misc/110711: no coredump after kernel panic

[Rajkumar S]

>Number:         110711
>Category:       misc
>Synopsis:       no coredump after kernel panic
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Mar 23 13:10:04 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Rajkumar S
>Release:        FreeBSD 6.1-RELEASE #0
>Organization:
Linuxense 
>Environment:
FreeBSD safenet.linuxense.com 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May  7 04:32:43 UTC 2006     root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386

>Description:
I am trying to get core dump of a kernel panic relating to safenet
driver, so that I can file a meaning full PR or even try to debug
myself. But I am not getting a core dump after panic. I have gone
through the developers manual and I believe I have taken care of all
the usual stuff.

dumpdev="/dev/ad2s1b"
dumpdir="/var/crash"
savecore_flags="-v -z"

hw.physmem: 508989440

Device          1K-blocks     Used    Avail Capacity
/dev/ad2s1b        768000        0   768000     0%

/dev/ad2s1d    989M    7.9M    902M     1%    /var

My kernel panics immediately on boot up, before the disks are probed.
After panic I boot with a different kernel to extract the core. But I
get the following error during boot up.

Checking for core dump on /dev/ad2s1b...
unable to open bounds file, using 0
checking for kernel dump on device /dev/ad2s1b
mediasize = 786432000
sectorsize = 512
magic mismatch on last dump header on /dev/ad2s1b
savecore: no dumps found

>How-To-Repeat:
This happens every time.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: