Hi,
    I am using KDUMP tools(version: 2.0.4) to capture kernel panic information. I configured the kernel compile para according to the kdump-tutorial, and get dump file in /var/crash/ through echo c > /proc/sysrq-trigger. but when I analyze the dump file using command:  crash -d8 vmlinux dumpfile
error happens as following:
crash: seek error: kernel virtual address: c1625ccc  type: "cpu_possible_mask"
The more log can be seen in the attachment: crash.log

Otherwise, I found the size of dump file(dump-incomplete) is about 25M, but my memory is 4G. why the dump file is so small?
My linux version is linux Mint15, basing on Ubuntu, the kernel version is 3.8.13.

v10@COS-Desktop ~ $
v10@COS-Desktop ~ $ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.8.13.13-cos-i686 root=UUID=c0bd0f62-0dfa-4425-8afa-b5ff8a00df5c ro crashkernel=384M-2G:64M,2G-:128M quiet splash
v10@COS-Desktop ~ $
v10@COS-Desktop ~ $ cat /var/crash/kexec_cmd
/sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-3.8.13.13-cos-i686 root=UUID=c0bd0f62-0dfa-4425-8afa-b5ff8a00df5c ro quiet splash irqpoll maxcpus=1 nousb " --initrd=/boot/initrd.img-3.8.13.13-cos-i686 /boot/vmlinuz-3.8.13.13-cos-i686
v10@COS-Desktop ~ $
v10@COS-Desktop ~ $

other log:
v10@COS-Desktop ~ $ sudo crash --minimal kdump/0211/vmlinux  /var/crash/201402120848/dump-incomplete
[sudo] password for v10:

crash 6.1.6
Copyright (C) 2002-2013  Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
Copyright (C) 1999-2006  Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011  NEC Corporation
Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions.  Enter "help copying" to see the conditions.
This program has absolutely no warranty.  Enter "help warranty" for details.
 
GNU gdb (GDB) 7.3.1
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...

NOTE: minimal mode commands: log, dis, rd, sym, eval, set, extend and exit

crash>
crash>
crash> rd linux_banner 30
rd: seek error: kernel virtual address: c1622080  type: "32-bit KVADDR"
crash>
crash>
crash>

I appreciate your help. Thanks!