Configure Xendump for Oracle EL Linux 5.9 xen guest

this post also works for Redhat EL5 compatible.

My Configuration:

Host: testbox       2.6.18-128.2.1.4.37.el5xen  EL5.7
Gust: testbox-vm1   2.6.18-348.el5              EL5.9

Steps:

   1. on Host, enable dumps and restart xend service.

[root@testbox xen]# vi /etc/xen/xend-config.sxp
enable dump:
  (enable-dump yes)

restart xend service:
[root@testbox xen]# service xend restart

As the root part on my box doesnt have enough space(2G+) for crash cores. using following link

[root@testbox 21_testbox-vm1]# rm -fr /var/xen/dump/
[root@testbox 21_testbox-vm1]# ln -s /var/ovs/mount/CC94A2F6CC2A4FD2957BB3FE6B6BA694/suse /var/xen/dump

 

   2. change vm1 guest cfg file.
[root@testbox running_pool]# pwd
/var/ovs/mount/CC94A2F6CC2A4FD2957BB3FE6B6BA694/running_pool

[root@testbox running_pool]# cd 21_testbox-vm1/
[root@testbox 21_testbox-vm1]# vi vm.cfg
enable:
on_crash = ‘coredump-restart’     
on_reboot = ‘restart’

shutdown vm using cmd: (If the box is not yet created, no need to shutdown, just create a new.)
xm shutdown 21_testbox-vm1
restart vm using new cfg:
xm create  21_testbox-vm1 -f ./vm.cfg

3. inside vm1.

enable sysrq:

kernel.panic_on_oops=1
kernel.panic=1
kernel.sysrq = 1

       choosing RH compatible kernel, instead of the UEK kernel for dumps.
--OEL5 UEK kernel not working well with xendump service.

[root@testbox-vm1 ~]#  vi /etc/grub.conf
default=1    <– the # of RH kernel

We are now using kernel:
kernel-2.6.18-348.el5
Install following RPMs for further cases:

kernel-debuginfo-2.6.18-348.el5
kernel-xen-2.6.18-348.el5
kernel-debuginfo-common-2.6.18-348.el5

reboot the guest, root access and issue:
[root@testbox-vm1 ~]# echo c >/proc/sysrq-trigger

a new core was generated in Host:

[root@testbox dump]# pwd
/var/xen/dump
[root@testbox dump]# ls
2014-0219-0905.44-21_testbox-vm1.49.core

 

4. how to analyze the core.

scp the core into testbox-vm1. for example:
(there should be some other ways to share files between guest/host, like via NFS)

[root@testbox-vm1 0013]# pwd
/var/crash/0013
[root@testbox-vm1 0013]# ls
2014-0219-0905.44-21_testbox-vm1.49.core

        issue crash utility:

 

[Test:]

[suse@suse ~]$ssh root@testbox-vm1
[root@testbox-vm1 ~]# echo c >/proc/sysrq-trigger

a new core (sizeof 2G, memsize of the guest vm1) is generated in testbox:/var/xen/dump

[Reference:]
How to enable automatic core dumps of xen guests?
Core dump Xen domU/guests