kdump - installation,configuration and testing

kdump Installation

yum install kexec-tools

kdump Configuration

Configure crash save area

--Say you have a disk and create ext3 filesystem on it: /dev/sdb1

--Add following in kdump.conf

echo 'default reboot
> ext3 /dev/sdb1' >> /etc/kdump.conf

--Add crashkernel argument in default kernel entry of grub.conf

grubby --args='crashkernel=512M@16M' --update-kernel=/boot/vmlinuz-$(uname -r)

--Add folowing to sysctl

echo 'kernel.sysrq = 1' >>//etc/sysctl.conf

--reboot system
--ensure kdump is operation

service kdump status

Initiating kdump

-Ensure sysrq is enabled

cat /proc/sys/kernel/sysrq

-Initiate kdump by crashing system

echo c > /proc/sysrq-trigger

-collecting dump
Once system will reboot, mount /dev/sdb1 and you case find vmocore

127.0.01-YYYY-MM-DD-HH:MM:SS/vmcore

Reference

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-kdump.html#s1-kdump-installation