ubuntu 12.04 configure the kernel crash to automatically restart and dump

By default, ubuntu12.04 does not configure the automatic restart and dump of kernel crashes. When a kernel crash occurs, there is no core dump file to analyze, and it is stuck on the kernel crash interface. In order to find the cause of the kernel crash, you need to configure the automatic restart of the kernel crash. And kernel dump configuration, the configuration steps are as follows:

The first step is to configure the kernel to restart automatically when it crashes

Add kernel.panic to the kernel parameter, 10 means the system will automatically restart after 10 seconds of kernel crash

vi /etc/sysctl.conf 
kernel.panic =10

The second step is to verify whether the automatic restart mechanism takes effect, and sysrq needs to be configured

Add kernel.sysrq to the kernel parameters, 1 is effective

vi /etc/sysctl.conf 
kernel.sysrq =1

Run the command to make the configured parameters take effect, or restart the system

sysctl -p /etc/sysctl.conf

Check whether the configured parameters are valid

Simulate system kernel crash, press alt+sysrq+c at the same time, or run the following command

echo c  >/proc/sysrq

Watch to see the kernel crash, and count down to restart

The third step is to configure kernel dump

The newly installed system needs to be upgraded, otherwise the software cannot be installed through apt-get

apt-get update

Install kernel dump

sudo apt-get install linux-crashdump

Check whether it works

Test, simulate system kernel crash, press alt at the same time+sysrq+c three keys, or run the following command

It was found that the system crashed and got stuck, did not send or save, and did not restart!

After searching for information, sending such a situation may be related to the core dump memory configuration is not enough, so the core dum memory configuration is modified

Modified to 512M size

Regenerate grub.cfg

Test again and succeed.