<br><br><div class="gmail_quote">On Wed, Aug 17, 2011 at 6:16 PM, amit mehta <span dir="ltr"><<a href="mailto:gmate.amit@gmail.com">gmate.amit@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div class="im">> You need to configure kdump on your RHEL system to enable it to dump the<br>
> vmcore file when the panic happens... Kdump configuration is explained<br>
> below.. There is a crashkernel boot parameter to be passed to kernel to<br>
> specify the memory reserved for the crash kernel.<br>
><br>
> <a href="http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-kdump.html" target="_blank">http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-kdump.html</a><br>
><br>
> <a href="http://www.mindtwist.de/main/linux/11-red-hat/27-how-to-configure-kernel-dumps-on-rhel-5.html" target="_blank">http://www.mindtwist.de/main/linux/11-red-hat/27-how-to-configure-kernel-dumps-on-rhel-5.html</a><br>
><br>
> <a href="http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=/liaai/crashdump/liaaicrashdumpconfigkdump.htm" target="_blank">http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=/liaai/crashdump/liaaicrashdumpconfigkdump.htm</a><br>
><br>
><br>
> Thanks and Regards,<br>
> Sumeet<br>
<br>
<br>
</div>Thank you Sumeet for the link, I've enabled kdump on my machine by<br>
following the steps mentioned<br>
on the link above(<a href="http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-kdump.html" target="_blank">http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-kdump.html</a>)<br>
But it seems that there is some setup problem on my machine as<br>
invoking "crash" is giving me an error.<br>
see the logs below.<br>
<br>
<<<snip from /etc/kdump.cfg>>><br>
#raw /dev/sda5<br>
#ext4 /dev/sda2<br>
#ext4 LABEL=/boot<br>
#ext4 UUID=03138356-5e61-4ab3-b58e-27507ac41937<br>
#net my.server.com:/export/tmp<br>
#net <a href="mailto:user@my.server.com">user@my.server.com</a><br>
path /var/crash<br>
core_collector makedumpfile -c --message-level 1 -d 31<br>
#core_collector cp --sparse=always<br>
#link_delay 60<br>
#kdump_post /var/crash/scripts/kdump-post.sh<br>
#extra_bins /usr/bin/lftp<br>
#disk_timeout 30<br>
#extra_modules gfs2<br>
#options modulename options<br>
default halt<br>
<<<snip from /etc/kdump.cfg>>><br>
<br>
<br>
[root@rhel6 boot]# mkinitrd /boot/initrd-2.6.32-71.el6.x86_64kdump.img<br>
2.6.32-71.el6.x86_64<br>
<br>
[root@rhel6 ~]# service kdump restart<br>
Stopping kdump: [ OK ]<br>
Your running kernel is using more than 70% of the amount of[WARNING]u<br>
reserved for kdump, you should consider increasing your crashkernel<br>
reservation<br>
Starting kdump: [ OK ]<br>
<br>
[root@rhel6 ~]# service kdump status<br>
Kdump is operational<br>
<br>
I hit the crash again and this time there was a vmcore under<br>
/var/crash directory<br>
<br>
[root@rhel6 2011-08-17-17:50]# pwd<br>
/var/crash/2011-08-17-17:50<br>
<br>
[root@rhel6 2011-08-17-17:50]# du -sh vmcore<br>
43M vmcore<br>
<br>
These are the two debug rpms that i've installed for kernel symbols:<br>
[root@rhel6 ~]# rpm -qa|grep -i debug<br>
kernel-debuginfo-common-x86_64-2.6.32-71.7.1.el6.x86_64<br>
kernel-debug-debuginfo-2.6.32-71.7.1.el6.x86_64<br>
<br>
my production kernel, from which i've booted:<br>
[root@rhel6 ~]# uname -r<br>
2.6.32-71.el6.x86_64<br>
<br>
[root@rhel6 ~]# crash -s<br>
/usr/lib/debug/lib/modules/2.6.32-71.7.1.el6.x86_64.debug/vmlinux<br>
/var/crash/2011-08-17-17\:50/vmcore<br>
crash: invalid kernel virtual address: 7180 type: "possible"<br>
WARNING: cannot read cpu_possible_map < - ----------------------------<br>
crash: seek error: kernel virtual address: ffffffff8208e980 type: "xtime"<br>
<font color="#888888"><br>
<br></font></blockquote><div>Hi Amit,<br> It seems there is a bugzilla from Red Hat on this issue(680864) in RHEL 6.0 kernel. Please could you try this issue on RHEL 6.1 kernel ?<br> Also as mentioned in the <a href="https://bugzilla.redhat.com/show_bug.cgi?id=680864">https://bugzilla.redhat.com/show_bug.cgi?id=680864</a>, which is similar to your issue, you should be able to see the output of bt command and log command in the crash sesion. Please have a look at and let us know what you see.<br>
<br>Regards,<br>Sumeet <br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><font color="#888888">
-Amit<br>
</font></blockquote></div><br>