kgdb doesn't seem to work, says "Cannot read PTD"

[Aurel Bodenmann]

Hello!

My FreeBSD box is giving me quite a hard time, it panics from time to  
time (normally after a few days uptime), I suspect it has something  
to do with this cheap SATA controller I'm using (Promise SATA150  
TX4). Anyway, I wanted to locate the problem and do something about  
it (aka submit an useful coredump to this list :-) but unfortunately  
neither gdb nor kgdb seem to work for me. I've tried to make a  
coredump as described in [1] and have now a kernel.debug file  
(containing the kernel with debug information) and a vmcore.1 file  
(whose size is 768MB as it should be). Now, I'm trying to open these  
two with

gdb -k kernel.debug vmcore.1

but it says

gdb: unrecognized option `-k'
Use `gdb --help' for a complete list of options.

so I read the manpage only to find out that -k still exists and that  
it should work like described in [1]. Ok, so I've tried kgdb but it  
gives me an error too:

root> kgdb kernel.debug vmcore.1
kgdb: cannot read PTD

after some googling I found out, that some people are having the same  
trouble ([2] and [3]) but unfortunately I couldn't find any advice on  
how-to create an useful coredump without using kgdb or gdb. I would  
really appreciate if someone could help me, I would like to help on  
this bug.

Thanks, Aurel Bodenmann

[1] http://www.onlamp.com/pub/a/bsd/2002/04/04/Big_Scary_Daemons.html
[2] http://lists.freebsd.org/mailman/htdig/freebsd-hackers/2005-April/ 
011461.html
[3] http://lists.freebsd.org/pipermail/freebsd-stable/2005-May/ 
014515.html

-- 
5 GB Mailbox, 50 FreeSMS http://www.gmx.net/de/go/promail
+++ GMX - die erste Adresse für Mail, Message, More +++