How do permanently add kernel command line parameters to grub

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Suppose, you want to permanently add/modify a kernel command line parameter to grub, for example we want to specify kernel to reboot after 5 seconds on a panic message. The kernel command line parameter for this.

panic=5

One option is while the grub menu is loading you can press 'e' and add it, but this is not persistent in reboots. To make it permanent, the GRUB provides a configuration option GRUB_CMDLINE_LINUX which adds command-line  arguments to the menu entries for the Linux Kernel.


Open /etc/default/grub using vim, requires sudo permission: sudo vi /etc/default/grub

Save the file : ":wq" command
Then run "update-grub" command to add these commands to /boot/grub/grub.cfg file
Finally reboot to reload the kernel parameters.

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