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<h2><font color="#e00000">Extracting useful information from kernel crashes</font></h2>
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<h3><font color="#0000e0">Minimum information for kernel problems</font></h3>
Familiarize yourself with
<a href="report.html">the general bug reporting procedures</a>
first.
All of that will apply.
When reporting a kernel panic or crash, please remember:
<ul>
<li><em>We need the console output on the screen</em>.
Capture it and save it.
Serial consoles are best, but if you are on a VGA console you can
<a HREF="http://www.openbsd.org/faq/faq7.html">scroll the console back</a>
and take readable pictures with a phone or camera.<BR>
<li><em>If the kernel panicked we need the traceback.</em>
It may be displayed on the screen.
If you are at a
<tt><a href="http://man.openbsd.org?query=ddb&sektion=4&">ddb</a>></tt>
prompt, type <tt>trace</tt>.
If you are running SMP, use the <tt>mach ddbcpu N</tt> command for each
of the <tt>N</tt> processors you have and repeat the <tt>trace</tt>
command for each processor.<BR>
<li><em>We need the process list.</em>
Use the command <tt>ps</tt> to get us that.
</ul>
<em>
Reports without the above information are useless.
This is the minimum we need to be able to track down the issue.
</em>
<h3><font color="#0000e0">Additional information you can send</font></h3>
<P>
In some situations more information is desirable.
Below are outlined some additional steps you can take in certain situations:
<ul>
<li> ... XXX boot crash? XXX
<li> ... XXX show regs? XXX
<li> <em>If your crash appears to involve filesystems.</em>
The following additional things would be helpful
<ul>
<li> The output of the
<tt><a href="http://man.openbsd.org?query=ddb&sektion=4&">ddb</a>></tt>
command <tt>show uvm</tt>
<li> The output of the
<tt><a href="http://man.openbsd.org?query=ddb&sektion=4&">ddb</a>></tt>
command <tt>show bcstats</tt>
<li> The output of the <tt>mount</tt> command from your running machine,
so we know what filesystems are mounted and how.
</ul>
<li> <em>If your crash appears to involve hibernate/resume.</em> XXX
</li>
</ul>
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