC07B@mx01.sc1.parodius.com> Resent-Message-ID: <200711260230.lAQ2U1RP000303@freefall.freebsd.org>
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>Number: 118255 >Category: conf >Synopsis: savecore never finding kernel core dumps (rcorder problem) >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon Nov 26 02:30:01 UTC 2007 >Closed-Date: >Last-Modified: >Originator: Jeremy Chadwick >Release: FreeBSD 6.3-PRERELEASE i386 >Organization: >Environment: System: FreeBSD eos.sc1.parodius.com 6.3-PRERELEASE FreeBSD 6.3-PRERELEASE #0: Wed Nov 7 13:14:24 PST 2007 root@eos.sc1.parodius.com:/usr/obj/usr/src/sys/EOS i386 >Description: One of our production systems has begun kernel panic'ing for reasons unknown; we're in the process of figuring out why that's happening. On the other hand, none of our kernel panics (which are being written to disk when doing "panic" from DDB) are being dropped into /var/crash when savecore runs. Details of our configuration and what actually happens were posted to freebsd-stable. It shows that a kernel core dump is indeed written to the correct device (/dev/ad0s1b), but savecore never detects the cores: http://lists.freebsd.org/pipermail/freebsd-stable/2007-November/038069.html http://lists.freebsd.org/pipermail/freebsd-stable/2007-November/038569.html I believe the problem is that /etc/rc.d/swap1 (which does `swapon -a`) is being called _before_ /etc/rc.d/savecore, thus clobbering/stomping over any core dumps that exist. See the 2nd URL above for some additional details. I'm marking this serious/medium because people being able to get vmcore images after a kernel panic is important. :-) >How-To-Repeat: Set dumpdev and dumpdir in /etc/rc.conf, panic system, and see. >Fix: I believe the issue can be fixed by adjusting some of the rcorder(8) values so that savecore gets run *before* swap1. I'm not familiar with what needs to be changed to make this work. >Release-Note: >Audit-Trail: >Unformatted:
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