Reboot Linux box after a kernel panic

last updated in Categories CentOS, Debian Linux, Gentoo Linux, Hardware, Howto, Linux, RedHat/Fedora Linux, Tips, Troubleshooting, Tuning

If you want the server to get rebooted automatically after kernel hit by a pain error message, try adding panic=N to /etc/sysctl.conf file.

It specify kernel behavior on panic. By default, the kernel will not reboot after a panic, but this option will cause a kernel reboot after N seconds. For example following boot parameter will force to reboot Linux after 10 seconds.

Open /etc/sysctl.conf file

# vi /etc/sysctl.conf

When kernel panic’s, reboot after 10 second delay

kernel.panic = 10

Save and close the file. Alternatively, you may want to enable and use magic system request keys (SysRq).

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

4 comment

  1. Thanks for this tip. My computer had a kernel panic for the first time a couple of weeks ago and I had no choice but to reboot it manually.

  2. One can also add panic=10 to the kernel command line, it will have exactly the same effect.

    Of course, it’s possible to change it later with sysctl, or by writing to /proc:

    echo 10 > /proc/sys/kernel/panic

  3. Thanks for this tip! As indicated by mangoo: To take this change effect right now, issue the command
    sysctl -p to re-read the /etc/sysctl.conf
    Otherwise, this change is not active before the next reboot.

  4. It’s important to mention that there is another “key” named “panic_on_oops” that should also be defined to some amount of seconds to reboot kernel on an “oops” kind of panic. I had this situation and the console had frozen and not even SYSRQ could restart the machine. The crash dump couldn’t be saved because I had to remove power from device (embedded device without reset button) to restart it and the power off procedure avoids memory to be saved after panic.
    Making “echo 1 > /proc/sys/kernel/panic_on_oops” or “kernel.panic_on_oops=1” on /etc/sysctl.conf solved my problem of restarting after this oops panic.

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