conf/118255: savecore never finding kernel core dumps (rcorder
koitsu at FreeBSD.org
Sun Nov 25 18:30:03 PST 2007
>Synopsis: savecore never finding kernel core dumps (rcorder problem)
>Arrival-Date: Mon Nov 26 02:30:01 UTC 2007
>Originator: Jeremy Chadwick
>Release: FreeBSD 6.3-PRERELEASE i386
System: FreeBSD eos.sc1.parodius.com 6.3-PRERELEASE FreeBSD 6.3-PRERELEASE #0: Wed Nov 7 13:14:24 PST 2007 root at eos.sc1.parodius.com:/usr/obj/usr/src/sys/EOS i386
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:
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. :-)
Set dumpdev and dumpdir in /etc/rc.conf, panic system, and see.
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.
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